FAQ – TQ E-Bike

Below we have briefly and concisely summarized the answers to many frequently asked questions (FAQ). The answers are arranged according to topics and products. If your question is not listed, please feel free to contact us directly at any time.

Are 50 Nm really enough?

YES! We use the energy as efficiently as possible, so we don’t need an excessive amount of Newton meters. Our TQ-HPR50 drive system supports exactly as much as necessary and exactly where you need it and it is virtually invisible. With this minimum weight and integration space we are providing an uncompromised riding experience. You decide how you want to ride it. With the 50 Nm you will ride your e-bike just like an analog bike but more, further, higher…

How can the TQ-HPR50 reach its torque within such a small space?

The trick is our patented harmonic pin-ring transmission. In most commonly used e-bike motors, power is transmitted through respective cog wheels where only few touchpoints are engaged at a time, while the rest of the gears are usually not engaged at all. This results in a less efficient and indirect power transmission. This kind of gearbox usually takes most of the space in mid-mounted motors.
With the harmonic pin-ring gear, all teeth of the gear are engaged at the same time and are used for power transmission. As a result, the gearbox can be designed much more compactly and still easily reproduce the necessary reduction ratio (currently 1:17.5) in just one gear stage. With standard transmissions, this requires comparatively more space and gear stages.

Are there any other comparable transmissions?

No. In robotics, there are similar rotationally symmetrical transmissions, also with low gear ratio (e.g. cycloidal or harmonic gears). However, their use always implies at least one or more limitations such as:

a. Significantly lower efficiency
b. Non or only small hollow shaft (otherwise usable installation space around the central axis)
c. Wide axial design
d. High cost

The harmonic pin-ring transmission developed by TQ is not subject to these limitations.

How efficient is the TQ-HPR50 drive unit?

The electric motor in the TQ drive unit was designed specifically for its intended application and achieves an efficiency of more than 90%. The optimized coordination of drive unit, battery management system and power sensor technology allows for maximum yield of the battery capacity. However, the efficiency of the drive unit is only one link in the efficiency chain. The efficiency of the overall system, consisting of all components such as the drive unit, battery and their software, is much more decisive for the range that can be experienced. The entire software and hardware of the HPR50 system were completely developed and produced by TQ, so we can ensure that all components are optimally matched and thus a very high system efficiency is ensured.

Do I have to pedal the e-bike motor when riding without motor support?

No. When riding without motor assistance, the HPR50-equipped e-bike behaves like an analog bike. The reason for that are specifically developed freewheel sprags which completely disengage from the whole motor and transmission.

How do we create the natural riding experience?

Instead of the using a commonly applied torque sensor, we’ve redesigned and patented our own force sensor. It measures the input variables: crank speed, crank acceleration and the forces of both pedal cranks independently. A specially developed algorithm uses this to control the motor and, in addition to seamless response, also enables the natural riding experience.

On top of that the new force sensor now takes up even less installation space and weight.

Are third-party chargers safe to use?

Our active charger communicates with the battery during the entire charging process. While doing that, it also checks various factors such as cell parameters, ambient temperature and many more. This allows us to optimize charging times and at the same time we can charge in a highly battery-friendly way. However, this also means that currently our batteries may only be charged with the respective TQ charger and no third party charger.

Can you increase the TQ e-bike systems battery capacity?

Yeah – with our range extender which weighs only 950 g you can add another 160 Wh. The range extender is as small and light as a full water bottle and fits perfectly in the specifically designed bottle cage. So nothing stands in the way of your extra-long e-bike rides.

How does the charging process work when the range extender is installed?

It is very easy. You just keep the range extender connected to the charge port of the bike and plug the charger straight into the range extender. Our software detects the range extender and then starts the charging process. However, the main battery will always be recharged first and then comes the range extender. This way you can always start your ride with a full main battery and leave the empty range extender at home in case you did not have not enough time to charge both.

How long does it take to charge the main battery?

It takes about 2-3 hours to charge the internal battery for the TQ-HPR50 e-bike system and to get ready for your next adventure.

What is the range of the TQ-HPR50 e-bike system?

