Why We Chose the Maxon BIKEDRIVE AIR S for Our eMTB

When we set out to build an eMTB that felt like a real mountain bike — not a motorcycle with pedals — the motor choice was everything. After eighteen months of testing, we chose the Maxon BIKEDRIVE AIR S. Here's why.

The Problem with Mainstream eMTB Motors

Most eMTB motors on the market today were designed with a commuter-first mentality. The Shimano EP8 and Bosch Performance CX are excellent units, but they share a common philosophy: maximum torque, aggressive engagement, and a ride feel that constantly reminds you there's a motor between your cranks. For cross-country and trail riders who value the organic connection between pedal input and wheel output, that's a problem.

The Bosch CX delivers 85 Nm of torque and weighs 2.9 kg. The Shimano EP8 is lighter at 2.6 kg with 85 Nm. Both are proven, reliable, and well-supported. But both also have a characteristic "on-off" engagement that experienced riders notice immediately — especially on technical singletrack where subtle power modulation matters.

Why Maxon Was Different

Maxon comes from a different world entirely. Their motors power Mars rovers, surgical robots, and precision industrial equipment. The BIKEDRIVE AIR S weighs just 1.9 kg and produces 55 Nm of torque. On paper, that looks like less. In practice, it's a revelation.

The lower torque figure is deliberate. The AIR S uses a concentric motor design with virtually zero drag when unpowered, meaning the bike pedals like a normal bike when the motor is off or the battery dies. The power delivery is progressive and eerily smooth — there's no surge, no lag, and no abrupt cutoff at 25 km/h (or 20 mph in the US market).

Real-World Trail Performance

We tested the AIR S extensively on our local trails around Taichung, Taiwan — steep, technical, and humid. The lighter motor weight translates directly to better handling in tight switchbacks and more confident manuals and bunny hops. The Q-factor (pedal stance width) is narrower than both Shimano and Bosch, so your feet sit in a more natural position.

Range with a 540 Wh battery averages 60-90 km depending on terrain and assist level, which is competitive with heavier systems running larger batteries. The efficiency of the Maxon unit means you get comparable range from less battery weight.

The Bottom Line

We chose the Maxon BIKEDRIVE AIR S because it aligned with our core philosophy: the bike should feel like a bike first. The motor should enhance the ride, not define it. For riders who want electric assist without sacrificing the soul of mountain biking, we believe this is the right motor — and every test ride confirms it.