I'll tell ya what I see: no rollers. Pins rubbing (wearing) both sides of the tooth. Including the back side, which will never exert any forward longitudinal force on a chain unless it's made of magnets. I also see a highly suspect FEA diagram on the right, where teeth not even engaged still show non-zero stresses (lighter blue, not the darkest blue), indicating that the color/stress scale has been changed compared to the baseline on the left. So it's not an honest comparison. Add to that the fact that this is a 'better mousetrap' that requires you to first replace all the mice in the house, and I guess I'm a bit (to use one of Bike Snob NYC's favorite words) nonplussed.
pengaru 1229 days ago [-]
I suspect lack of need for rollers is a primary feature.
Conceptually, to me, the new interior bits serve as a sort of individual tooth holder that is free to rotate with the tooth as the tooth orbits the axle. So there's not much friction at the tooth:holder junction as the sprocket turns.
That friction is now occurring at the narrower intersection of a hinged tooth holder and chain link. Being a narrower hinge joint, just the length of a chain link's thickness, it has less surface area for friction, and less room for debris ingress etc.
Conventional chains rotate a pin across the sprocket's thickness, and AIUI use a roller to try keep debris out of and lubricant within that interface to reduce friction. This contraption takes it a step further.
You can actually envision the tooth holder as analogous to the roller in a conventional chain, just with less surface area at the twisting intersection. They've obsoleted the conventional roller.
rconti 1229 days ago [-]
I don't know anything about FEA, but in reading this article and thinking it through, was the first time it hit me how bad a conventional chain and sprocket is. On a brand-new set with perfect tolerances, you might be able to use many of the front side of many of the teeth, but as SOON as the chain begins to stretch (wear) even fractionally, most of the stress goes to the 'first' teeth in any given power stroke, and the same spot on the chain. I imagine if you're putting, say, 1000w through 2 teeth and 2-4 chain endplates, wear is an order of magnitude higher than if you're able to effectively transfer power through double the teeth and endplates.
Likely the "pins rubbing" you mention doesn't really matter, because the wear from inserting and removing the chain as it cycles around has to be a miniscule fraction of the wear that occurs under load.
Obi_Juan_Kenobi 1229 days ago [-]
Bike chain teeth do not have straight sides or a convolute profile. They are wedges that act as ramps for the rollers. As the chain wears, it is no longer possible for the rollers to all sit at the base of the teeth. Instead, to account for the increased pin-pin distance, they begin to ride 'up' the teeth at the point of first engagement. You can easily see this when looking at a worn cassette used with a stretched chain. The tooth profiles become sharply hooked as the roller wear works in from the 'side' of the tooth. https://pbs.twimg.com/media/EFYuxlJXYAA89-b.jpg Note that the lowest point of the profile remains at the original base of the tooth, and then is angled up.
In a worn chain, the rollers engage high up, and then work their way down (under high load) until seated at the base. In the unworn condition, engagement begins at the base of the tooth where the forces are better spread over the roller.
In point of fact, the forces are spread out over more teeth when worn. The first tooth engagement might begin 3mm high, then 2.5mm, then 2mm, etc. over ~6 teeth. Whereas the fresh chain might manage 2 or 3. But the wear and friction of the worn chain is much higher as you have a great deal of motion under high load as the loaded rollers creep down. The unworn chain has perhaps higher loads, but the roller is essentially seated and immobile at the base of the gear for this.
foobar1962 1228 days ago [-]
> ..it hit me how bad a conventional chain and sprocket is.
Not at all! The article claims 98% efficiency.
Roller chains are used to transfer torque in bicycles and motor cycles, inside internal combustion engines to drive cam shafts... and many more applications covering a huge range of power levels and environments.
Not only is it efficient, it's cheap.
If that last 2% of efficiency was important (or easy to obtain) it would have been on a GP motorcycle already.
jacquesm 1228 days ago [-]
A chain is an extremely efficient way of transferring power. A similar arrangement made with gears would be much less efficient (even if it could be made much more durable, but not at the same total weight).
to11mtm 1229 days ago [-]
If this chain is truly more efficient and/or durable, I would expect them to be selling to two specific markets:
- BMX: This market would be all over anything that would be an improvement in durability, and frankly a percentage would just do it for the different tooth design.
- Auto: Admittedly, the site for the company that is making this new chain mentions automotive in a blog post, but I don't see anything specific to an automotive product. A more durable and efficient timing chain is something I'd expect most of the automakers to care about.
dharmab 1229 days ago [-]
Tangent: BMW has developed a new diamond-coated chain for motorcycles which they claim requires no regular maintenance. (Motorcycle chains, which are external and near the ground, have to be cleaned and re-lubricated every 300-500 miles for maximum life.)
Another point: BMW Motorrad has used driveshafts on their bikes since the 80s. In a conventional setup much like a automobile. The only real majntaining is to lube the end gear which sits in a kind of differential housing (there's no diff, but imagine how a car's driveshaft connects to the rear axle).
My bike (a k75) has it and well it's pretty cool!
dharmab 1228 days ago [-]
That's only on the touring models, where the lower maintenance intervals justify the weight and inefficiency. The smaller off-road models like my F750GS and the performance-oriented models like the S1000R use chains for durability/repairability and efficiency.
bch 1228 days ago [-]
It’s every K and R bike they’ve make since the 1930s (for the R models), including touring bikes but also the GS (which perhaps is a tourer these days, granted), R Nine T (street/sport), R18 (bobber/cruiser), and R1250R roadster.
jacquesm 1228 days ago [-]
Since the 80's? Much further back: 1923 to be precise.
loeg 1228 days ago [-]
What do they make the cogs out of?
dharmab 1228 days ago [-]
Motorcycle sprockets are usually made from steel (longer lasting) or aluminum (lighter). The sprockets need minimal cleaning and lubrication and usually wear out at the same time or after the chain, in my experience. The chain and sprockets are replaced as a set, as using a new chain on a worn sprocket can accelerate wear.
loeg 1228 days ago [-]
If the chains are coated in super hard diamond, won't the sprockets wear much faster?
collyw 1228 days ago [-]
BMX? Most BMXers I see use pretty minimal setups, only one brake if at all. Durability is more relevant to a fall than for actual power transmission, they only have one gear.
baybal2 1229 days ago [-]
I'm afraid this is kind of a scam too.
The solution clearly loses on weight/benefit ratio to just making a thicker chain.
pcl 1228 days ago [-]
At the pro level, bicycles are regularly below regulation weight, and then dead weight is added to get back to spec. So, there is budget for extra weight for higher performance parts.
However, the rule of thumb is to minimize rotational weight (e.g., wheels) due to the increase in rotational inertia. I wonder whether chain weight is similarly problematic.
aardvarkr 1228 days ago [-]
Just for argument’s sake, does rotational weight really give a performance impact? I expect it marginally improves initial acceleration but I also expect top speed is unchanged. Heavier wheels would allow you to coast for longer without needing to pedal (conservation of momentum) but besides the initial acceleration performance is mostly unchanged. Unless you’re constantly stopping and starting idk if it makes much difference. Similarly, I’d expect the chain’s weight to have a minuscule impact on acceleration but the increased efficiency sounds like it is several orders of magnitude beyond whatever trade off there is to a slightly heavier chain.
It's interesting to look into what's actually scientifically supported in biking and other sports, and the implied effect sizes.
pcl 1228 days ago [-]
In many types of races, cyclists are pretty much constantly changing speed, so the extra inertia matters a fair bit.
Often, races are won and lost in the final dash to the finish line, which is pretty much all about acceleration.
TylerE 1228 days ago [-]
Yes. More rotating weight = more energy expended to accelerate the wheel.
ComputerGuru 1229 days ago [-]
> I guess I'm a bit (to use one of Bike Snob NYC's favorite words) nonplussed.
JK Rowling taught me that nonplussed is apparently a part of the daily vernacular in the UK.
rdiddly 1229 days ago [-]
I like how it can mean either 'confused' or 'unimpressed' which in certain situations can almost be opposites of each other. But both apply to me with this chain system!
switch007 1229 days ago [-]
I (a Brit) was confused by the apparent use to mean "unimpressed" but I stumbled upon this:
> Note: The use of nonplussed to mean "unimpressed" is an Americanism that has become increasingly common in recent decades and now appears frequently in published writing. It apparently arose from confusion over the meaning of nonplussed in ambiguous contexts, and it continues to be widely regarded as an error.
Well I (a Brit) have only ever understood it to mean 'not sufficiently impressed to know what to say'; in a sort of bemusement or indecision as to one's reaction. A sort of confusion as to how unimpressed one is. The Collins dictionary I have to hand doesn't capture that nuance though.
I actively try to avoid USAmericanisms, except for "y'all". Go figure ;o)
[That last phrase is a USAmericanism, used for amusing intent.]
HelloMcFly 1228 days ago [-]
Y'all fills a hole in the English language that is not suitably filled by any other single word! It's a great word!
jacobolus 1229 days ago [-]
Nonplussed means “so confused that you are completely paralyzed”. Think deer stopped in headlights.
Using nonplussed to mean “unimpressed” or “apathetic” will leave listeners both unimpressed and confused.
raverbashing 1228 days ago [-]
> NOTE: The use of nonplussed to mean "unimpressed" is an Americanism that has become increasingly common in recent decades and now appears frequently in published writing. It apparently arose from confusion over the meaning of nonplussed in ambiguous contexts, and it continues to be widely regarded as an error.
My observation: "continues to be regarded as an error" is a bit of a "that's not how linguistics work" thing
forest_dweller 1229 days ago [-]
Not really. I've never heard it used in the the general publice. It is normally used by office manager types and by talking heads in politics.
