5 ms·

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

by usrusr 6y 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 6y 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.
- mpol 6y 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.
  - lostlogin 6y 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.
  - olau 6y 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.
  - usrusr 6y 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 6y 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 6y 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 6y 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 6y ago
        3) broken valve 4) badly seated valve tip (dirt?)
  - jacquesm 6y 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.
- gameswithgo 6y ago
  bikes like that have existed, its possible. might be heavier by a bit.
- justinator 6y 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.
- rconti 6y 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 6y 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.
    - jacquesm 6y ago
      Indeed. The only time you remove the wheel is to replace the tires.
    - xorcist 6y ago
      Isn't hard to find small punctures with the tube still stuck around the wheel?
      - zrobotics 6y 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.
- lmm 6y ago
  The Strida Evo works like that: hub gears, but both wheels are single fork.
ska 6y 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 6y 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 6y 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 6y 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.
  - usrusr 6y 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?
  - deleted 6y ago
    [deleted]
usrusr 6y 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
aasasd 6y ago
Elementary: one roller pushes the tooth, the other one pulls.
- usrusr 6y ago
  How would a roller pull? Magnetism? Suction? Capturing the tooth in engaging conversation?
  - aasasd 6y ago
    Black magick.

by usrusr 6y ago

lostlogin 6y 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.

mpol 6y 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.
- lostlogin 6y 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.
- olau 6y 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.
- usrusr 6y 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 6y 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 6y 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 6y 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 6y ago
        3) broken valve 4) badly seated valve tip (dirt?)
- jacquesm 6y 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.
gameswithgo 6y ago
bikes like that have existed, its possible. might be heavier by a bit.
justinator 6y 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.
rconti 6y 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 6y 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.
  - jacquesm 6y ago
    Indeed. The only time you remove the wheel is to replace the tires.
  - xorcist 6y ago
    Isn't hard to find small punctures with the tube still stuck around the wheel?
    - zrobotics 6y 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.
lmm 6y ago
The Strida Evo works like that: hub gears, but both wheels are single fork.

ska 6y 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 6y 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 6y 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 6y 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.
- usrusr 6y 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?
- deleted 6y ago
  [deleted]

usrusr 6y 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

aasasd 6y ago

Elementary: one roller pushes the tooth, the other one pulls.

usrusr 6y ago
How would a roller pull? Magnetism? Suction? Capturing the tooth in engaging conversation?
- aasasd 6y ago
  Black magick.