Mavic make sub 10kg e-bikes a reality as it launches the ultra-light X-Tend drive system

The Mavic X-Tend drive fitted to a bike
Yes, that is an e-bike motor, not just an oversized bottom bracket (Image credit: Mavic / G Chenard)

Mavic has just announced its intention to become a player in the e-bike motor market with the launch of X-Tend – an ultra-compact, French made, 250W drive system that weighs just 1.2kg. This is partnered with a 1.8kg, 360Wh battery designed to be housed in the downtube. The entire system is claimed to weigh 3.2kg and has enabled the production of a road bike, built by their partner BMC, which weighs under 10kg – which would make it the lightest e-road bike yet produced. The new bike is currently a concept build only though and Mavic say complete bikes will be in production around 2025-2026.

In development for four years to this point, the X-Tend motor is impressively compact. The 87mm diameter drive unit is designed to slot straight into an 88mm bottom bracket shell specifically designed for the Mavic motor and looks more like an oversided BB than an e-motor. The unit uses brushless internals that can spin to 4,500rpm and connect to a double-ringed cycloid reducer, which in turn is connected to a frictionless clutch mechanism. Handily, the drive is designed to be compatible with regular Shimano Hollowtech II cranksets and so gives a standard Q-factor (the distance between the two pedal attachment points on the cranks). The motor also comes with an in-built power meter with +/- 2 percent accuracy.

A cutaway shot of Mavic X-Tend drive unit 120,000 of real, world testing km into the system

The X-Tend drive unit is covered by 15 different patents (Image credit: Mavic)

Mid-mounted micro muscle

The assistance provided by X-Tend is described as feeling totally natural and the motor is claimed to have zero residual friction when the cranks are turned by leg power alone. With only minimal adaption required to convert an existing frame design to run X-Tend, Mavic reckons that it's the only mid-mounted motor system (as opposed to rear wheel drives found on the likes of Mondraker's Dusty) that doesn't disrupt a bike's original design and personality, likening the experience as akin to riding a "muscular bike". With a temporary maximum output of up to 50Nm and 390 Watts (37Nm and 250W normally) it's comfortably in the ballpark of other lightweight motors from Fazua, TQ, Mahle and Specialized.

There's more to an e-bike than just the motor though of course, but Mavic feel that X-Tend's slimline and lightweight 1.8kg battery will cause minimal disruption to bike feel and handling. A 360Wh capacity maybe pretty low these days, but anyone investing in a X-Tend equipped bike will have the option of beefing up the battery capacity by an extra 180Wh via a plug-and-play 1.2kg range extender that bolts onto bottle cage mounts.

As things stand, riders will get three levels of pedal assistance at 30 percent, 60 percent and 120 percent of human input. Mavic have not yet released much in the way of motor management details, but Bike Radar has reported that X-Tend prototypes use a smart phone app.

Zap to the future

It's really intriguing to see this new development from Mavic but it's not the first time they've dabbled in bike electronics. Their 'Zap' road bike gears won Tour de France yellow jerseys in 1994 and 1997 for UK cycling legend Chris Boardman. The fact that a brand best known for their wheels hasn't chosen to go with a hub based motor is surprising too. Given the minimal disruption required to adapt existing frame designs to run X-Tend we expect to see the system running being lapped up by a wide of bike brands across a wide range of bike types. If X-Tend proves itself to be robust enough for the trails, its super lightweight nature will bring a ton of benefits to off-road riders too.

Tech specs: Mavic X-Tend

  • Drive unit max power: 390 Watts (normalized power 250W)
  • Drive unit weight: 1.2kg
  • Battery capacity: 360 Wh
  • Battery weight: 1.8kg
  • Total system weight: 3.2kg (including power meter and BB bearings)
  • Range extender capacity: 180Wh battery (fits into bottle cage)
  • Range extender weight: 1.2kg
  • Availability: 2025 to 2026
Richard Owen
Editor, Bike Perfect

Rich is the editor of the Bikeperfect.com team. He has worked as a print and internet journalist for over 24 years and has been riding mountain bikes for over 30. Rich mostly likes hitting flowy yet technical trails that point downhill. A jack of many trades, he has competed in cross-country, enduro and long distance MTB races. A resident of North Devon, Rich can mostly be found pedaling furiously around his local trails, or slightly further afield in the Quantocks, the Mendips or Exmoor. 

Current rides: Merida One-Forty 6000, Banshee Paradox

Height: 175cm

Weight: 68kg