The Maxon Bikedrive Air is the sleek, neatly integrated mid-motor behind what has been billed for years as the world's lightest full-suspension electric mountain bike, the 14.8-kg (32.6-lb) Thömus Lightrider E Ultimate. Maxon's all-new Bikedrive Air S won't shave any more ounces off that lively fully sprung steed, but it will triple its original torque without adding significant weight.
That means a new generation of ultralight e-MTBs that are ready to rocket off the line and mountain-goat up rock-strewn steeps with ease.
Prior to getting into the ebike market, Switzerland-based Maxon honed its craft on tiny precision micro-drive systems for industries as demanding as aerospace, medical and robotics. Its motors have powered everything from the robotic arms that NASA's Perseverance rover used to process soil from Mars to the "world's first miniaturized robot-assisted surgical device."
Expertise in small, ultra-performance e-drives proved a natural for transitioning into the booming mid-motor ebike drive market, and Maxon introduced the "light and invisible" Bikedrive Air in 2021. Besides helping Thömus hit that sub-15-kg (33-lb) floor for full-suspension e-MTB weights, the Air drive quickly became the centerpiece of the exceptionally lightweight 10.7-kg (23.6-lb) Cipollini Flusso electric road bike and the sub-16-kg (35.2-lb) Transalpes E1 e-MTB.
That original Bikedrive Air helped bike manufacturers hit those low weight points by delivering 220 watts from a total system weighing just 3.5 kg (7.7 lb). At first that might sound rather hefty in comparison to the 2- to 2.5-kg (4.4- to 5.5-lb) e-drive weights competitors advertise, but Maxon's figure includes the 250-Wh battery pack, whereas others are for the motor drive alone. The Air motor drive unit itself weighs just 1.9 kg (4.2 lb).
On the downside, that original Air drive put out just 30 Nm of torque, not bad for 2022 but well short of the 100-Nm figures that have taken over the market this year, even after considering that Maxon had previously tuned the Air up to 40 Nm (and 250 W).
The new Air S drive, which Maxon premiered at this summer's Eurobike show, pinches that gap near closed, beefing up in output while still boasting a total system weight of just 3.8 kg (8.3 lb).
Most of the added weight comes from the battery pack, which increases in capacity to 400 Wh. The motor tacks on just 100 grams (3.5 oz) up to an even 2 kg (4.4 lb) while spiking max torque to 90 Nm, triple the Air's original 30 Nm. Available power peaks at 620 watts, also close to triple the Air's original mark.
A quick comparison to other new mid-motors from Eurobike 2025 (not including battery weight): The 850-W/105-Nm Mahle M40 motor weighs 2.5 kg (5.5 lb); the 350-W/60-Nm TQ HPR60 weighs 1.9 kg (4.2 lb); and the 750-W/105-Nm ZF Centrix weighs 2.5 kg (5.5 lb). So the Air S drive remains on the lightest end of the spectrum while putting out robust torque and power figures. Maxon calls it the "lightest full-power ebike motor."
"Our aim was to combine maximum power density with efficient, precise control and a compact design. This is precisely where our strength lies – whether in satellites, airplanes, Formula 1 racing cars or e-bikes," summed up Maxon head of R&D, Dominik Stockmann.
As for the physical size part of that "compact design" equation, i.e. Maxon's claims of "invisibility," the Air S follows the Air in featuring a configuration unique from other ebike drives. Instead of packing all its motor and gearing hardware into a single cylinder or oblong bottom-bracket housing, Maxon installs the brushless internal rotor motor and planetary gearbox in a perpendicular pair of cylinders.
The split-cylinder design appears to slim the bottom bracket even more effectively than single-cylinder mid-motor packages, but the separate motor cylinder extending upward does swell the lower down tube just above/fore of the cranks. Still, both the Air and Air S do seem capable of disappearing away fairly subtly within the frame.
Maxon complements the cleanly integrated mid-drive with a down tube-enclosed battery pack. In addition to the 400-Wh unit, the company plans to launch a longer-range 600-Wh battery and a 250-Wh bottle cage-compatible range extender. Air S-powered bikes won't charge in a magical 15 minutes, unfortunately; riders can expect a 0-to-80% charge to take a full three hours.
While electric mountain bikes gained the most attention among ebikes utilizing the first-generation Bikedrive Air, Maxon is pushing the second generation (the Air S) as a versatile solution for various bike segments.
"What makes the Air S special is not only its unique weight-to-power ratio but also its versatility," said Maxon ebike chief Volker Stützinger. "For mountain bikes, gravel bikes or urban platforms: The system's properties make it universally applicable in many bike categories."
The first Air S-powered bikes we've seen set rubber to public ground are, however, mountain bikes. The all-new Ocelot from Dutch brand Instinctiv brings Maxon Air S power to the electric trail MTB category, offering front/rear suspension breakdowns between 160/125 mm and 170/145 mm. The lightest model checks in at 18.7 kg (41.2 lb), and prices will start at €8,010 (approx. US$9,350) when the bike hits the market in Q4 2025/Q1 2026. Instinctiv is taking preorders now.
As for Thömus, it will continue to sell the cross country Lightrider Ultimate E as the "world's lightest full suspension electric mountain bike," equipped with the 250-W/40-Nm Air drive that Maxon will continue to offer as a lighter, lower-power ebike solution. Thömus will put the more powerful Air S setup to use on the new Lightrider E Max, available as a lightweight XC or a cushier trail bike. The E Max will launch in late 2025 and is available for preorder now.
We'll stay on the lookout for the next round of new-generation Air S-powered mountain, gravel and urban bikes in the coming weeks and months.
Source: Maxon