Symbiote 1229 days ago [-]
My dad managed to say it about once a week, generally when describing disappointing work or behaviour from the children at his school.
filterfish 1229 days ago [-]
Granted, it's not a common but it's not uncommon.
usrusr 1229 days ago [-]
I really don't get it: what power are they claiming to be transferring on the side of the tooth that isn't engaging with a roller chain?
Also note that this is only for track bikes with a perfectly straight chainline (technically speaking it would also work for internal gear hubs wish are increasingly driven by belts in the upper price range). The shifting chain that is deployed diagonally more often than straight is an entirely different beast, in theory much worse in efficiency and durability. Pretty much all practical durability limits stem from compromises done for that diagonal capability for sitting. Which basically goes ruthlessly against all mechanical engineering rules, like the old adage about how bumblebees were supposedly unable to fly. Yet even they work quite well, given that challenging background they work just awesome and track chains already work better than that.
lostlogin 1229 days ago [-]
Internal hubs are amazing and so great to use, until you get a puncture. It’s such a nightmare and I went through so many of those dumb proprietary nuts that strip so easily.
Bikes like the Cannondale Bad Boy have got me thinking, what if the single fork was at the rear? Then you could have an internal hub and change the tube without the extra suffering. Yes, the loading at the read would be significantly greater, but if it were possible it would make internal hubs much better.
rconti 1229 days ago [-]
Oh god. I have a Ghost commuter bike with belt drive (came with Continental, but it broke and couldn't be replaced, so it was swapped to gates). Not only is a it a huge pain in the ass to carry two identical heavy wrenches in case you have to remove the wheel+belt in the field, and tension is hard to get right even at home, but of course the cable is extremely hard to remove the first handful of times (and which gear you have to be in changes from hub to hub), ... but my Ghost had a disc brake caliper located such that the caliper had to be removed in order to remove the rear wheel (the disc cannot just side out of the caliper, it hits the caliper body itself). Ugh.
teva 1229 days ago [-]
Do you know you don't have to remove the wheel to repair a puncture ? Remove one side of the tire from the rim and pull the inner tube, then patch it.
xorcist 1228 days ago [-]
Isn't hard to find small punctures with the tube still stuck around the wheel?
zrobotics 1228 days ago [-]
Partially inflate the tube after the tire is pulled aside, then run a mixture of soapy water over the tube. Sure, the tire is a bit in the way, but that is still less hassle than removing the wheel. The only real danger is that the tube needs to be treated carefully to keep it from snagging on things and causing more damage.
jacquesm 1228 days ago [-]
Indeed. The only time you remove the wheel is to replace the tires.
mpol 1229 days ago [-]
I don't think internal hubs are amazing :)
Derailer systems only absord energy in the chain and bearings, and a well maintained system can maybe lose 1.5% of energy. Internal hub gearing can lose around 15% energy.
The shop keeper won't tell you this, he just wants to sell you a bike. If he starts talking difficult things, buyers might just go to the next shop to buy what they had already chosen.
usrusr 1229 days ago [-]
Internal hubs are amazing for the kind of bike that's always outside and gets maintenance beyond occasional tire pumping about as often as summer olympics are opened. Unfortunately SRAM stopped production of the T3 years ago, it was the perfect drive for a low maintenance, low value practical utility bike, providing the easy 80% of everything you want from bicycle gears for short distance commuting. Derailleur systems receiving a similar lack of maintenance are what turns people into short distance drivers.
war1025 1228 days ago [-]
> Derailleur systems receiving a similar lack of maintenance are what turns people into short distance drivers.
Funny, I thought it was my three young kids that did that.
I always had a mountain bike growing up. Having now transitioned to more of a road bike, the difference in rideability is pretty stark.
I guess it could be the derailleur, but I assumed it was the tires and gearset that made it a pain to get places. I also have noticed a night and day difference when my tires are properly inflated. I just replaced the tubes and tires so maybe I'll have better luck now, but previously I needed to refill the tires basically daily to keep them in the right range.
jmartinpetersen 1228 days ago [-]
My nine year old isn't responsible enough to care for a derailleur (let alone park his bike instead of throwing it on the ground), but he can bike to school just fine with his internal hub and 15 % energy loss.
NLips 1228 days ago [-]
The only reasons for needing to reinflate every day should be:
1) using latex inner tubes. They’re lighter, but don’t hold air so well. Fine for racing, impractical for normal use
2) a slow puncture
jacquesm 1228 days ago [-]
3) broken valve
4) badly seated valve tip (dirt?)
scns 1228 days ago [-]
Schwalbe recommends inflating once a month on butyl tubes.
olau 1229 days ago [-]
I have looked a several charts, and that is not an honest comparison. A derailleur will not be 1.5% energy loss across all gears. And I've not seen a chart for an internal hub that had 15% energy loss across all gears.
If you actually take a look at your derailleur system, you'll notice that a) the chain is not straight in all but a few settings, b) it has a somewhat complicated arm with an extra sprocket to keep the chain tight. And it is harder to protect it with a guard, so you end up with more dirt in the system if you use it every day.
But yes, internal hubs are heavier, generally somewhat less efficient, and better protected against the elements.
lostlogin 1229 days ago [-]
I got it for free as a hand-me-down so I do think I can be fairly objective about it. I’m surprised to hear the energy loss is that high. It was paired with fast tires and that bike could move quickly. The downsides of having to adjust and maintain the wheel position were not a worthwhile trade off though, but it was so close.
jacquesm 1228 days ago [-]
The only internal geared hubs that lose 15% of energy are the ones that are constant variable ratio drives. The rest of them are extremely good and lose < 3% power, on par with a derailleur system that has seen regular maintenance, a bit worse than a derailleur in perfect (new!) shape.
justinator 1229 days ago [-]
You don’t always have to take a wheel off to fix a flat with a patch and completely tubeless setups are fairly commonplace now.
lmm 1229 days ago [-]
The Strida Evo works like that: hub gears, but both wheels are single fork.
gameswithgo 1229 days ago [-]
bikes like that have existed, its possible.
might be heavier by a bit.
usrusr 1229 days ago [-]
Just had an idea [1] about how this "gripper chain" could maybe outdo a roller chain in efficiency:
Maybe the "gripper plates" align themselves perfectly with the tooth at a time when the connection is still not under load yet? A conventional roller won't need much aligning, but it won't do that, it won't settle into place before load is applied. Friction scales with force. If that's how they teased out a minor delta then it's truly very clever (but likely still highly impractical outside the laboratory/indoor track setting)
[1] idea came while taking a shower, were else. Shower after churning that old Campag 12s chain a little, unfortunately only on Zwift these days
ska 1229 days ago [-]
I don't think they are claiming any power is transferred by the other side, just that it forces a more uniform fit and distributed the power transfer over more teeth.
mdoms 1229 days ago [-]
They very much are making that claim.
> The future apparently isn’t far away, as New Motion Labs has developed a new Dual Engagement chain that is supposedly able to transfer high power on both sides of the tooth, over nearly all the teeth available to the chain.
davidw 1229 days ago [-]
> According to New Motion Labs, because the chain engages on both sides of the tooth, it is effectively locked in position, theoretically spreading the power distribution over many teeth, increasing efficiency, and reducing wear.
Yeah, I'm also wondering about how much energy it takes to "lock it in place", and then, of course, unlock it.
I've been a cyclist for 30 years now, and there's always been a steady stream of 'amazing! revolutionary!' things like this, but mostly it's incremental improvements. If it pans out, great, if not, c'est la vie.
usrusr 1229 days ago [-]
Spreading over many teeth is very interesting, I'm pretty sure that it doesn't happen in real life. You'd need elasticity to exceed imprecision and there's definitely no place anywhere in chain or sprocket were you'd not try to avoid as much elasticity as you can.
1229 days ago [-]
usrusr 1229 days ago [-]
See my other post theorizing about how it might actually be advantageous despite looking crazy. Perhaps a case of marketing guy who doesn't really understand what he's selling effectively outranking the engineer?
aasasd 1229 days ago [-]
Elementary: one roller pushes the tooth, the other one pulls.
usrusr 1229 days ago [-]
How would a roller pull? Magnetism? Suction? Capturing the tooth in engaging conversation?
aasasd 1229 days ago [-]
Black magick.
leoh 1229 days ago [-]
Great chain, but the Gates Carbon Drive is likely a superior technology. Europe has largely adopted it, but it is rare in the states. I have a Riese & Müller bike with a Gates Carbon Drive and it is absolutely lovely. Silent, but best of all, no grease on my pants or hands, ever. They handle dirt and dust super well (just dry off and wipe down with a cloth/no gears get jammed with a sealed planetary gear system). It also is said to last thousands of miles, if not 1e4 miles+.
owenversteeg 1229 days ago [-]
I live in the Netherlands and have traveled Europe very extensively and I have never seen one single belt driven bike... I have a feeling that it'll be a long time before Europe widely adopts them :)
Does look very cool, though.
jsnell 1229 days ago [-]
+1. I've owned one in Europe for 11 years, and during that time never met anyone else who had one and very rarely even anyone who had heard of them.
But a Rohloff + a carbon fibre belt is an absolutely dreamy combination for anybody who prioritizies reliability. I'd buy a new one in a heartbeat if my current bike got stolen.
Aaargh20318 1229 days ago [-]
I’m Dutch and have a belt drive on my e-bike. They are mostly used on high-end (read: expensive) bikes.
