Newly unveiled electric bike motor is ‘world’s lightest, most efficient’

TQ, the German force behind some of the lightest and quietest e-bike motors on the market, just took a leap forward – again. Barely weeks after debuting the lightweight HPR60 e-bike drive system, the company has introduced the HPR40, now claiming the title of the lightest and most efficient mid-drive motor in the world.

Tailored for road and gravel e-bikes, the HPR40 clocks in at just 1.17 kg (2.6 lb). That means it has slashed nearly half the weight of the previous HPR60, which weighed 1.92 kg (4.2 lb).

Despite being smaller, it still delivers a respectable 40 Nm of torque and up to 200W of peak power, making it ideal for riders seeking subtle assist rather than brute force. This isn’t about raw horsepower; it’s about efficiency and seamless integration.

Don’t expect to see it on the next 750W Lectric or Aventon, but look for it on higher-end gravel and road e-bikes where riders are looking for a modest boost instead of a powerful burst.

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Unlike motors that have been rebadged from their original use on mountain bikes or commuters, TQ designed the HPR40 from scratch for lighter frames, aiming to remain nearly invisible on a bike’s bottom bracket and with controls hidden inside the handlebar. The result is a drive system that blends into the bike like a whisper, offering performance without the bulk.

At the heart of the HPR motor is TQ’s Harmonic Pin-Ring Transmission, which is a refined drivetrain rearranged to live fully inside a bike in place of the bottom bracket. This clever design eliminates noisy gears, reduces friction, and lets the motor engage instantly with zero lag. While that might sound like many mid-drives we regularly see from manufacturers like Bosch, TQ’s is so small and so deeply integrated that it’s barely visible to a casual observer.

The HPR40 pairs with a 290Wh battery that weighs just 1.46 kg (3.2 lb) and is hidden inside the downtube. There’s also a water bottle-sized 160 Wh range extender available, keeping total system weight under 2.7 kg (6 lbs). That’s one of the lightest fully integrated e-bike systems out there.

Control comes via a hidden handlebar remote hidden under the handlebar tape, and a sleek end-cap LED display keeps essentials in view without disrupting aesthetics. This stripped-down interface reinforces TQ’s philosophy: get out of the rider’s way. Or as New Atlas humorously described it, “it’s almost as if the company is daring riders to start a fresh round of mechanical doping scandals.”

TQ’s HPR40 isn’t just a fancy new drive system in a display booth, it’s already built into the new Canyon Endurace:ONFly, a sub‑10 kg (22 lb) e-road bike that tips the scales at just 9.9 kg. The Endurace:ONFly marries TQ’s whisper-soft assist with Canyon’s aerodynamic finesse, offering riders a bike that feels analog but rides electric.

The HPR40’s high torque density means riders can double their pedaling output with a modest 200 W boost. That translates to better climbs, longer rides, and a natural ride feel, all without the compromises of heavier systems. Considering that many riders can put out around 200W of constant power by themselves, the effect is like having a tandem rider along helping out, except that he only weighs 6 pounds.

The move shows that not every drive maker is merely chasing horsepower and torque figures. Instead, by merging elegant design, noticeable yet natural power, and light weight, TQ is proving that electric assistance doesn’t have to scream. It can whisper.

Electrek’s Take

Here’s the real story: the HPR40 isn’t just a technical footnote, it’s a signal. It shows that electric bike engineering is transitioning from brute force toward a future that also includes invisible, intuitive power systems. For riders chasing the delicate line between analog feel and electric assist, this is a breakthrough.

And considering that many riders are reaching an age where their mind wants to do the kind of rides that their body might no longer be capable of, systems like these can keep those riders in the saddle for longer. That’s many more years of keeping the good times rolling (and keeping the body young by continuing regular exercise).

Now the question is whether other brands will follow suit. Will we see this ultra-light motor trickle down into commuter e‑bikes or adventure-ready gravel rigs? If so, the day when an e‑bike feels exactly like a bike, but gives you a little assist when you need it most, just got much closer.

TQ is playing a long game: subtle, smart, and purpose-built. The HPR40 is merely the first move, and if this is any indicator, the next wave of e-bikes may feel less electric and more… old school?