The company Ceramicspeed has developed a bicycle concept they say will revolutionize the bike. The concept bike called ‘Driven’ grabs attention with its radical looks and the even more radical claim of better-than-99-percent efficiency.
When it comes to bicycles, innovation has been quite traditional, making minor efficiency adjustments to the already established concept of a bicycle design.
Traditional bicycles with multiple gears have a drivetrain that determines the relation between the cadence, the rate at which the rider pedals, and the rate at which the drive wheel turns. And a gear ratio that depends on the ratio of the number of teeth on the chainring to the number of teeth on the rear sprocket (cog).
Even though the transmission systems have been improved and different forms of power transmission have been tested, using new materials and superior minor design changes. But on the whole, no radical changes that challenge the basic concepts have been introduced for many decades.
This changes now with a radically different concept that challenges the basic concept of how a bicycle is supposed to be designed. The concept is presented by the Danish company Ceramicspeed who, together with engineers at the University of Colorado, has developed an alternative to the bicycle drivetrain system.
Not only does it weigh less, is less bulky and have a lower air resistance – it should also produce 49 percent less friction than conventional drivetrains (tested against Shimano’s top system Dura Ace).
According to CeramicSpeed’s testing, that best-case chain and derailleur drivetrain is Shimano’s Dura-Ace enhanced with CeramicSpeed’s Oversized Pulley Wheel System (OSPW), and the company’s UFO chain which returned about 98-percent efficiency (averaged across all gear combinations). A stock Dura Ace drivetrain returned about 97-percent efficiency.
According to the information provided by CeramicSpeed, this means that Driven has 32-percent less friction than the CeramicSpeed enhanced drivetrain, and 49-percent less friction than the stock Dura Ace drivetrain.
The efficiency gain comes from eliminating a chain and derailleur’s eight points of sliding friction. Driven has, “two points of higher-efficiency bearing roller friction,” according to the materials provided by CeramicSpeed’s representatives.
The concept i.e. removes the chain with its eight different points where sliding friction occurs and replaces it with a drive shaft that only has two points with rolling friction.
“DrivEn creates 49% less friction than a stock [Shimano Dura-Ace] drivetrain averaged across all gears,”
“When that Dura-Ace system was optimized with a CeramicSpeed OSPW and UFO racing chain, DrivEn created 32% less friction. From an efficiency standpoint, DrivEn hits the magic 99% efficiency number at 380W of rider output.”
– CeramicSpeed chief technology officer Jason Smith, who founded the once-independent drivetrain friction test facility, Friction Facts.
The concept that was shown at the Eurobike 2018 fair had either one or 13 gears, but putting on more should not be a problem. The gears are supposed to be electronic (battery power, servo and a wireless receiver are in the drive shaft).
The gearchange will not happen immediately, but the system will calculate when it is appropriate to complete the gear change – a bit like an automatic gearbox in a car. But Smith says a gear change will be perceived as “almost at once”.
“Ceramicspeed is proud to have done something that many said did not go. We have achieved 99 percent efficiency in a multi-axle system while removing the chain and the complex rear axle. The “Driven” is truly revolutionary with its unique power transmission and efficiency. The concept can very well change how the bicycle industry looks at powertrain design and efficiency, “
– Jason Smith.
Even this this isn’t first system with a drive shaft developed for bicycles, it has been tested before. But none of these has been as effective as the design that Ceramicspeed has developed if the claims are indeed true. But if the concept becomes a business success remains to be seen.
Check out the below video for an in-depth demonstration of the system.