Great system though, completely silent.
pierot 1229 days ago [-]
Oh, but you can see those from time to time Belgium. Largely adopted? No, not at all.
pandemic_region 1229 days ago [-]
Cube has one https://www.cube.eu/en/2020/bikes/urban/hyde/cube-hyde-pro-b... , I bought the 2018 model it's really nice and convenient to drive. Going back to traditional chain once you drove one of these may be similar to automatic vs manual gear shift in a car, why would you? Note: I'm a casual cyclist.
scns 1228 days ago [-]
Nice one, thank you. Love the 2021 models colours.
simooooo 1229 days ago [-]
Nicolai make some nice ones
FpUser 1229 days ago [-]
I've seen quite a few of those here in Toronto. One owner I've spoken to actually said that it has noticeably higher friction. I did not try those bikes myself so can not really confirm/deny.
jiofih 1229 days ago [-]
It has higher friction at low speeds, but has better power transfer than a chain once up to speed.
danishdev 1229 days ago [-]
"Largely adopted" also avid cyclist both in the city and in the countryside, and I don't recall seeing one of these ever
usrusr 1229 days ago [-]
I've seen many, but only in shops. On the road they just don't look that much different, they are the kind of bicycle that doesn't draw any attention and you surely won't see any parked because they are way out of street parking price range anyways (particularly in the Netherlands were most bikes don't even cost as much as the belt itself because returning home on foot isn't much fun)
1229 days ago [-]
GhostVII 1229 days ago [-]
If you want to shift gears using the carbon drive you have to use an internal gear hub, which has a lot less range than a traditional derailleur and is less efficient. So if you are riding a racing or mountain bike a chain system is probably a better way to go.
Also it looks like you can't shift under load with the internal hubs which is a problem if you are trying to climb hills quickly.
kleer001 1229 days ago [-]
> a lot less range
Maybe in the more popular implementations like from Shimano. But there's internal hubs with greater ratio spread than chained: The Rohloff:
...which at ~€1100 costs more than many people will spend on a bike, weighs more than a full set of sprockets and a derailleur, is less efficient due to the staged planetary drive, can only be repaired by sending it back to the factory, can (like other planetary drives) not be shifted under load and as such is more of an interesting novelty than a real solution to the stated problem.
brudgers 1229 days ago [-]
All the gears on an internal hub are usable, there's no overlap. These days the ubiquitous Shimano Nexus hubs can shift under load. For the kind of bicycle most people buy they are a reasonable alternative because there isn't a fragile derailer, there's no double shifting, and the adjustment is static alignment of two yellow marks.
In terms of friction, there are no jockey wheels and the chainline can be perfectly straight. Anyway, the internal friction of a geared hub is going to be unnoticeable for an average cyclist because the tires will be under-inflated, the chain covered in crud, and the brakes will be rubbing on untrue wheels.
But like everything it's a tradeoff.
filmor 1229 days ago [-]
Good internal hub gears can be shifted under load, and the Rohloff one is probably as good as it gets.
klyrs 1229 days ago [-]
I ride a Rohloff and you do not shift them under load. Most of the shifts will tolerate a light load, but going from 7-8 while steaming up a hill will immediately bind the gears and you need to backpedal a few teeth to get it unstuck. By the time that's all sorted, you've lost your momentum and need to downshift again, not to mention taken months off of the lifetime of your very expensive hardware. As you can probably tell from my description, this is a mistake I've made. Binding up your brand new $1500 transmission is a great lesson to never do that again.
Yetanfou 1229 days ago [-]
The Rohloff can not be shifted under load. You can shift by quickly letting off power, shift and then resume like you can do with other planetary gear systems.
Here's a discussion on the subject of shifting under load, with opinions from "both" sides:
You can't/shouldn't shift under load with a derailleur either. Pinion gearbox has an option of 18 gears with a 600%+ ratio while something like SRAM Eagle 1x12 has 500% ratio. I don't know about the efficiency but i think something like this should be the future - https://www.pinkbike.com/news/allen-millyard-part-1-2008.htm... or maybe there is proper reason why nothing like this has come into the market - shifting without pedalling or under load, closed system (don't care about dirt/water) and no noise.
brudgers 1229 days ago [-]
My previous bike had a Shimano Nexus 8 speed. It would shift just fine under load. My current bike has a Sturmy Archer 3 speed and doesn't.
Geared hubs are great for riding in traffic because you can shift while stopped. Pulling harder with traffic up to a light and braking aggressively, and switching to the right gear while waiting for the light to change.
Like everything it's a tradeoff. For me, geared hubs make a bicycle a more useful tool. Less fragile. Less maintenance. Idiot friendly static adjustment.
jacquesm 1228 days ago [-]
8 speed is a bit delicate to shift under load, if you plan on doing that a lot a 5 speed would be a better choice (also better for e-bikes, it will deal much better with the torque).
brudgers 1228 days ago [-]
The older I get, the more willing I am to use tools and accept that it will eventually wear it out. I put about a thousand miles around town in a year on it. The whole bike was $500 new with shipping. Never destined an heirloom.
The Nexus eight speed is the seven speed with a “granny” gear. The seven high gears have small steps relative to a five or three speed. I suspect this might make shifting under load less stressful on the components...note that under load shifts are always just one gear at a time unlike a derailer.
The Nexus 8 is a great piece of kit. Robust, inexpensive and stupid easy to tune.
pkulak 1229 days ago [-]
My Pinion gearbox has 12 gears and a 600% range; about as much as a 3-chainring derailleur system. You can get them up to 18 gears and over 636%.
It is less efficient (apparently). But at least it's consistent. Ride a chain in the rain for just a couple days and trust me, it's nowhere near that theoretical 95%.
frabbit 1229 days ago [-]
Depends on the IGH. Nuvinci and Schlumpf definitely can.
The efficiency (like all other marginal gains in cycling) is important for racers or long-distance tourers. For everyone else it needs to be considered against the maintenance burden required to maintain an exposed drivetrain which needs to be cleaned, lubricated and adjusted in order to maintain its relative efficiency.
And weight...
danburbridge 1229 days ago [-]
Gates only quote between 95-98% efficiency. You can relatively easily get to 98% with conventional chains using wax and oversizing chainrings and sprockets and you don't need to worry about splitting your frame to replace them...
This is a very niche product but sounds like an interesting approach. The users of it likely won't care if it needs replacing every ride if it means saving watts and winning (olympic) races.
cptskippy 1229 days ago [-]
> Europe has largely adopted it
I'm not sure you're using the term "largely adopted" correctly. It implies that something is the majority or norm, not a rare occurrence.
rconti 1229 days ago [-]
I've got a belt-drive "commuter bike" that doesn't get ridden much these days. It currently has a Gates Carbon Drive which I mostly like, and you're mostly correct. But it came with a Continental belt drive system that was awful. I snapped my first belt on it under load when it was about 6 months old. The damn thing always squeaked no matter how clean i tried to keep it. The rear wheel had to be on perfectly straight or sometimes the belt would slip one way or the other -- and of course, belt tension is very hard to get right. I think the gates system operates at lower tension than my continental did, which is a plus.
I hope the Gates belt is stronger than the Continental one, but I don't know for sure.
I think Ghost ultimately was willing to goodwill replace the continental trash with a complete Gates drive system because a continental belt could not be sourced anymore. But, I still have to worry about the nightmare of axle nuts, belt tension, removing the tiny nut from the hub to disconnect the shifting, and removing the brake caliper (!!!) to fix a flat.
8note 1228 days ago [-]
Sounds like your next thing is to switch to tubeless tires so you don't have to do that so often
Yetanfou 1229 days ago [-]
I've destroyed a number of Sturmey Archer planetary drive clutches - the square cross-shaped bit which transfers force from the sprocket holder to the drive - by just using them, leaving me wary of planetary drives. While I've also gone through derailleurs they do seem to handle power better than planetary drives and have the additional advantage of feeling far more like a direct drive. One of the advantages of a bicycle is its simplicity, there is not much between your feet and whatever goes for road you happen to be on. I'll gladly give up 2% of efficiency to keep the system simple, repairable with off-the-shelf parts which can be found anywhere in the world and affordable.
analog31 1229 days ago [-]
Then you're a stronger cyclist than me, because I've ridden S-A AW hubs for decades and have broken Zero of them. I've have had them open to determine that they tend to stay in pristine condition under normal use.
But the common IGH's do come with specs for minimum gear ratio front to back (2:1, I think), suggesting an implied torque limit. I've always wondered which part was the weak link.
The cogs wear out under normal use (I've replaced a couple so far) but that's true on derailleur bikes as well.
Yetanfou 1229 days ago [-]
> I've always wondered which part was the weak link.
Well, now you know... especially in 3d gear (when the cross drives the planetary hub by engaging on the top of the cog axles) the clutch is under high load. I often rode that bike with a heavy trailer (made from a shipping crate and some moped wheels which I happened to have lying around) to haul my guitar, amp and saxophone through the Dutch countryside to practice with my band, this may have put too much of a load on the hub.
analog31 1229 days ago [-]
I'm a double bassist, and have only seen pictures of people cycling with their basses, but they are all either from the Netherlands or NYC.
alistairSH 1229 days ago [-]
How do you handle gears with the belt? Most of the bike I've seen in the US that use the system are single-speeds. I suppose you could use a internally-geared hub, but a Rohloff is mega-expensive and the Shimano offerings leave a lot to be desired.
wishinghand 1229 days ago [-]
I bought a Spot Ajax with an Alfine 11 speed hub. Shifts well and has a good spread. I’m a recreational bicyclist though, I have no idea how it “performs”.
alistairSH 1228 days ago [-]
For recreation/commuting/city use, the Alfine is fine. Unless Shimano has revamped it in the last few years, it isn't particularly robust and doesn't work well for high-power use (mountain biking, in particular).
1227 days ago [-]
kevin_thibedeau 1228 days ago [-]
They're going onto e-bikes that will never be pedaled under human power.
