It would be fair to say that mountain bikers everywhere have had a bad experience with a derailleur at one time or another, which is what drove Cedric Eveleigh of Lal Bikes to create the Supre Drive, a drivetrain system that separates the two functions of the standard derailleur (shifting and tensioning the chain), while also placing the purpose-built derailleur out of harm’s way. The Supre Drive’s four key elements are durability, efficiency, chain damping, and a lower unsprung mass, all on a high pivot suspension platform.
The idea popped into the Canadian mechanical engineer’s head one day while he was catching his breath on a ride in the spring of 2019, and he immediately set to work building a stationary prototype drivetrain. Cedric has patented the Supre Drive in Canada, and while the patent is pending internationally, he is already working with a major mountain bike company to create a frame that will use the system. The prototype in the launch video is limited in range, but the current version can accommodate a 10-51-tooth range cassette and only has two specific requirements; a 52 mm chainline and a T47 bottom bracket.
Supre Drive Details
• High Pivot Idler Suspension Design
• Uses standard hub, cranks, cassette, shifter, and chain
• 12-speed, 10-51T gear range
• Custom derailleur with large, single jockey wheel
• Generous ground clearance
• Frame offers derailleur protection
• Spring loaded chain tensioner connected to spring and damper in downtube
• Approximate constant chain tension across all gears
• More info: lalbikes.com
• Instagram: @lal_bikes
A derailleur’s first job is to push the chain across the cassette cogs to change the gear ratio. Secondly, the pulley cage tensions the chain when slack is created by shifting to smaller cogs, keeping it from jumping off of the front chainring and cassette as the bike bounces down the trail. Cedric has placed the cage-less derailleur inboard on the swingarm and moved the chain tensioner to the middle of the bike, above the chainring. Although it uses a conventional hub and drivetrain parts, the frame must be designed around the entire system.
The tensioner pivots around the bottom bracket axis and extends counter clockwise to provide more slack in the chain when the derailleur shifts to the larger cassette cogs. Conversely, when an upshift is made to a smaller cog, the tensioner is pulled by a cable towards the front of the bike by a cartridge in the downtube, controlled by a spring and damper. Most intriguing is the system keeps the chain tension nearly identical across all gears. Conventional drivetrains increase tension in the lower gears, causing an increase in drag.
Add in a shorter section of free chain and as Cedric claims, “Speed-sensitive tensioner damping that outperforms any derailleur clutch on the market”, and you get an extremely quiet and damped drivetrain. The Supre Drive also uses the same number of jockey wheels as a conventional high pivot idler bike, but reduces the friction since those wheels have a larger number of teeth than the typical derailleur.
As for the unsprung mass debate, the system saves roughly 130-grams of unsprung mass, but adds 100-200 grams of total mass. Like Pinkbike’s Seb Stott discussed in his recent article about why you shouldn’t worry about weight much, there are potential benefits to increasing that sprung to unsprung ratio by adding more weight to the front triangle and less to the rear.
After meeting Cedric back in August on his venture through B.C. from Chelsea, Quebec, I was presented with the opportunity to parking lot-test the second Supre Drive prototype. In a blindfolded test, I would not be able to tell the difference in the shifting system versus a traditional layout. If anything, the Supre Drive should shift even better on the trail, because the derailleur is mounted at two points and therefore does not rotate around on the B-knuckle pivot.
The fact that there is no B-tension adjustment needed and no special tools are required to assemble the system helps simplify setup. The positioning of the derailleur also gives more chain wrap around the cassette because the jockey wheel is clocked much higher. Almost hidden in plain sight, the derailleur also has abundant ground clearance and is further protected by being nestled between the chain and seatstay. Adding to the benefits of the system, the chain is kept further away from the elements and won’t contact the ground under oscillations.
Production for the drivetrain components will be headed up in Canada by Lal Bikes and incorporated by Cedric. The brand name comes from Pierre Lallement who was credited by some as the inventor of the bicycle. Where does the Supre Drive get its name? Cedric explains, “Supre means above in the Esperanto language. This refers to the Supre Drive being above other drivetrains, both physically and performance-wise.” He genuinely wants to make the mountain biking experience better and more reliable.
As you can imagine, the creation of this idea didn’t happen overnight, but Cedric is extremely savvy and highly educated. The mechanical engineer by trade has a masters in Engineering Physics and taught himself how to TIG weld by watching YouTube videos and built on his machining practices learned in school. This is not the first time he’s put his passion to improve bikes to the test. Back in 2012, he participated in Pinkbike’s Reality Redesigned innovation contest and submitted a Pinion gearbox-equipped downhill bike design.
There have been a lot of wild and wacky drivetrain iterations throughout the years; Honda’s RN01 “derailleur in a box” with a continuous drive chain, Zerode’s high pivot design centered on an internally geared hub, Cavalerie’s belt-driven gearbox DH bike, Lahr’s CVT project, Allan Millyard’s single-sided swingarm DH bike that enclosed the chain in an oil bath. The industry has never seen anything like the Supre Drive before, tackling multiple problems at once, like exposed derailleurs, chain kickback, but still using readily available drivetrain and hub components. All eyes will be on Lal Bikes to see what brand has licensed the Supre Drive, how it will be applied, and who else might in the future.
Advantages of the Supre Drive
1. Ultra durable
No more broken derailleurs because the derailleur has two mount points, it’s protected by the frame, and it stays far from the ground.
More efficient than a gearbox, and more efficient than other high pivot bikes because of the large pulleys and a constant chain tension system that reduces drag.
While 100–200g heavier than conventional derailleur drivetrains, it’s much lighter than gearboxes. The system also reduces unsprung mass (by around 130g compared to XT) because the derailleur weighs less and because there’s less chain near the cassette.
3. Well damped
Speed-sensitive tensioner damping outperforms any derailleur clutch on the market.