The range mainly depends on the following factors:

  • What kind of terrain you are riding on
  • The level of assistance you are using
  • The total weight you are carrying
  • External factors such a temperature

Our software accounts for these and many other factors and calculates the remaining battery range based on your specific rider profile. This is then shown on your fully integrated display and constantly updated.


Our 75 kg test rider has already climbed 1,200 hm and ridden 50 km in the steepest terrain at the highest support level. On flat terrain and with less support, however, he has also managed to ride more than 100 km.

Can I connect my smartphone with the TQ-HPR50 equipped bike?

Yes, via ANT+ you can connect your bike, like any other sensor with the bike computer or with ANT+ compatible watches. In addition, you can connect your bike via Bluetooth with the TQ E-Bike app and thus you can customize motor tuning, for example. 

What should I do if I see an error on the display?

An error shown on the display can have different reasons. You can find out the cause of the error display and what to do to solve the problem here.

Can I ride my e-bike with TQ-HPR50 system also with mullet setup?

The way the speed is measured for the TQ-HPR50 system is by multiplying the pre-set rear wheel circumference by its rpm, as simple as that. So understandably, by changing the wheel size the actual speed and the calculation miss match and could possibly result in an illegally fast cut-off speed. The anti-tinkering regulations are very strict about the cut-off speed for e-bikes. To make sure that TQ-powered bikes are compliant with the allowed maximal speed, the software is set for each bike’s “factory setting” wheel size and cannot be modified. We are aware that this is not an ideal situation for the smaller rear wheel lovers. But, for example, by changing the rear wheel from 29 x 2.35“ to 27.5 x 2.6”, the cut-off speed will only vary by less than 1 km/h or 0.6 mph, which we find as an acceptable trade-off.

Can I connect lights to my TQ-HPR50 powered e-bike?

You can equip your TQ-powered e-bike with lights made by Supernova and Lupine. Suitable adapter cable with Micro A/B connector and the TQ-Smartbox is needed. Both can be obtained at your local dealer. We strongly advise, to have the lights connected to the TQ-HPR50 system at your local dealer. The activation of the power output for the lights is done through the Dealer Service Tool which is made for in-shop use only and is made specifically to protect the system from misuse. The maximum power for the lighting (front and rear light) should not exceed 26 W at 13,2 V.

Please check which light is compatible with the TQ-HPR50 system directly at the respective manufacturer Supernova and Lupine.


What factors influence the e-bike range?

The e-bike range is determined by the battery capacity. If necessary, the battery capacity can be extended with the range extender.

The range depends on the e-bike system, e-bike rider and the surrounding environment. The following factors, among others, lead to different possible ranges:

  • Altitude gain
  • Average rider power
  • Proportion of the ride above the maximum assistance speed
  • Individual support level (can be customized in the TQ app)
  • Total ready-to-ride weight (e-bike + rider + equipment)
  • Number of starts from standstill
  • Tire pressure
  • Tire tread
  • Road conditions
  • Ambient temperature
  • Wind speed
  • Connected accessories (light, electric shifter, ...)



Our 75 kg test rider has already managed 1,200 hm and 50 km in the steepest terrain at the highest support level. On flat terrain and with less support, however, he has also covered more than 100 km.

How does the TQ-HPR50 e-bike system calculate range without app connection?

Our software calculates the remaining range based on your previous trip. This is then shown on the display and constantly updated. We calculate the range based on the previous energy demand depending on the individual ride mode that is customizable via the TQ app.

A standard range is initially displayed for each ride mode. This is also initially displayed when switching to a different ride mode. During the ride, the range is continuously adjusted by the range algorithm.

How does the TQ-HPR50 e-bike system calculate range in a TREK e-bike with the connected TREK Central app?

A robust algorithm calculates the estimated range for each ride mode. That takes into account the, the wind, the topography, the weight of the rider and much more. This feature requires the app to be connected to the bike.

The range shown in the TREK app may differ from the range shown on the TQ-HPR50 e-bike display.

What do I have to do before riding my new e-bike with TQ-HPR50 for the first time?

It is very important that you fully charge the battery before your first ride. Only then the battery and all functions are ready for use. 


Please contact us if you need information about TQ E-Bike, products or services.


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