Finnucane 1229 days ago [-]
The advantage here is that the chain could be made backwards-compatible with existing conventional drivetrains. The Gates drive can't be retrofitted onto older frames.
Sunspark 1229 days ago [-]
Why can't it be? My bike is a fixed gear track frame. If the threads of the sprockets are compatible with the rear wheel, then it should be able to fit.
Tomte 1229 days ago [-]
The belt is a closed loop and under high tension when installed. Your frame needs to be able to be opened to let the belt in, then your sprocket pack needs to be able to move backwards, so you can put tension on it.
tigerBL00D 1229 days ago [-]
> then your sprocket pack needs to be able to move backwards, so you can put tension on it
I am assuming that's what the poster meant by putting emphasis on his frame being a fixed gear one. Those normally have horizontal dropouts to put tension in the chain.
davidgould 1227 days ago [-]
But they don’t have split frames so there is no way to install the belt in the first place.
Tomte 1229 days ago [-]
Thanks, I had no idea!
usrusr 1229 days ago [-]
Unlike a chain the belt is a closed loop, you can only use it with a frame that can be opened in the rear triangle.
turbinerneiter 1229 days ago [-]
There is however a belt drive systm with a split belt. Seems to be quite new and expensive and propably come switch its own upsides and downsides.
toxik 1229 days ago [-]
I have seen maybe one driveshaft based bike, and I’m European, and that was at the school of mechanical engineering.
scns 1228 days ago [-]
There was/is? a danish company building those, seems they switched to belts though.
uoaei 1229 days ago [-]
It is a belt drive system, not a driveshaft-based system.
shirakawasuna 1229 days ago [-]
Any idea of the sustainability of the Gates Carbon Drive system? Looks like it's made of polymer + carbon fiber. On the other hand, traditional chains eat+shed oil and grease.
robga 1229 days ago [-]
My Gates carbon belt is like new after 8 years riding my Schindelhauer Siegfried. I seem to remember 10 years quoted when I bought it.
I disagree both about the adoption rate and the superiority of the tech. It only works if the frame can be opened up and this means the whole bike has to be designed around the belt drive system. It's a slow thing to do and quite expensive, whereas replacing a regular chain takes less than five minutes (it's a bit more messy though).
mauvehaus 1229 days ago [-]
I have to be honest, when IKEA launched the Sladda, I had high hope that they'd sell a zillion of them so I could pick one up barely used for a pittance in a couple years. Sadly, that seems to have not happened, and we'll have to wait a bit longer for the belt drive to become commonplace :-(
usr1106 1229 days ago [-]
Wasn't that the one subject of a recall because the belt could break? Recall for refund, not for repair. So a complete failure.
mauvehaus 1228 days ago [-]
Ugh. I missed that. Bummer!
I wonder if the frame wasn't built to allow belt replacement?
gerbler 1228 days ago [-]
I have a Gates Carbon drive too. It's extremely convenient, but my understanding is that it's lower efficiency compared to a well-mantained chain. Due to the practical challenges of maintaining a steel chain, I think Gates does well and it's a great commuter option.
lqet 1229 days ago [-]
> Europe has largely adopted it
I live in a very bike-friendly European town. I use my bike daily. I have seen maybe 10 if these things in the last 3 years, mostly owned by elderly people who were sold high-end e-bikes they don't need.
Some cyclists are indoctrinated to the point that they might actually buy this insanity.
rorykoehler 1228 days ago [-]
HN is becoming more conservative by the day. Shouldn’t companies/people be applauded for thinking outside of the box and trying to innovate?
Kliment 1228 days ago [-]
Innovation can be good, scamming other people into spending money on things that don't work, not so much. There's a whole lot of the latter masquerading as the former. There's also a whole lot of user/customer/community hostile innovation, like the entire advertising industry.
rorykoehler 1228 days ago [-]
That’s not the case here though. The design I linked is a legitimate attempt at solving a real problem. Whether it works as well as intended or not is a separate issue.
FpUser 1228 days ago [-]
The design as plain obviously wrong. The only "legitimate" part there is trying to part people with their money for zero benefits.
rorykoehler 1227 days ago [-]
I'm not a mechanical engineer or anything remotely like it. Can you explain why the design is wrong and especially explain why you think it's a dead end that can't solve it's problems via iterating?
FpUser 1227 days ago [-]
This drive train simply can not handle high torque as the chainrings will bend under load. They admit it themselves. Increasing their thickness will cause a whole lot of compatibility problems and also turn the whole thing into a monster.
This expensive ceramic bearings are exposed and will experience significant wear. Properly insulating them would wipe out whatever miniscule gain in efficiency they claim as the insulation increases losses.
Finally reducing chain friction (which is already very low on a tuned drivetrain) to some fraction (that has yet to be proven for real conditions) is tantamount to snake oil in my opinion.
These are just few. I could go on but it is not worthy the typing and mental efforts.
jiofih 1229 days ago [-]
As a counterpoint to all the other comments: EU, my electric bike has a belt. Most high end electrics do. Might not be the same outside of the cycle countries (nl, dk...).
enriquto 1228 days ago [-]
> Europe has largely adopted it,
I'm an avid leerer of other's bikes, and in my long and fruitful bike leering career in Europe, I have seen just one (1) gates drive.
layoutIfNeeded 1229 days ago [-]
>Europe has largely adopted it
I'm a European cyclist and only ever seen conventional chains.
gameswithgo 1229 days ago [-]
not as efficient though
forest_dweller 1229 days ago [-]
Every so many years I see a post like this where they claim to have improved the drive chain of bicycles and they really never go anywhere, mainly because they aren't compatible with other kit.
I've built and repaired quite a few push bikes over the years I am still using fairly standard shimano kit. The problem with exotic equipment is that even decent shops might not be able to repair it and it normally requires specialised tools.
I mucked about with Campag and some other exotic kit and it is always a PITA as you always have to go hunting around for parts of ebay after a few years because threads and tapers on things like bottome brackets aren't compatible.
FridgeSeal 1229 days ago [-]
As a mountain biker primarily, chasing marginal gains on chain improvements seems strange to me.
Chains are a wear item, and small gains in the efficiency are going to be lost pretty quickly after the first few times it’s been ground through mud, sand and grit, which will take all of one ride.
matthewowen 1228 days ago [-]
This is being marketed to track cyclists who have none of those issues.
More generally, novel drivetrain products often seem to take off early in the tt/tri world which also don't really have to deal with those issues.
It's also worth noting that anything that all else being equal, improved efficiency goes hand in hand with better longevity. As an example, applying a hot chain wax is a winner in terms of watts, but it's also cheaper in the long run.
emcq 1228 days ago [-]
You can't really make all things be equal and get increased efficiency and longetivity for most cases.
The trade-off are explicitly made to have reduced longevity to have better efficiency.
Take tires for example. A low rolling resistance lightweight XC tire will have significant advantages over a dual casing 2.6" DH tire. The XC tire will smoke a DH tire but not have better longevity on dirt. The XC tire will be slower on some DH tracks and the DH will be slower on XC. If you ride a DH tire on a road it will ironically wear down more quickly than a typical XC tire, and you can shred an XC tire in one day on technical DH.
matthewowen 1228 days ago [-]
I was speaking specifically about drivetrains.
Tyres generally trade traction off against longevity, plus, yes, specialization is a big consideration.
jl2718 1228 days ago [-]
This makes me think about removing every other sprocket tooth and then milling down the attack angle on the forward side so that the two rollers would both seat on either side of one tooth. I think the point of this design is that the link transfers compressive force forward as pressure if both sides are engaged.
The loss in a chain is nearly all in the roller as it engages with the first tooth in the front chain ring. Most of the force is being transferred from this first tooth, and it presses directly on the roller, which is also rolling into its seat position on the tooth. So a better design would have the roller get seated on the teeth before the force gets transferred to it, and then have no rolling until force transfer is done, then roll off gently.
A new chain on a new chainring engages at the bottom of the tooth, right where it seats, and the torque of the chain ring rolls it up the forward tooth ramp until the tangential component of the force pressing into the contact point equals the pedal force. This happens on all points engaged on the sprocket. So you get a lot of rolling, but that’s over a lot of rollers. As the chain wears, it gets longer, so the teeth catch early from the tip, and it rolls all the way down the tooth while the entire chain tension is all on that first roller.
This particular design has no rollers at all. It will still stretch because it has the same pin-plate interface, and it seems that a modest stretch may render it inoperable, but I’m not sure.
Theodores 1229 days ago [-]
This chain is a nice idea but a solution in search of a problem. Right now it is track bike and e-bike only, so not even for hub gears.
The track market is miniscule and we'll catered for. Then the e-bike market does not need a 2 percent gain in chain performance.
The enemy of the chain is dirt. Real world cycling in the 1950s had hub gears and a big case to keep the dirt out. Then derailleur gears aimed at the sports market dropped the chain case. This made sense for cyclists with a team car behind them.
brudgers 1229 days ago [-]
Reduced chain width has significantly changed bicycle drive trains over recent decades. Bicycles have many more usable gears. A manufacturer who pushed a non-standard chain heavily would wound cycle shops. Standardization facilities keeping parts in stock.
alistairSH 1229 days ago [-]
I'm not sure that's true.
SRAM already went with their own non-compatible design with their latest road groups (AXS road). Bottom bracket "standards" have proliferated over the last 20 years (all 8 of the bikes in my garage use a different system). Hub spacing is non-standard too (100mm/130mm QR, 100/135 QR, 100/135 TA, 100/142 TA, 110/148 TA, Superboost, DH, and a few other niche standards). Even within a brand, there's no guarantee shifters and detailers are compatible.
