Does adding a concept drivetrain make "the most aerodynamic road bike" more aero? According to new wind tunnel tests from the Specialized / CeramicSpeed collaboration, the answer is "yes" — to the improvement of 3% for the Driven-equpiped Venge over a normal Venge, which previously claimed the slippery-bike title.
When CermicSpeed introduced Driven as "The World's Most Efficient Drivetrain," the photos and claim of 99.2% efficiency caught lots of attention. We found the idea distinct, however, and still, CeramicSpeed has only shown that it works nominally. That means that while they've succeeded in creating an efficient and aero drivetrain, they still haven't answered the important questions we and other riders and keyboard engineers have asked about it: Will it truly work on the road and under heavy load, like sprinting? What's the drivetrain weight? Will Driven be as efficient as it wears and how quickly will it wear?
Until those questions are answered, understand for now that Driven is aero and promising, but still a concept that could fall short in other ways.
CeramicSpeed and Specialized explore aero benefits of radical drivetrain concept
Specialized Venge outfitted with CeramicSpeed's Driven becomes the most aerodynamic road bike.
Drivetrain efficiency and bearing specialists, CeramicSpeed, have advanced their pursuit to innovate and disrupt the bicycle drivetrain industry.
Since unveiling Driven in 2018 – a revolutionary drivetrain concept which eliminates the chain and derailleurs – the Danish company has recently collaborated with bicycle giant Specialized to put the chainless system through its aero-paces.
To date, the Venge is Specialized’s most aerodynamic road bike, with every aspect of its design challenged and tested. Continually striving to set new benchmarks, the engineers at Specialized opened the door to CeramicSpeed with an interest to examine the true potential of Driven and the aero gains that could be achieved with such a radical drivetrain.
Chris Yu of Specialized spoke of the importance for companies to seek innovation in cycling; "Our motto at Specialized is "Innovate or Die.” This means we are constantly looking at new concepts that offer true performance benefits for our riders. Significant innovations in drivetrains don’t come around often, so we were eager to test the aero performance of Driven in our Win Tunnel.”
Driven, an innovative pinion-drive-shaft design, that utilises 21 CeramicSpeed bearings, was custom designed for the experiment by CeramicSpeed’s Boulder based R&D lab and led by Jason Smith, CTO of CeramicSpeed. Driven was then retrofitted to a Venge for the tests, pitting it against a standard Venge in the renowned Win Tunnel at Specialized’s Morgan Hill campus.
After hours in the tunnel, the results reveal that a Driven equipped Venge is the most aerodynamic road bike ever tested in the Win Tunnel.
The concept bike showed an aerodynamic improvement over the current day Venge of approximately 3 %, consistently across all yaw angles. According to Ingmar Jungnickel, Aerodynamics R&D Lead at Specialized;
"The aerodynamic improvements seen with the Driven drivetrain could be as much as 8 seconds over 40km, the results we measured are comparable of the aerodynamic improvement of the Venge ViAS to the current generation Venge. On a flat course, the aerodynamic gains made are in the same order of magnitude as the gains through the reduced drivetrain friction. Considering that was the first attempt, it seems that the system has the potential of further aerodynamic gains in the future."
CeramicSpeed set out to establish a new benchmark in drivetrain technology by increasing optimal efficiency to 99%. Driven, already the most efficient drivetrain, looks likely to become the most aerodynamic drivetrain to date with validation from the Win Tunnel experiments.
"When we first embarked on the Pursuit of the 1% Drivetrain initiative, the Product Engineering and Design team’s focus was to achieve the utmost level of mechanical efficiency, yet aerodynamic efficiency was always in the back of our mind. During the early phases of development, it became pretty clear that Driven might very well turn out to be the most aerodynamically efficient drivetrain. But speculation means nothing without quantitative testing. Thanks to the rigorous aero testing at Specialized’s Win Tunnel, it has been proven that significant aerodynamic gains can be captured with Driven. It is quite an incredible R&D accomplishment to achieve the most efficient bicycle drivetrain ever developed…both mechanically and aerodynamically”, said Lead Engineer and CTO at CeramicSpeed, Jason Smith.
Whilst Driven currently remains a concept, the Win Tunnel results are thought-provoking, with a few unanswered questions remaining about rideability, shifting and the future of drivetrains.
The head of CeramicSpeed’s Cycling division, Martin Banke spoke with great excitement on the future of drivetrain technology:
"Since we launched Driven at Eurobike last year, rideability and shiftability has been our primary R&D focus and we have made incredible advancements in only 10 months. We’ve surpassed a speed of 45 km/h during rider load testing at the velodrome, and have had major breakthroughs in a shifting mechanism that we’re excited to unveil in due course. We’re now looking forward to showcasing how Driven and the developments we’ve made can truly shift the future of bicycle drivetrains.”
With mechanical and aerodynamic efficiency established, rideability making good progress, and shifting confirmed as the latest breakthrough, can a chainless drivetrain truly be the future of cycling?