French Start-Up Integrates Gearbox With E-Bike Drive Unit

CLUSES, France – The company is named Kervelo and has a background in the automotive industry. At last month’s Eurobike it presented a striking combination of a 4, 6 or 12 speed gearbox with a 250W drive unit that fits with the current trend of highly integrated e-bikes.

At Eurobike Kervelo presented its Quartz drive unit in combination with a planetary Kernel labelled gearbox. The company claims that this combination brings “Less moving parts for better mechanical reliability. And it was engineered from the drawing board to work with electrical assistance to deliver a highly reliable drive unit.”

The Kervelo Quartz drive unit is mounted in the downtube while the 126mm diameter hub, housing the gearbox, remains visible. The company emphasizes that its motor-gearbox integration brings more design options for nicer frames as well as high ground clearance to protect the drive unit.

Kervelo’s Quartz 12 speed drive unit weighs 3.9 kgs. “It delivers as much torque, power, and gears as almost every other system currently available, for a fraction of the weight and in a reduced visible volume. Its architecture warrants for longer maintenance periods, up to 10,000 km or once a year only, using standard gearbox oil.”

The Quartz-12 speed drive unit that offers a total gear ratio of 545% in combination with the 250W motor delivering 70Nm in torque makes it a fit for e-MTBs. Quartz-6 is Kervelo’s city-bike version with a 323% ratio and 250W electrical assistance while Quartz-4 with 200% gear ration and 250W motor is claimed to be mostly for bike-sharing platforms.

The French start-up offers its drive units with frame ‘bridges’ in either aluminium or steel. Kervelo starts delivering its gearbox-drive units combination next November.

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