Basically, the industry has "standards" but only keeps them long enough to develop the next. Gotta keep us buying $5000+ bicycles somehow.
loeg 1228 days ago [-]
The threaded BSA BB has been standard for low-middle end bikes for a long time. Sure there have been a lot of different kinds of pressfit shell, but I would avoid them all except BB86/92 (Shimano).
Hub spacing in QR is standard at 100/130 for road, 100/135 for mountain. Thru-axle is somewhat new and I think we'll standardize on fewer than that eventually. I think some of those are a lot more popular than the others.
brudgers 1229 days ago [-]
I'll cop to $5000 bicycle unfamiliarity and preferring to own one bike at a time. I guess the era of standardized chains is past. So I stand corrected. Thanks.
My current bike a late model Brompton, I am familiar with the extents to which other bespoke components is possible and a deliberate choice over something by Bike Friday.
loeg 1228 days ago [-]
Chains at the same nominal width (e.g., "11 speed") are approximately compatible (Shimano/SRAM).
rconti 1229 days ago [-]
They're standard-ish. My road bike and mountain bike are both 12 years old, which means I've learned the ins and outs. SRAM likes to abandon old derailleur tech, but SRAM and shimano chain spacing are MOSTLY similar. On road bikes, the Shimano 9/10spd are the same, if I remember correctly. I think the 11 and 12 speed stuff use narrower chains, BUT conveniently front chainring spacing seems to not matter a whole lot. 10 speed ultegra chains and cassettes work fine with an "11 speed" generation front crank, thankfully.
ip26 1229 days ago [-]
It's true that bikes are a pretty sad story when it comes to standards. I think axles is going to settle down soon though. QR seems to be on the way out and standard TA for road with boost TA for mountain seems like the direction we are headed...
(Disc brakes in particular are not a good match for QR)
alistairSH 1228 days ago [-]
Trek is already moving to SuperBoost on their trail bikes. This appears to be DH width, but retaining the 12mm/15mm axles (vs thicker used in DH).
It's a mess. And really annoying for anybody who breaks parts a lot - while almost everything is still available in some form, the newest best stuff is often only available in the latest standards.
1229 days ago [-]
loeg 1228 days ago [-]
Incompatible chains and parts harm end-users, too.
kenned3 1229 days ago [-]
Whenever i see things like this, i immediatly think "Audiophile". you know, the $238 "Directionally balanced" Ethernet cables, or the "low oxygen" copper.
Once people take their hobby too far, you will end up with things like this.
For $2K you can buy our (exotic and unnecessarily expensive metal) chain, which reduces friction to 0 and lasts forever.
I ride a fair amount (150-200KM a week in the summers) and am always surprized to see everything on a bike is measured in grams, except the biggest impact, the rider itself?
Sure i shaved 4g on my $400 waterbottle holder.... but when i weight 80KG.. and have another 2kg of water with me, does that 4g really matter?
loeg 1228 days ago [-]
This is more like "random concept car" / F1 than audiophilia.
The idea here, if it is sound and measures well, is basically only useful to track racers (because they race single-speed bicycles). Current chains are extremely efficient, and mostly compatible at the same nominal width (expressed as 10-speed, 11-speed, 12-speed). And they are very cheap. People do spend absurd money shaving grams on bikes, but this product is not really in that space. It requires an IGH or a single-speed and isn't compatible with any other high-end drivetrain components on the market. That's a non-starter even for the people spending $15k on a bicycle.
Here's a better "audiophile" example in vogue in cycling at the moment: ceramic bearings. These cost a lot more than high-quality steel bearings and quickly become less efficient than steel ones because the hard ceramic bearing destroys the softer steel races.
kevin_thibedeau 1228 days ago [-]
It can also have industrial applications if their claims are true. That's a bigger market than a single bicycling niche.
iambateman 1229 days ago [-]
It’s not odd for a professional rider to optimize to that level, though.
The article spent most of the words focused on high-performance racing.
lanius 1228 days ago [-]
>Sure i shaved 4g on my $400 waterbottle holder.... but when i weight 80KG.. and have another 2kg of water with me, does that 4g really matter?
Plus don't cycling competitions set a minimum bike weight anyways?
1228 days ago [-]
KSteffensen 1228 days ago [-]
It requires less effort to buy a $400 waterbottle holder than to change your diet to loose a couple of kilos.
And you can show off gear, you can't show off weight loss.
patrec 1228 days ago [-]
Not being overweight is nowadays a prime status marker, so you can absolutely show it off! Once you start shaving off 4g at a time, it's probably time to switch to gear though.
at-fates-hands 1229 days ago [-]
Side note:
I used to work in a bike shop for about ten years. One time had a guy come in who worked with Kyronics. We all made jokes about freezing dead people - but he said you can apply Kryonics to a wide array of stuff not just dead people.
One of the many things some of the team riders were seriously considering was having their cranks, chains and frames frozen since its supposed to alter the molecular structure to make them stiffer and more durable.
I'm not sure they did it, but it was a topic of constant conversation for weeks afterwards.
Cryogenically freezing auto brake rotors has been a thing for awhile, but I forgot about it until you mentioned it here. It's probably fallen out of favor as I don't hear much about it. But the claims may well be true. On the other hand, when I only replace brake rotors every 60-80k miles, I don't much care.
Unless I'm mistaken, the efficiency gain is from shortening the length of the pivoting pins to just what's required for connecting the conventional outside chain links to the saddles.
In a conventional chain the pins cross the sprocket teeth and must rotate across that entire width; more frictional loss.
In this design the saddle seats on the tooth, and just the relatively short pins linking the saddle to the outside chain must pivot.
kazinator 1229 days ago [-]
> They’re soon going to be used in top-tier UCI track races.
And that is where this monstrosity will stay, until they find a way to fit it into a 6 speed derailleur system to make it viable for $60 bikes sold in Walmart, and eventually an 11 speed derailleur system.
mikewarot 1228 days ago [-]
Chains stretch, thus any sprocket system will inevitably end up concentrating the load on the last link or two of contact.
There are systems that actually could produce less friction, however they can't handle ANY contamination, thus ruling them out.
Your best bet is to look elsewhere. I would try reducing the contact friction as the links engage. To do this, I would recommend using BAM coatings on the chain and sprockets. It has lower friction than Teflon, AND is almost as hard as diamond.
>"This isn’t just some lab experiment, either. They’re soon going to be used in top-tier UCI track races."
As long as it is not an absolute crap pros would use whatever equipment their sponsor tells them to use. Chain durability for pros does not matter and whatever the difference in friction are really negligible.
>"ability to transfer 25% more Torque"
Any decent chain will handle way more torque than cyclist can deliver so what's the point.
>“four times increase in system lifetime”
I believe it when I see it. Also how much more this puppy gonna cost and cyclists would need to change chainrings and sprockets. This much troubles for the sake of chain? Sorry but I have my doubts.
jandrese 1229 days ago [-]
How well can these handle dirt and debris? It looks like a high precision connection which makes me slightly worried that an errant grain of sand or just an accumulation of road grime might jam up the works.
petre 1229 days ago [-]
People concerned with dirt do not concern themselves with chain efficiency but rather stuff that removes dirt.
ruined 1229 days ago [-]
reliability in adverse conditions is an important facet of any design. nobody cares about a new hyperefficient vehicle if it has to operate in a vacuum
usrusr 1229 days ago [-]
This design is specifically aimed at track cycling which is as close to vacuum conditions as you can get if you intend to run the rider on ambient oxidizer.
loeg 1228 days ago [-]
This design is made for vacuums. Really. Once your chain is dirty, you're well below the 98% efficiency figure they're competing against.
Lerc 1229 days ago [-]
People keep telling Elon Musk that.
Cactus2018 1229 days ago [-]
Gears! - But Were Afraid To Ask (MiniLathe) - This Old Tony
Great channel about machining stuff with mills, lathes etc. with some comedy mixed in while also being very informative.
Also I found that watching machining of all kinds of stuff is strangely relaxing to me.
colechristensen 1229 days ago [-]
Reading through there is something very noticeably absent: any claims of increased efficiency.
If you spread pressure out offer wider areas, you don’t get less overall friction at least in the first order approximation of friction you find in first year physics.
What it looks like is an attempt to make something better that improves metrics which aren’t necessarily coupled to better overall performance.
CalChris 1229 days ago [-]
First paragraph of the article:
UK company New Motion Labs has introduced a completely different design that not only promises *better efficiency*, but also decreased wear throughout the entire drivetrain, and all without the need for laborious cleaning and lubrication procedures.
The article also puts an upper bound on its claim of 2% since conventional chains are already 98% efficient.
It will require new chainrings and cassettes (probably RD rollers as well).
colechristensen 1229 days ago [-]
Yes, but for other claims they have quotes and numbers, when it comes to presumably the most important, there’s nothing.
carlob 1229 days ago [-]
Given a conventional chain can be up to 98% efficient then the maximum increase in efficiency is 1/.98 - 1 = 2.04%
colechristensen 1229 days ago [-]
A percentage of a percentage is an odd way to express a change, and at that picking the non-loss side as basis.
One could say increasing efficiency by 1% equivalent to reducing existing losses by 50%, both of those are reasonable bases, making it a percentage of the existing efficiency feels off.
carlob 1228 days ago [-]
I disagree: my basis makes it easier to answer the question of how much faster can you go by exerting the same power. The point being that when you are already close to maximal efficiency the gains are very marginal.
buzzerbetrayed 1229 days ago [-]
Is 100% efficiency physically possible? Or are they just trying to get as close as they can, knowing they can never truly reach 100%?
yoz-y 1229 days ago [-]
Wouldn’t a vélocipède be 100% efficient (in transferring motion of legs into motion of the wheel)?
robotresearcher 1229 days ago [-]
Never 100%. Friction anywhere will prevent perfect efficiency. Also any compression, flexing or twisting of the components, which can be very, very small for hard steel at these low forces but not quite zero.
wishinghand 1229 days ago [-]
As long as there is friction, no.
invernomut0 1229 days ago [-]
How does it compare with the rohloff system?
