Mahle X20 lightweight e-bike drive gets lighter, smoother

Mahle e-bike drive systems just got substantially lighter thanks to the big weight savings in their new, more compact X20 hub motor. Already one of the most popular lightweight e-bike powertrains for road & gravel, the new X20 completely refines & modernizes Mahle (formerly eBikemotion) pedal-assist performance while becoming the “lightest e-bike drive system on the market” beyond its improved power: weight ratio.

Mahle X20 lightweight e-bike drive system

Mahle X20 lightweight e-bike drive system components

c. Mahle

The previous Mahle hub motor was probably already the most common drive system we’d find in lightweight road & gravel e-bikes. Combining a lightweight 250W engine in the hub of the rear wheel, balanced with a small 250W battery hidden inside the downtube of bikes from the likes of Cannondale, GT, Orbea, Rose, Scott, Simplon, 3T, Urwahn & Wilier (to name just a recent handful), it was a simple and unobtrusive solution that often didn’t even require major changes to those e-bikes’ analog analogues.

But now, the X20 hub is simply better all around.

It’s lighter, smoother, easier to get on & off the bike, better integrated, less obtrusive. Interestingly, it’s also a bit less powerful, giving an added benefit of longer ranges, too.

Tech details – What’s new?

Mahle X20 lightweight e-bike drive system schematic

The new complete Mahle X20 system now weighs just 3.2kg, down 300g from the X35. That’s why Mahle calls it the “lightest e-bike drive system on the market”. The smaller diameter hub itself drops even more weight than that, around half a kilo down to just 1399g, now that its weight also doesn’t need to include its axle or freehub.

Those are now both able to be pulled out as the X20 uses a more standard 12x142mm thru-axle interface, and now an interchangeable freehub body that brings compatibility with Shimano HG, SRAM XD-R & Campagnolo N3W cassettes.

Mahle X20 lightweight e-bike drive system, BB torque & cadence sensors

Mahle has upgraded the natural ride feel with a pair of new sensors measuring applied torque & cadence at the bottom bracket, to more smoothly ramp up pedal-assist support to match rider input thanks to smart “Artificial Intelligence” programming.

Mahle X20 lightweight e-bike drive system, hub rendering

The new X20 hub is still rated at 250W but its official toque output scales down to 23Nm at the hub (from 40Nm for the X35), which Mahle says equates to a 55-60Nm toque output from a mid-drive motor due to drivetrain losses. That’s still a good bit less than the 85Nm of a top-tier Shimano EP8 or Bosch Performance Line CX engine, but more comparable to their second-tier motors or the lightweight Fazua system.

Mahle X20 lightweight e-bike drive system, hub detail

Mahle’s thinking (and one we can agree with) is that the lower peak torque combined with narrower tires of road & gravel bikes and intelligent power management systems, actually delivers a much smoother pedal-assist without the jerky feel of more powerful systems.

The side benefit of lower peak torque output is that pedal-assist range with the same size battery increases as well, so you can ride your e-bike farther.

2022 Wilier Filante Hybrid stealthy carbon aero road e-bike, Mahle X20 hub motor

c. Wilier

The smaller X20 rear hub motor also gets rid of the external power wiring of the x35, instead adding a special dropout insert (black element between rotor & frame, above) with a keyed interface that automatically aligns a waterproof plug connector (with red seal, below left) when you insert the rear wheel.

2022 Wilier Filante Hybrid stealthy carbon aero road e-bike, Mahle X20 hub details

Compared to the separate wires and bolt-on axles of the X35 hub, this will make roadside flat repairs a much more manageable affair for anyone who can operate a regular QR thru-axle. A huge upgrade in user-friendliness!

2022 Wilier Filante Hybrid stealthy carbon aero road e-bike, Road Bike Connection Spring, photo by Rupert Fowler, frame detail

c. Bike Connection Agency, photo by Rupert Fowler

With wired connections more hidden inside, a smaller diameter hubshell, and a conventional looking thru-axle, the new X20 system simply disappears into stealthy e-bikes more than ever. Even when you know you are looking at an e-bike, it’s still hard to tell.

Mahle X20 lightweight e-bike drive system, Wilier integration

c. Wilier

Mahle has added their own new ANT + wireless Pulsar One cycling computer head unit design to interface with the X20 e-bike powertrain, while also pulling in your own external data from a heartrate monitor and / or power meter for ride tracking. They also have new optional E-Shifters which would allow riders to switch modes from the drops, and slimmed down their iWoc mode controller which can be integrated into the top tube, stem, or one-piece bar like on the Wilier.

There are also now three battery options to power the X20. The standard 250Wh internal battery carries over and they’ve added a larger capacity 350Wh internal battery for frames with more space in the downtube, plus the external Range Extender water bottle battery appears to have been scaled back to 185Wh to better fit in more e- bikes.

Mahle X20 Availability

Mahle X20 lightweight e-bike drive system, Scott Addict eRide

c. Scott, photo by Daniel Geiger

So far, we’ve already seen the new lightweight Mahle X20 e-bike drive system made available in Wilier’s endurance road Filante Hybrid & Scott’s latest Addict eRide e-bikes. We expect many more lightweight road and gravel e-bikes to join in with X20 soon.

Mahle.com

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