In conjunction with the University of Colorado's Mechanical Engineering Department, bicycle parts manufacturer CeramicSpeed has launched an ambitious initiative: To produce a bicycle with no chain nor derailleur.
At this year's Eurobike show they unveiled Driven, a 13-speed "prototype" ("concept bike" would be more accurate, as the thing doesn't actually work) that uses bearings and a wicked-looking 13-ring cog that you don't want to slam your shin into:
Driven creates 49% less friction when compared to the market leading chain and derailleur drivetrain. A traditional chain and derailleur drivetrain contains eight points of sliding friction, which is generated from the articulation of the chain at these points. Driven impressively eliminates all eight points of sliding friction.
Naysayers and skeptics will say the cost, plus the additional weight of whatever housing system would be required to keep mud out, would nullify the efficiency of the design. And there's probably a very good reason that bicycle chains have persisted since their introduction in the late 1800s. But ultimately, innovation comes about by people and companies spending a lot of money to try out new things. So I'd say we learn what we can from this, and be grateful that it's not our money.
Plus I can't deny that if they get that pinion working, it'd be awfully cool to see in action.
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I was at Eurobike and had a chance to see it in action.
Gilles, I was at Eurobike as well. Did you happen to see both prototypes? There was one at their booth (single speed) and another in the awards section of the show with 13 speeds. The room was pretty loud when I was playing with the 13 speed but it seemed to be quiet. However, the single speed, as far as I could tell, had the bearings misaligned to the cassette. Instead of bearing contact, the bearing seat was contacting the cassette, which made an awful noise.
Gives a whole new meaning to the term Road Rash.
Basicaly this is shaft drive, except the gears (99%are enhan
That is some good marketing ("Driven creates 49% less friction"). That statement isn't super meaningful as chain drives already have very low friction. What is meaningful is how much of an efficiency gain it would produce (Efficiency = Power Out/Power In, and Power Out=Power In - Friction Losses). Chain drives are already 95-98% efficient, so the biggest possible gain would be ~5%. That being said, it wold still be cool to see a working version.
Could the axle of the drive shaft be the chain stay?
What's with the 18650 battery cell in the drive shaft?
I suspect it's for shifting