Anyways it seems to be significantly more expensive thus I don't think it will become widespread.
EarthIsHome 1229 days ago [-]
I enjoy the rohloff system. I use it with the gates centertrack belt drive instead of a chain.
The rohloff system is quite heavy though, so I don't know if it's "more efficient" than a traditional high end sprocket-and-chain system. The rohloff also shifts the weight to the rear of the bike. Maybe the pinion gear box system might be better since its weight is low and towards the center of the bike.
petre 1229 days ago [-]
It's not more efficient than a clean derailleur transmission but less maintenance. The trouble with derailleurs is dirt.
leoh 1229 days ago [-]
You are not referring to rohloff, but the gates carbon drive, which is amazing technology. Rohloff works with either a chain or a belt.
vondur 1229 days ago [-]
I sure hope it's cheaper than the Rohloff hub, I can't imagine anyone buying these if they are very expensive. I thought I had read that chains and sprockets were pretty efficeint in terms of energy loss.
leoh 1229 days ago [-]
It's the chain not the internal hub. Rohloff can use either a chain or a belt drive. The belt drive is cheap, and works with other internal hubs (sealed planetary gear system), which are much cheaper (e.g. Shimano, others make them).
petre 1229 days ago [-]
Tourers buy them. Money well spent. Just change the oil every year. Less efficient than a clean deraileur drivetrain but those stay clean for about 30 minutes.
mauvehaus 1229 days ago [-]
Even a muddy chain is unreasonably efficient, to the tune of maybe 85-90% [0].
Having bike toured, keeping a chain halfway clean (or at least not muddy) is not hard. Yes, I see the appeal of an internally geared hub, but marginal differences in efficiency either way would not be high on my list of concerns.
Apparently well adjusted modern gear can be 98% efficient.
fabianhjr 1229 days ago [-]
That is mentioned in the article:
> All of that is working, too, with independent tests showing properly race-prepped drivetrains to be as much as 98% efficient.
> That elusive 2%
> As good as chain optimization has become, there comes a point where there’s no more optimizing left to do, and there are no other options but to rethink the system.
Though, not as in any modern drivetrain but high-end competition drivetrains. At least I imagine it would be with really expensive solutions like Ceramic Speed bearings everywhere.
Someone 1229 days ago [-]
This is a chain system, to transfer power from the bottom bracket to the wheel. AFAIK, Rohloff is gear system built inside a wheel hub. How would one compare those?
stunt 1229 days ago [-]
You are right. Perhaps he meant if it can be used with the Rohloff system or not.
It can be used with the Rohloff system. But, I think you need a compatible chain ring since they are talking about a new tooth design requirements. The Rohloff system has the chain ring attached to the hub gear. So you presumably have to change that chain ring yourself.
ggm 1229 days ago [-]
Tolerance high need. Stretch or fracture.. no longer optimal. Current chains.. been working for over a hundred and fifty years and we all know how to fix em and oil em. So for the 2% improvement hero, sure. For me? Less sure. (I ride a clunker i put a Brookes leather saddle on, now it fits my bum cheeks I'm good)
vaccinator 1229 days ago [-]
it does look more durable with all the the added metal but how could that make it faster? but either way, I never had durability issues with my bike chains (including motorcycles), specially when you can adjust for "stretching"
SirZimzim 1229 days ago [-]
Higher efficiency means more power from the cranks is going to the wheels. But this looks like something primarily for high power situations right now where those tiny gains matter more. Durability wise it will be great for ebikes as they eat up drive trains more so this should reduce cost of ownership in the long term.
stiray 1229 days ago [-]
As a guy who ignored the chain on his first bike with XTR gears and had to replace whole drivetrain - yep, I would buy this chain. No question asked, as long as they guarantee me that it wont be stretched.
usrusr 1229 days ago [-]
Just accept that chains are the consumable #1 for a bike and be happy. Shimano chains are absurdly cheap anyways.
alistairSH 1229 days ago [-]
This. On a mountain bike, replace the chain every 50 hours of use, or annually and the rest of the drivetrain will last for years.
Or, if you're dumb and lazy (me!), ride the whole lot into the ground and replace the whole bike every few years because #shinynewtoy!
frabbit 1229 days ago [-]
50 hours of use
I assume this is a typo for 500?
usrusr 1229 days ago [-]
500 would be 5000 km even at just 10 km/h which would be generous (but doable) for a Shimano chain even under roadbike conditions (where this would be roughly 200 hours). Mountain bike conditions will increase wear level a lot and they'll probably be a bit faster than 10 km/h as well. I don't know if it is really as bad 50h, but I've stopped mountainbiking when suspension forks ceased to be exotic. It also differs regionally: riding muddy in a place where the air is full of corrosive ocean spray will require far more chain replacement than riding in the Utah rock deserts.
If you ride a chain until it stops working you'll probably reach those numbers. But then you will have to replace the entire drive train which is far more expensive. The chain is the cheapest part and replacing the chain a bit earlier than absolutely necessary will greatly increase the durability of more expensive parts. As a little bonus you'll repeatedly get the joy of riding a new chain. Replacing at the right time is cheaper and more enjoyable at the same time.
alistairSH 1228 days ago [-]
No, not a typo. 50 hours for expendables and suspension service on a mountain bike (I'm assuming it's actually used as a mountain bike).
For, me that works out to 2x season. The cassettes are $300 and the chains are $40. So, the chains are treated as 100% consumable/disposable.
frabbit 1228 days ago [-]
Interesting. Makes sense now that you and others have ball-parked it.
emcq 1228 days ago [-]
A better rule of thumb is miles because hours don't reflect the amount of energy put into your drive train.
Typical recommendations are every 500-750miles for a mountain bike. For the average mountain biker I think that would be more like every 125 hours at 6 mph. Mountain bike chains see much more abuse than road, and you can go further too.
You can be more scientific by using a chain ware tool to measure how much stretch there is.
alistairSH 1228 days ago [-]
Either way, 50 hours = 500-600 miles for me, so we're using a similar interval.
Suspension service intervals are specified in hours, so I use the same for the rest of the bike.
canofbars 1229 days ago [-]
Also replace them before they are fucked. Get a chain measuring tool and when they get half way worn just get a new chain. If you wait too late you fuck the gears and those cost way more to replace.
throwaway189262 1228 days ago [-]
Chain wear is caused by bad lubrication. Both lack of lube and grit in the lube. You can use a bike chain with 25 horsepower if you put it in a sealed case half filled with oil.
CalChris 1229 days ago [-]
There is an easy and straightforward way to make this chain successful. Put in on a team bike that wins. 2% is quite a bit in a peloton. 2% of 2% is Biopace.
bagacrap 1229 days ago [-]
it's only for single speed drivetrains
CalChris 1229 days ago [-]
Yes, all of their examples are single speed but I can't find anything in the article or site that specifically says that. Moreover, in their competitive critique of belt drives they complain that belt drives can’t be used with derailleur gears.
Still, single speed. Get on the podium with track racers.
BTW, my skepticism is very tempered. I still think Biopace was a good idea and could be made to work. I think this is a good idea and I still think it could work. But it has to, you know, work. It has to demonstrate and provide that efficiency rather than just claim it because modern chains are pretty darned good.
supernova87a 1229 days ago [-]
Trucks use a solid driveshaft to transmit power to the rear axle. Is there any merit to using that idea for bikes? (with a geared transmission?)
It's been done. It didn't take off mostly. Some combination of too heavy or too inefficient or too expensive.
matsemann 1229 days ago [-]
How is the shifting? Sounds a bit too rigid. Smooth shifting is probably more important for performance than those last promilles.
analog31 1229 days ago [-]
There's no shifting. These chains are for single speed drivetrains, e.g., track bikes, but also possibly single speed freehub and internal gear hub bikes. This could be one of those things that starts its life as a performance upgrade for competition use and either does or doesn't make it into the world of everyday cycling.
canofbars 1229 days ago [-]
If it can't bend you could use it with a gearbox which is how belt drive bikes work.
stjo 1228 days ago [-]
Maan I thought hn had a lot of 1M/year salary software developers, but just look at the amount of bike engineers.
fnord77 1228 days ago [-]
wish belt drives would catch on more.
(yes, I realize the frame needs to be split to remove the wheel, but in the newest designs this doesn't seem like too big a deal)
Rendered at 13:15:59 GMT+0000 (Coordinated Universal Time) with Vercel.
Conceptually, to me, the new interior bits serve as a sort of individual tooth holder that is free to rotate with the tooth as the tooth orbits the axle. So there's not much friction at the tooth:holder junction as the sprocket turns.
That friction is now occurring at the narrower intersection of a hinged tooth holder and chain link. Being a narrower hinge joint, just the length of a chain link's thickness, it has less surface area for friction, and less room for debris ingress etc.
Conventional chains rotate a pin across the sprocket's thickness, and AIUI use a roller to try keep debris out of and lubricant within that interface to reduce friction. This contraption takes it a step further.
You can actually envision the tooth holder as analogous to the roller in a conventional chain, just with less surface area at the twisting intersection. They've obsoleted the conventional roller.
Likely the "pins rubbing" you mention doesn't really matter, because the wear from inserting and removing the chain as it cycles around has to be a miniscule fraction of the wear that occurs under load.
