This company is really famous for selling really expensive "upgrades" that do very little for actual speed.<p>The resistance of the chain & pulleys is a very tiny percentage of the whole unless they're gunked up and not maintained/lubricated or are broken.<p>Pretty much all mechanical resistance on a bike is dwarfed by aerodynamic resistance. When the aerodynamic resistance is broken down the contribution of the bike is dwarfed by the contribution from the rider and his/her body position on the bike. When you start getting into the resistance from gear the helmet & clothes are more significant than the bike.<p>None of this stops them from selling $10,000 bikes to amateurs who are slow though.<p>It is free but hard work to go on a core strength + flexibility program that lets you access more aerodynamic riding posture. Working with a good fitter/coach will cost a little but help get there with less guesswork. Everything about getting fast on a bike is harder work than buying stuff.
First, from an engineering perspective, this product is really cool and maybe for some well-funded Tour de France team it could make sense to test this out. But the price point, the lack of compatibility with components of existing drivetrains and the lack of compelling reasons to make the change, are going to be headwinds to adoption.<p>On page 3 of their brochure (<a href="https://www.ceramicspeed.com/media/2979/driven_brochure.pdf" rel="nofollow">https://www.ceramicspeed.com/media/2979/driven_brochure.pdf</a>), they're showing 0.5% - 1.0% efficiency gains over a traditional drivetrain that is <i>cross-chained</i>, meaning that if you use a traditional drivetrain correctly (i.e., shifting so as not to cross-chain) the gains are likely significantly smaller.<p>As ben7799 said, this company is primarily in the business of selling very expensive products that have minimal impact on performance.
I'm sure this is a neat system, but it's worth noting that bicycles are already very efficient, the difference between their claimed efficiency and a properly set up traditional drivetrain is maybe one or two percent.<p>And any weight savings are probably useless due to the minimum weight required for racing. Pro bikes are basically at the point where they're having to add weight just to pass inspection. This system might have a bit less rotational mass in the "cassette" than a traditional cassette which would help.
chains are a pain. But belt drives have been around for 10 years now and you hardly see them.<p>Chains are the most complex part of the bike with the most moving parts. You have to lubricate them, they stretch.. But they work well in all variety of conditions (even rusty and squeaky) and are fairly cheap.<p>Sheldon Brown's (RIP) bike pages have some good articles on the good old chain.<p>old school html ahead:
<a href="https://www.sheldonbrown.com/chains.html" rel="nofollow">https://www.sheldonbrown.com/chains.html</a><p><a href="https://www.sheldonbrown.com/chain-wear.html" rel="nofollow">https://www.sheldonbrown.com/chain-wear.html</a>
Video of it working:<p><a href="https://www.youtube.com/watch?v=UFAQ6CzNm7s" rel="nofollow">https://www.youtube.com/watch?v=UFAQ6CzNm7s</a>
I couldn't figure out what it was from the page, but the linked PDF has more information (rolling pinion to what looks like a driveshaft)<p><a href="https://www.ceramicspeed.com/media/2979/driven_brochure.pdf" rel="nofollow">https://www.ceramicspeed.com/media/2979/driven_brochure.pdf</a>
How do they keep the bearings from skipping over the rear gear/disk? That disk and driveshaft would have to be extremely stiff to avoid flexing, especially in lower gears where the contact point is further out, and it looks like just a couple millimeters of flex will give enough space to skip.
As far as I'm aware chain was introduced to allow for light weight while keeping vibration resistance.<p>Can't this pulley system be trimmed down even further to one bar transmission?