No derailleurs, no chain, just a shaft-driven drivetrain with a cluster of bearings. That’s what’s at the heart of the new concept launched by US bearing-maker Ceramic Speed, in a partnership with the University of Colorado’s Department of Mechanical Engineering. Whether or not this becomes the standard on all our bicycles remains to be seen, but this is certainly something to get us traditional cyclists thinking hard: the makers claim 49% less friction than traditional chain and derailleur drivetrains.
This concept features a shaft drive (hence no chain) and a cluster of 21 Ceramic Speed bearings which transfer the power to the 13-speed rear cog. (Motorcycle fans will recognise this transmission system from BMW and Moto Guzzi motorcycles.) The makers claim they have achieved “99% efficiency” in transference of power from pedals to wheel by using a shaft drive. We think it looks pretty cool, whatever the science.
The concept, dubbed Driven, is a great way to show off your main product, of course — CeramicSpeed makes ceramic bearings, and the core of this shifting mechanism is a cluster of 21 bearings. The company says that this design effectively eliminates all “eight points of sliding friction” caused by the chain and derailleur drivetrains.
Food for thought
There are just two points of rolling friction on the Driven — where the bearings connect with the teeth at the crank and at the rear wheel — but the makers say this is much less friction than found on a traditional derailleur-geared chain-driven bike. Even though there might be some serious cleaning to do if this ever got out on the road, the concept is a great way to get us all thinking about the efficiency of our own bicycle drive trains. And who knows, these may get UCI race approval in, say, 2050… ?