In a worn chain, the rollers engage high up, and then work their way down (under high load) until seated at the base. In the unworn condition, engagement begins at the base of the tooth where the forces are better spread over the roller.
In point of fact, the forces are spread out over more teeth when worn. The first tooth engagement might begin 3mm high, then 2.5mm, then 2mm, etc. over ~6 teeth. Whereas the fresh chain might manage 2 or 3. But the wear and friction of the worn chain is much higher as you have a great deal of motion under high load as the loaded rollers creep down. The unworn chain has perhaps higher loads, but the roller is essentially seated and immobile at the base of the gear for this.
Not at all! The article claims 98% efficiency.
Roller chains are used to transfer torque in bicycles and motor cycles, inside internal combustion engines to drive cam shafts... and many more applications covering a huge range of power levels and environments.
Not only is it efficient, it's cheap.
If that last 2% of efficiency was important (or easy to obtain) it would have been on a GP motorcycle already.
- BMX: This market would be all over anything that would be an improvement in durability, and frankly a percentage would just do it for the different tooth design.
- Auto: Admittedly, the site for the company that is making this new chain mentions automotive in a blog post, but I don't see anything specific to an automotive product. A more durable and efficient timing chain is something I'd expect most of the automakers to care about.
https://www.bmwblog.com/2020/08/27/m-endurance-motorbike-cha...
My bike (a k75) has it and well it's pretty cool!
The solution clearly loses on weight/benefit ratio to just making a thicker chain.
However, the rule of thumb is to minimize rotational weight (e.g., wheels) due to the increase in rotational inertia. I wonder whether chain weight is similarly problematic.
https://m.youtube.com/watch?feature=youtu.be&v=0QDnUkUaQfk
It's interesting to look into what's actually scientifically supported in biking and other sports, and the implied effect sizes.
Often, races are won and lost in the final dash to the finish line, which is pretty much all about acceleration.
JK Rowling taught me that nonplussed is apparently a part of the daily vernacular in the UK.
> Note: The use of nonplussed to mean "unimpressed" is an Americanism that has become increasingly common in recent decades and now appears frequently in published writing. It apparently arose from confusion over the meaning of nonplussed in ambiguous contexts, and it continues to be widely regarded as an error.
https://www.merriam-webster.com/dictionary/nonplussed
I actively try to avoid USAmericanisms, except for "y'all". Go figure ;o)
[That last phrase is a USAmericanism, used for amusing intent.]
Rough synonyms: confounded, flummoxed, bewildered, perplexed, stunned, shocked, dumbfounded, flabbergasted, thunderstruck.
Using nonplussed to mean “unimpressed” or “apathetic” will leave listeners both unimpressed and confused.
https://www.merriam-webster.com/dictionary/nonplussed
My observation: "continues to be regarded as an error" is a bit of a "that's not how linguistics work" thing
Also note that this is only for track bikes with a perfectly straight chainline (technically speaking it would also work for internal gear hubs wish are increasingly driven by belts in the upper price range). The shifting chain that is deployed diagonally more often than straight is an entirely different beast, in theory much worse in efficiency and durability. Pretty much all practical durability limits stem from compromises done for that diagonal capability for sitting. Which basically goes ruthlessly against all mechanical engineering rules, like the old adage about how bumblebees were supposedly unable to fly. Yet even they work quite well, given that challenging background they work just awesome and track chains already work better than that.
Derailer systems only absord energy in the chain and bearings, and a well maintained system can maybe lose 1.5% of energy. Internal hub gearing can lose around 15% energy.
The shop keeper won't tell you this, he just wants to sell you a bike. If he starts talking difficult things, buyers might just go to the next shop to buy what they had already chosen.
Funny, I thought it was my three young kids that did that.
I always had a mountain bike growing up. Having now transitioned to more of a road bike, the difference in rideability is pretty stark.
I guess it could be the derailleur, but I assumed it was the tires and gearset that made it a pain to get places. I also have noticed a night and day difference when my tires are properly inflated. I just replaced the tubes and tires so maybe I'll have better luck now, but previously I needed to refill the tires basically daily to keep them in the right range.
1) using latex inner tubes. They’re lighter, but don’t hold air so well. Fine for racing, impractical for normal use
2) a slow puncture
4) badly seated valve tip (dirt?)
If you actually take a look at your derailleur system, you'll notice that a) the chain is not straight in all but a few settings, b) it has a somewhat complicated arm with an extra sprocket to keep the chain tight. And it is harder to protect it with a guard, so you end up with more dirt in the system if you use it every day.
But yes, internal hubs are heavier, generally somewhat less efficient, and better protected against the elements.
Maybe the "gripper plates" align themselves perfectly with the tooth at a time when the connection is still not under load yet? A conventional roller won't need much aligning, but it won't do that, it won't settle into place before load is applied. Friction scales with force. If that's how they teased out a minor delta then it's truly very clever (but likely still highly impractical outside the laboratory/indoor track setting)
[1] idea came while taking a shower, were else. Shower after churning that old Campag 12s chain a little, unfortunately only on Zwift these days
> The future apparently isn’t far away, as New Motion Labs has developed a new Dual Engagement chain that is supposedly able to transfer high power on both sides of the tooth, over nearly all the teeth available to the chain.
Yeah, I'm also wondering about how much energy it takes to "lock it in place", and then, of course, unlock it.
I've been a cyclist for 30 years now, and there's always been a steady stream of 'amazing! revolutionary!' things like this, but mostly it's incremental improvements. If it pans out, great, if not, c'est la vie.
Does look very cool, though.
But a Rohloff + a carbon fibre belt is an absolutely dreamy combination for anybody who prioritizies reliability. I'd buy a new one in a heartbeat if my current bike got stolen.
Great system though, completely silent.
Also it looks like you can't shift under load with the internal hubs which is a problem if you are trying to climb hills quickly.
Maybe in the more popular implementations like from Shimano. But there's internal hubs with greater ratio spread than chained: The Rohloff:
https://www.sheldonbrown.com/internal-gears.html
In terms of friction, there are no jockey wheels and the chainline can be perfectly straight. Anyway, the internal friction of a geared hub is going to be unnoticeable for an average cyclist because the tires will be under-inflated, the chain covered in crud, and the brakes will be rubbing on untrue wheels.
But like everything it's a tradeoff.
Here's a discussion on the subject of shifting under load, with opinions from "both" sides:
http://thorncyclesforum.co.uk/index.php?topic=4172.0
Geared hubs are great for riding in traffic because you can shift while stopped. Pulling harder with traffic up to a light and braking aggressively, and switching to the right gear while waiting for the light to change.
Like everything it's a tradeoff. For me, geared hubs make a bicycle a more useful tool. Less fragile. Less maintenance. Idiot friendly static adjustment.
The Nexus eight speed is the seven speed with a “granny” gear. The seven high gears have small steps relative to a five or three speed. I suspect this might make shifting under load less stressful on the components...note that under load shifts are always just one gear at a time unlike a derailer.
The Nexus 8 is a great piece of kit. Robust, inexpensive and stupid easy to tune.
It is less efficient (apparently). But at least it's consistent. Ride a chain in the rain for just a couple days and trust me, it's nowhere near that theoretical 95%.
The efficiency (like all other marginal gains in cycling) is important for racers or long-distance tourers. For everyone else it needs to be considered against the maintenance burden required to maintain an exposed drivetrain which needs to be cleaned, lubricated and adjusted in order to maintain its relative efficiency.
And weight...
This is a very niche product but sounds like an interesting approach. The users of it likely won't care if it needs replacing every ride if it means saving watts and winning (olympic) races.
I'm not sure you're using the term "largely adopted" correctly. It implies that something is the majority or norm, not a rare occurrence.
I hope the Gates belt is stronger than the Continental one, but I don't know for sure.
I think Ghost ultimately was willing to goodwill replace the continental trash with a complete Gates drive system because a continental belt could not be sourced anymore. But, I still have to worry about the nightmare of axle nuts, belt tension, removing the tiny nut from the hub to disconnect the shifting, and removing the brake caliper (!!!) to fix a flat.
But the common IGH's do come with specs for minimum gear ratio front to back (2:1, I think), suggesting an implied torque limit. I've always wondered which part was the weak link.
The cogs wear out under normal use (I've replaced a couple so far) but that's true on derailleur bikes as well.
Well, now you know... especially in 3d gear (when the cross drives the planetary hub by engaging on the top of the cog axles) the clutch is under high load. I often rode that bike with a heavy trailer (made from a shipping crate and some moped wheels which I happened to have lying around) to haul my guitar, amp and saxophone through the Dutch countryside to practice with my band, this may have put too much of a load on the hub.
I am assuming that's what the poster meant by putting emphasis on his frame being a fixed gear one. Those normally have horizontal dropouts to put tension in the chain.
I wonder if the frame wasn't built to allow belt replacement?
I live in a very bike-friendly European town. I use my bike daily. I have seen maybe 10 if these things in the last 3 years, mostly owned by elderly people who were sold high-end e-bikes they don't need.
This expensive ceramic bearings are exposed and will experience significant wear. Properly insulating them would wipe out whatever miniscule gain in efficiency they claim as the insulation increases losses.
Finally reducing chain friction (which is already very low on a tuned drivetrain) to some fraction (that has yet to be proven for real conditions) is tantamount to snake oil in my opinion.
These are just few. I could go on but it is not worthy the typing and mental efforts.
I'm an avid leerer of other's bikes, and in my long and fruitful bike leering career in Europe, I have seen just one (1) gates drive.
I'm a European cyclist and only ever seen conventional chains.
