The Lal Bikes Supre Drive is a new mountain bike drivetrain that separates the two functions of a rear derailleur – shifting and tensioning the chain – to improve reliability and efficiency while riding, compared to a typical external rear derailleur.
Combining the “efficiency and low weight of derailleurs” with the “reliability of gearboxes”, the system houses the custom-made rear derailleur within the rear triangle, with a damped chain tensioner, which doubles-up as a clutch, rotating around the crankset to take up slack in the chain.
Debuting at Eurobike 2022, Nicolai – a brand that has lots of experience experimenting with new drivetrain technologies – will be the first to offer the Supre Drive on a production bike, with the Nucleon 16.
Speaking to BikeRadar, Cedric Eveleigh – the designer of the patented system – confirmed other brands have expressed interest in the system with further news to follow.
How does the Supre Drive work?
The Lal Bikes Supre Drive separates the two functions of a rear derailleur – shifting and chain tensioning.
At the rear, a diminutive custom rear derailleur, sitting inside the rear triangle, takes care of shifting the chain across the cassette.
As it is housed within the rear triangle (rather than hanging below the chainstay, as all typical rear derailleurs do), Eveleigh claims it is less likely to be damaged while riding.
The chain tensioner pivots clockwise to take up slack in the chain as shifts into smaller cogs.
The chain tensioner is connected via a cable to a spring and damper, which is housed in the downt ube of the bike.
This spring tensions the chain, with the damper acting in a similar fashion to a typical clutch in a derailleur, preventing the chain from whipping about in rough terrain.
According to Eveleigh, a typical clutch drivetrain increases tension in lower gears, which results in an overall decrease in drivetrain efficiency.
His system is said to keep chain tension nearly identical across all gears, reducing drag.
In addition, the idler pulley and tensioner pulley are slightly oversized. This will further improve efficiency as the chain articulates less than it would around smaller pulleys.
The system is shifted using a standard 12-speed Shimano shifter and uses matching 12-speed Shimano cassettes, though Eveleigh is “interested in developing a complete Supre Drive” in the future.
Supre Drive compatibility explained
The Lal Bikes Supre Drive presents a significant shift from the largely standardised layout of an external drivetrain, so it requires a bike to be designed with the system in mind from the ground up.
In terms of specific design requirements, the system is also currently only compatible with bike designs that feature an idler pulley. High-pivot bikes most commonly feature an idler pulley.
According to Eveleigh, this is because the idler pulley redirects the chain, giving the chain tensioner room to move.
In any case, Eveleigh claims “you just get hands-down better suspension with a high-pivot bike”, so sees no disadvantage to requiring a high-pivot design on Supre Drive-equipped bikes.
In addition, the system requires a T47 bottom bracket and a 53mm chainline.
Nicolai Nucleon 16
The Supre Drive system pictured is fitted to the all-new Nicolai Nucleon 16.
The Nucleon 16 is a 165- 0r 178mm travel high-pivot enduro bike.
Previous iterations of the bike used a 14-speed Rolhoff internal gear hub fitted to the front triangle to provide more reliable – albeit slightly draggy and heavy – shifting than a conventional external derailleur drivetrain.
Prices start at €3,099 for a frameset with matching EXT Storia shock, rising to €7,500 for a complete bike.