CeramicSpeed’s incredible chainless drivetrain now claims to be the most aero too

CeramicSpeed stole headlines last year with an extraordinary rethinking of the bicycle drivetrain; the chainless, ultra-low friction Driven system.

Now, in collaboration with Specialized, the Danish brand claims that Driven is the most aerodynamic drivetrain in the world, and that the Driven-equipped S-Works Venge is the most aerodynamic road bike ever tested in the Specialized Win Tunnel.

CeramicSpeed is also hinting that a shifting mechanism for Driven will be forthcoming, something the original concept lacked.

Driven (previously styled as “DrivEn”), uses a driveshaft with a ring of CeramicSpeed bearings at either end that engage with teeth on a flat ‘cassette’ and chainring.

The design requires a dedicated frame and, at its original launch, it claimed to reduce drivetrain friction by 49 percent compared to a standard Dura-Ace groupset.

The most aerodynamic drivetrain ever?

According to Specialized, the Driven-equipped Venge “showed an aerodynamic improvement over the current day Venge of approximately 3 percent consistently across all yaw angles” in the wind tunnel, a saving which could amount to “as much as 8 seconds over 40km” in the real world.

Specialized aerodynamics R&D lead Ingar Jungnickel notes that this is an advantage comparable to that of the current S-Works Venge over the old Venge ViAS.

Images provided by Specialized appear to show a fully finished S-Works Venge with a driveside chainstay that’s been raised to accept the Driven shaft drive.

The frame could, of course, be a mock-up, but it’s a very convincing one if it is, suggesting that Specialized has invested heavily in the project.

In some photos, the Driven rear bearing assembly is hidden in an aerodynamic shroud, and the performance graphic Specialized has published indicates that this creates a further reduction in drag over the bare drivetrain.

The crank used for testing is notable too. It combines the Driven ‘chainring’ with Specialized’s own S-Works Power cranks, with the power meter module visible on the frame side of the right-hand crank.

Driven is still a concept, but development is ongoing

It’s clear that the CeramicSpeed parts are very much still prototypes. Machining marks are clearly visible on the inside of the front ring in Specialized’s photos and, as yet, we’ve seen no details on how a Driven system might actually change gear.

Having said that, the project appears to be very much ongoing, with the head of CeramicSpeed’s cycling division Martin Banke claiming “incredible advancements” in the last 10 months.

The focus, he says, has been on “rideability and shiftability”, and a Driven system has been tested on a velodrome at speeds in excess of 45km/h.

Banke also alludes to “major breakthroughs in a shifting mechanism that we’re excited to unveil in due course” but there’s no detail at all as to what this might involve.

When the original concept debuted, it was speculated that a wireless servo inside the shaft might move it fore and aft to engage different gears, but right now we’re none the wiser.

In any case, it’s a fascinating design which, if it can be made to work, could truly revolutionise bicycle drivetrains.

And even if it can’t, it’s refreshing to see some genuine innovation in an area where the fundamentals haven’t really changed for over half a century.