I've built and repaired quite a few push bikes over the years I am still using fairly standard shimano kit. The problem with exotic equipment is that even decent shops might not be able to repair it and it normally requires specialised tools.
I mucked about with Campag and some other exotic kit and it is always a PITA as you always have to go hunting around for parts of ebay after a few years because threads and tapers on things like bottome brackets aren't compatible.
Chains are a wear item, and small gains in the efficiency are going to be lost pretty quickly after the first few times it’s been ground through mud, sand and grit, which will take all of one ride.
More generally, novel drivetrain products often seem to take off early in the tt/tri world which also don't really have to deal with those issues.
It's also worth noting that anything that all else being equal, improved efficiency goes hand in hand with better longevity. As an example, applying a hot chain wax is a winner in terms of watts, but it's also cheaper in the long run.
The trade-off are explicitly made to have reduced longevity to have better efficiency.
Take tires for example. A low rolling resistance lightweight XC tire will have significant advantages over a dual casing 2.6" DH tire. The XC tire will smoke a DH tire but not have better longevity on dirt. The XC tire will be slower on some DH tracks and the DH will be slower on XC. If you ride a DH tire on a road it will ironically wear down more quickly than a typical XC tire, and you can shred an XC tire in one day on technical DH.
Tyres generally trade traction off against longevity, plus, yes, specialization is a big consideration.
The loss in a chain is nearly all in the roller as it engages with the first tooth in the front chain ring. Most of the force is being transferred from this first tooth, and it presses directly on the roller, which is also rolling into its seat position on the tooth. So a better design would have the roller get seated on the teeth before the force gets transferred to it, and then have no rolling until force transfer is done, then roll off gently.
A new chain on a new chainring engages at the bottom of the tooth, right where it seats, and the torque of the chain ring rolls it up the forward tooth ramp until the tangential component of the force pressing into the contact point equals the pedal force. This happens on all points engaged on the sprocket. So you get a lot of rolling, but that’s over a lot of rollers. As the chain wears, it gets longer, so the teeth catch early from the tip, and it rolls all the way down the tooth while the entire chain tension is all on that first roller.
This particular design has no rollers at all. It will still stretch because it has the same pin-plate interface, and it seems that a modest stretch may render it inoperable, but I’m not sure.
The track market is miniscule and we'll catered for. Then the e-bike market does not need a 2 percent gain in chain performance.
The enemy of the chain is dirt. Real world cycling in the 1950s had hub gears and a big case to keep the dirt out. Then derailleur gears aimed at the sports market dropped the chain case. This made sense for cyclists with a team car behind them.
SRAM already went with their own non-compatible design with their latest road groups (AXS road). Bottom bracket "standards" have proliferated over the last 20 years (all 8 of the bikes in my garage use a different system). Hub spacing is non-standard too (100mm/130mm QR, 100/135 QR, 100/135 TA, 100/142 TA, 110/148 TA, Superboost, DH, and a few other niche standards). Even within a brand, there's no guarantee shifters and detailers are compatible.
Basically, the industry has "standards" but only keeps them long enough to develop the next. Gotta keep us buying $5000+ bicycles somehow.
Hub spacing in QR is standard at 100/130 for road, 100/135 for mountain. Thru-axle is somewhat new and I think we'll standardize on fewer than that eventually. I think some of those are a lot more popular than the others.
My current bike a late model Brompton, I am familiar with the extents to which other bespoke components is possible and a deliberate choice over something by Bike Friday.
(Disc brakes in particular are not a good match for QR)
It's a mess. And really annoying for anybody who breaks parts a lot - while almost everything is still available in some form, the newest best stuff is often only available in the latest standards.
Once people take their hobby too far, you will end up with things like this.
For $2K you can buy our (exotic and unnecessarily expensive metal) chain, which reduces friction to 0 and lasts forever.
I ride a fair amount (150-200KM a week in the summers) and am always surprized to see everything on a bike is measured in grams, except the biggest impact, the rider itself?
Sure i shaved 4g on my $400 waterbottle holder.... but when i weight 80KG.. and have another 2kg of water with me, does that 4g really matter?
The idea here, if it is sound and measures well, is basically only useful to track racers (because they race single-speed bicycles). Current chains are extremely efficient, and mostly compatible at the same nominal width (expressed as 10-speed, 11-speed, 12-speed). And they are very cheap. People do spend absurd money shaving grams on bikes, but this product is not really in that space. It requires an IGH or a single-speed and isn't compatible with any other high-end drivetrain components on the market. That's a non-starter even for the people spending $15k on a bicycle.
Here's a better "audiophile" example in vogue in cycling at the moment: ceramic bearings. These cost a lot more than high-quality steel bearings and quickly become less efficient than steel ones because the hard ceramic bearing destroys the softer steel races.
The article spent most of the words focused on high-performance racing.
Plus don't cycling competitions set a minimum bike weight anyways?
And you can show off gear, you can't show off weight loss.
I used to work in a bike shop for about ten years. One time had a guy come in who worked with Kyronics. We all made jokes about freezing dead people - but he said you can apply Kryonics to a wide array of stuff not just dead people.
One of the many things some of the team riders were seriously considering was having their cranks, chains and frames frozen since its supposed to alter the molecular structure to make them stiffer and more durable.
I'm not sure they did it, but it was a topic of constant conversation for weeks afterwards.
https://frozenrotors.com
In a conventional chain the pins cross the sprocket teeth and must rotate across that entire width; more frictional loss.
In this design the saddle seats on the tooth, and just the relatively short pins linking the saddle to the outside chain must pivot.
And that is where this monstrosity will stay, until they find a way to fit it into a 6 speed derailleur system to make it viable for $60 bikes sold in Walmart, and eventually an 11 speed derailleur system.
There are systems that actually could produce less friction, however they can't handle ANY contamination, thus ruling them out.
Your best bet is to look elsewhere. I would try reducing the contact friction as the links engage. To do this, I would recommend using BAM coatings on the chain and sprockets. It has lower friction than Teflon, AND is almost as hard as diamond.
https://en.wikipedia.org/wiki/Aluminium_magnesium_boride
As long as it is not an absolute crap pros would use whatever equipment their sponsor tells them to use. Chain durability for pros does not matter and whatever the difference in friction are really negligible.
>"ability to transfer 25% more Torque"
Any decent chain will handle way more torque than cyclist can deliver so what's the point.
>“four times increase in system lifetime”
I believe it when I see it. Also how much more this puppy gonna cost and cyclists would need to change chainrings and sprockets. This much troubles for the sake of chain? Sorry but I have my doubts.
https://www.youtube.com/watch?v=Q-XOM4E4RZQ
Also I found that watching machining of all kinds of stuff is strangely relaxing to me.
If you spread pressure out offer wider areas, you don’t get less overall friction at least in the first order approximation of friction you find in first year physics.
What it looks like is an attempt to make something better that improves metrics which aren’t necessarily coupled to better overall performance.
It will require new chainrings and cassettes (probably RD rollers as well).
One could say increasing efficiency by 1% equivalent to reducing existing losses by 50%, both of those are reasonable bases, making it a percentage of the existing efficiency feels off.
Anyways it seems to be significantly more expensive thus I don't think it will become widespread.
The rohloff system is quite heavy though, so I don't know if it's "more efficient" than a traditional high end sprocket-and-chain system. The rohloff also shifts the weight to the rear of the bike. Maybe the pinion gear box system might be better since its weight is low and towards the center of the bike.
Having bike toured, keeping a chain halfway clean (or at least not muddy) is not hard. Yes, I see the appeal of an internally geared hub, but marginal differences in efficiency either way would not be high on my list of concerns.
[0] https://cyclingtips.com/2020/05/how-many-watts-does-a-dirty-...
> All of that is working, too, with independent tests showing properly race-prepped drivetrains to be as much as 98% efficient.
> That elusive 2%
> As good as chain optimization has become, there comes a point where there’s no more optimizing left to do, and there are no other options but to rethink the system.
Though, not as in any modern drivetrain but high-end competition drivetrains. At least I imagine it would be with really expensive solutions like Ceramic Speed bearings everywhere.
It can be used with the Rohloff system. But, I think you need a compatible chain ring since they are talking about a new tooth design requirements. The Rohloff system has the chain ring attached to the hub gear. So you presumably have to change that chain ring yourself.
Or, if you're dumb and lazy (me!), ride the whole lot into the ground and replace the whole bike every few years because #shinynewtoy!
I assume this is a typo for 500?
If you ride a chain until it stops working you'll probably reach those numbers. But then you will have to replace the entire drive train which is far more expensive. The chain is the cheapest part and replacing the chain a bit earlier than absolutely necessary will greatly increase the durability of more expensive parts. As a little bonus you'll repeatedly get the joy of riding a new chain. Replacing at the right time is cheaper and more enjoyable at the same time.
For, me that works out to 2x season. The cassettes are $300 and the chains are $40. So, the chains are treated as 100% consumable/disposable.
Typical recommendations are every 500-750miles for a mountain bike. For the average mountain biker I think that would be more like every 125 hours at 6 mph. Mountain bike chains see much more abuse than road, and you can go further too.
You can be more scientific by using a chain ware tool to measure how much stretch there is.
Suspension service intervals are specified in hours, so I use the same for the rest of the bike.
https://www.newmotionlabs.com/articles/blog-post-title-three...
Still, single speed. Get on the podium with track racers.
BTW, my skepticism is very tempered. I still think Biopace was a good idea and could be made to work. I think this is a good idea and I still think it could work. But it has to, you know, work. It has to demonstrate and provide that efficiency rather than just claim it because modern chains are pretty darned good.
(yes, I realize the frame needs to be split to remove the wheel, but in the newest designs this doesn't seem like too big a deal)