A Revolutionary Drivetrain Concept that Eliminates the Need for Derailleurs and Chains
CeramicSpeed, with the Mechanical Engineering Department at the University of Colorado, have created a revolutionary drivetrain concept – Driven. 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. CeramicSpeed’s new Driven concept impressively eliminates all eight points of sliding friction.
To achieve the ultimate performance, Driven uses CeramicSpeed Bearings in a pinion style drive shaft system. In total 21 CeramicSpeed Bearings play a crucial role in the functionality and efficiency of Driven. Thanks to their extremely low rolling friction and longevity, the bearings transfer torque from the front ring through the drive shaft, then onto the 13-speed rear cog.
At the head of CeramicSpeed’s Driven Project is company Chief Technology Officer and founder of Friction Facts, Jason Smith:
“CeramicSpeed has proudly accomplished what many have said couldn’t be done. We’ve achieved a 99% efficient multi-speed drivetrain while eliminating the chain and complex rear derailleur. Advancements in drivetrain technology have been evolutionary since the 1920’s. Driven is truly revolutionary given its unique rolling element power transfer and unmatched efficiency. The Driven concept has the ability to change the way the cycling industry views drivetrain design and drivetrain efficiency.”
The objective was to increase the optimal drivetrain efficiency to 99% which is currently benchmarked by a conventional Shimano Dura-Ace drivetrain at 97.8% at 380w loading and 97.21% efficient at a 250w loading. Currently the most efficient drivetrain available within cycling is a conventional Shimano Dura-Ace drivetrain upgraded with a CeramicSpeed bottom bracket, Oversized Pulley Wheel System and UFO Racing Chain, this upgraded drivetrain measures at 98.37% at 380w loading and 98.08% at 250w loading.
For conventional drivetrains, the testing has been performed on a High-Precision Chain Efficiency Tester and loaded accordingly to simulate a rider output. The testing machine for Driven has been created to answer the same test parameters as the HighPrecision Chain Efficiency Tester used for the conventional drivetrain testing.
The test results have been measured up to 100 watts output and extrapolated to 500 watts after a pattern took shape. In the graph below, you can see the difference between Driven, a CeramicSpeed optimized drivetrain and the standard Dura Ace drivetrain. The chaindrives have been calculated for real-life application, taking into consideration the cross-chaining effect. Thanks to the lack of chain in the Driven setup, the cross-chaining effect and all sliding friction is eliminated.
At this stage, Driven is a still a prototype, a revolutionary one, but a prototype. The patent has been submitted. It encompasses the potential to challenge the way we look at the conventional drivetrain efficiency and overall performance.
Further development options for Driven can include, a double row ball bearings (further increasing the efficiency levels), a more optimized, possibly asymmetrical tooth design, material testing (advanced lighter and durable materials for the rear cog and front ring). The patent includes the possibility for a powermeter inclusion inside the shaft and a compact shroud can encapsulate the entire drivetrain to protect from mud, rain, and contamination.
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