First shown at Eurobike 2018, the CeramicSpeed Driven drivetrain concept replaces the chain with a carbon fiber driveshaft being turned by a toothed cog. At the back is a pie-platter sized disc with rows of teeth timed to a series of small bearings that engage to turn the rear wheel. You can read all about the design and tech here.

ceramicspeed driven prototype chainless road bike drivetrain uses a carbon driveshaft

The project is still in the works, with three modified Cervelo P5 bikes in their Colorado offices. The latest update is that they’re “almost” able to shift under power. They’re rideable, but only in one gear.

More recently, they introduced the offroad OSPW system. Word is it’s the first of more gravel, cyclocross and mountain bike systems to come, likely with their adjustable spring rate. That feature lets you set a lighter cage return tension to (slightly) reduce friction when you won’t be on super rough terrain.

One thing they glossed over in the introduction of the off-road OSPW parts was the revised narrow-wide tooth profile on the pulleys. As with anything they do, the design is optimized for performance, in this case to keep the chain on board even when you’re running lower return spring tension. But this particular design came about after reviewing other’s designs and the need to stay on the other side of some big brands’ patents.

Stay tuned for more news from them this year, and we’ll be setting up a call with their team to discuss friction and efficiency on the Bikerumor Podcast…so, got questions? Leave them in the comments here and we’ll be sure to ask!

CeramicSpeed.com

33 COMMENTS

      • There is also healthy skepticism.

        Do you feel its “bandwagon fallacy” that no major carmaker produces a car that runs purely on water or that it doesn’t exist because its not feasible given any known chemistry or thermodynamic law?

        I’m not saying this is as fraudulent. Its probably feasible, but there are so many technical hurdles for this project to be viable that is kinda screams marketing stunt.

    • SRAM and Shimano don’t like other company’s pulley wheels or gears on their products, and they have more pull with the Big 3 than CeramicSpeed.
      Oh, and because it’s very expensive, and the average consumer doesn’t see the value of it. But if you really wanted to spend an extra ~$500 on a more efficient pulley system, then I’m sure it’s something that your bike shop will gladly help you out with.

      • Sram Red already has ceramic bearings in the RD pulleys, it would cost sram like 10 cents more to make the pulleys a larger diameter. If they thought it was worth it and still shift perfectly, they’d do it.

        Honestly, I think the OSPW look dumb and I’d bet that’s why the big 3 aren’t putting the effort into it. Everything on bikes is starting to look lower profile and simple, like shifters and derailleurs shrinking, getting closer to the frame, and blending in better. Cables are getting hidden everywhere so you can’t see them at all. Then you have these giant pulleys sticking out of a very svelte RD, it ruins the look of a bike IMO.

    • Because OSPW will give you marginally marginal gains. something like .1 to .2 of a watt of total savings. It is literally worthless.

  1. This is going to be fail big time. Maybe the knowlegde from research can be used in other space but road cycling … I don’t think this will fly and revolutionize they way power is transmitted to the wheels

    • And by interested, I’m basically saying I will be amazed.
      There are so many other issues. That said, its a great marketing tool, relatively cheap overall and gets plenty of press which can be applied to their otherwise mundane (but big/pricey) pulleys.

      • Full power upshifts have been possible on racecars for over a decade, and the same principle could be used for CeramicSpeed’s gears: you engage the higher gear, and use it to unload the lower gear, which now pops out easily.

        • Technically there is no such thing as a full power shift (sans CVT, but those have high parasitic losses). There are still very short interuptions in torque in modern racing transmissions.

          Regardless, all those transmission have the benefit of larger packaging and weight limits and high power motors. Bicycles are severely limited in that respect. I could see them running two bearing wheels with a ring synchronizer, but that only works if you shift down then up (or vice versa). If you try to keep shifting in one direction, that doesn’t work. Maybe a few ramped teeth timed to the shift mechanism (you ask for a shift electronically, when the timing mark aligns, it slides along the ramp and engages…it would have to be electronic and would not be “fast”)

          Again, it can be done, but there are major hurdles given the constraints (and going against amazing shifting conventional drivetrains)

      • Likewise.

        Methinks they should just scrap the shaft drive shifting and just have it transfer power. Let an internal gear hub or Pinion gearbox do the shifting instead. That seems way more viable, although I admit either option (IGH or Pinion ‘box) also has downsides of its own.

        • Adding a geartrain will completely wipe out the purported efficiency benefit. Chains are inherently quite efficient already.

    • For real though. It’s telling that they don’t say how it ruins your shifting. On aero bikes that already have trouble achieving optimal results, it seems like bad idea.

  2. The spreading torque reacting against the dropout and cluster are SIGNIFICANT in this application. Ripe for failure unless both of these components are VERY Stiff and heavy. Not a win from an overall point of view

  3. Ceramicspeed pulleys are literally a pointless product. Total “savings” are within a margin of error and their marketing multiplies them by a factor of ~10 or more. Here I elaborate why:

    • While I agree that the CS cages and pulleys are a ridiculous and perhaps pointless extravagance, there’s an important incorrect assumption in this video. The reduction of friction with the larger pulleys is NOT limited to bearing friction. The larger diameter pulleys reduce friction in the CHAIN by reducing the amount of bending required to go around the pulleys. This is in line with testing that demonstrates that larger cogs and chainrings reduce friction in the chain.

      Perhaps the energy saved with the pulleys is still insignificant, but considering that the bulk of the friction in the drivetrain comes from the chain, the potential is there to save the 1-3 watts that CS claims.

    • More importantly, how are they going to keep it from flexing toward the spokes under pedaling pressure? Who cares if they can shift it if you can’t apply any significant power to it without it flexing and skipping?

  4. Surely any benefit of increased efficiency from the larger pulley wheel is more than wiped out by the extra friction of the ‘wide’ teeth on the chain?

  5. Why? Specifically, why make the shaft drive shift at all, just put it on a track bike, which seems like the best use case anyway, someone doing an hour record…

  6. Bike Rumor continues to enable this particular marketing stunt. Yet if one notices, they are primarily cheerleaders and don’t ever offer any criticism. Fine. I love their effort to find what is new, no matter if it’s vaporware or what. Yet it would be nice of they could offer at least some objectivity and perspective perhaps.

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