With the HPR 50, TQ landed a real hit a few years ago. Never before had an e-bike motor been so small, so quiet, so compact and so natural to ride. Minor weaknesses in power and derating have now been compensated for. the new HPR 60 (tested by our sister magazine BIKE) with the same form factor.
The ideal opportunity for TQ to add a new drive to its portfolio. The new HPR 40 is significantly smaller and another 800 grams lighter than the already super-compact HPR 50/60. With 40 Nm torque and up to 200 watts of power, the 1200 gram motor should provide the ideal support for fast road and gravel bikes, because it is visually and technically as discreet as possible and hardly detracts from the slim silhouette of these bikes. Is this the breakthrough of electric motors in the segment with racing handlebars? We have all the details!
This is the TQ HPR 40
- Maximum torque: 40 Nm
- Maximum power: 200 watts
- Motor weight: 1170 grams
- Support factor: 100 per cent
- Battery capacity: 290 watt hours
- System weight: 2700 grams
- Driving modes: Eco, Mid, High
- Range of use: Road, Gravel, Cross-Country
Natural driving feel and Harmonic pinring
Like its big brothers, the HPR 40 is designed as a mid-motor, which means it sits in the bottom bracket of the bike. This ensures the most direct response behaviour possible, a clean weight distribution and makes high dynamics possible even in a compact installation space.
The motor, which is not even the size of a fist, relies on TQ's patented harmonic pin ring gearbox, which is located on the outside of the motor housing. The advantages that we already know from the HPR 50 and HPR 60: No pedal travel, maximum direct response behaviour, extremely quiet riding noise and a Q-factor like a classic bottom bracket. All of this should benefit the HPR 40, especially on gravel and racing bikes, where the motor should play as discreet a role as possible.
Operation, display and support factor
The display and controls are also discreet. The HPR 40 simply shows the battery status and riding mode on a mini LED display in the handlebar end. The motor is operated via buttons located under the handlebar tape. In combination with the extremely slim silhouette of the motor and battery, the finished bike is barely recognisable as an e-bike.
The assistance of the HPR 40 is a maximum of 100 per cent. This means that the motor only adds as much power as the rider pushes into the crank. This is intended to level out differences in performance between groups of riders, especially in hilly terrain. On flat sections, the slipstream in the group takes over this task, according to the manufacturer. And speaking of slipstream: Above 25 km/h, the HPR 40 should be able to be pedalled completely without additional resistance. Based on our experience with the HPR 50, this is certainly a credible claim.
Bike weight and range
The discreet assistance should make long tours possible despite the small battery. TQ assumes 100 kilometres and 1200 metres in altitude for an 80-kilo rider with the highest level of support and almost double the range in Eco mode. Practical: Additional electronics such as the gears or a light can also be supplied with power via the main battery of the E-System. There is no need for a power meter because the drive measures the rider's power anyway and transmits it to standard bike computers via ANT+, for example.
With a system weight of 2700 grams for the motor, battery, displays etc., the HPR 40 is extremely light and should make wheel weights of around 10 kilograms realistic on the road. According to the manufacturer, this makes the bike ride almost like a conventional race or gravel bike, only with an additional tailwind uphill.
Details such as support and many other functions can be controlled and fine-tuned via TQ's well-known app. Like the previous motors, the HPR 40 is produced by electronics specialist TQ itself, mainly in the small parts, at the company's site on the Bavarian Ammersee. This makes the lightweight minimalist one of the absolute locals in the racing bike area around Munich.
Assessment of the HPR 40
The lightest mid-motor on the market impresses with its extremely low weight. The technology with harmonic pin ring appears to be closely modelled on the larger drives from TQ and is tried and tested. Riding feel and response behaviour, pedalling resistance and performance should be convincing. Will this really be the breakthrough for lightweight e-bikes in the gravel and even road segment? We remain curious. - Adrian Kaether, Editor Test & Technology
Adrian Kaether
Editor
