Torque sensor BB and MPe



For MPe computer it’s possible to add a pedalling force sensor (bottom bracket with torque sensor). Thanks to this, we can add pedaling assistance to each HUB motor and to each controller, based on the currently applied power by the cyclist.

This is the only solution that was created in Europe, which allows to add such functionality to electric bicycles of the “do it yourself” type 🙂.

In this article you will find (SHORTCUTS – by clicking on a particular chapter, you will go directly to a given part):

5 invaluable possibilities

of the torque sensor in combination with MPe

Anyone who has had the opportunity to ride with a bottom bracket with torque sensor knows how amazing and fun it can be.

How does the torque sensor work with the MPe computer?
MPe will sense the speed of rotation of the cranks and the torque on the pedals/cranks as the cyclist’s power and converts them into a correspondingly increased (adjustable) power of the electric drive.

  1. Real cycling sensations. The feeling of riding is more like riding a bicycle.
  2. Individual selection of assist level power (it is adjustable) depends on the cyclist. It is the cyclist who uses his pedaling power to determine the power of the assistance, and thus the speed of the vehicle. There is no effect, as in a regular (cadence only) support, that the bike is chasing a certain speed.
  3. Better control over the speed of the bicycle. The bike will never go faster than we can pedal.
  4. The ability to start from standstill, without a throttle, just by pressing the pedal.
  5. Better health and fitness. Thanks to the torque sensor, we mobilize the body to exercise. Of course, we ourselves decide how much this fatigue should be. It happens through the force put into pedaling and the selection of the appropriate power assist level. The effort can vary from very intense to minimal.

NOTE: with the bottom bracket with torque sensor, you can also use the cadence sensor only (PAS – Pedal Assistant Sensor). In a bicycle, we therefore have two types of assistance solution. The eRider T9 bottom bracket itself has a cadence sensor with 18 magnets, you do not need to add it. In the MPe system, you can set several assist levels for the torque sensor, and leave a few using only the cadence sensor. The user has the freedom of choice and the ability to change the method of assistance while riding.

Our experience and feelings

with a human power based support

1. We had the opportunity to test, the eRider T9 bottom bracket with torque sensor, compatible with the MPe computer, at the e-bike’s fan expo in Żyrardów on the Kuba’s bike from the Elekrto Rider channel (BLDC 36v48v 250w 6A controller).

2. The torque sensor can be found mainly in factory bikes with a mid drive. We have already had the opportunity to test this type of equipment: SHIMANO STEPS E7000 TEST RIDE – KELLYS THEOS 50

3. Another alternative comes here with the popular TSDZ2 drive. After uploading the open firmware, the sensations on this support with a torque sensor are very similar to those from factory bikes.

Ana from and mid-drive TSDZ2
Ana from and mid-drive TSDZ2

What to do to be able to add

the torque sensor to the electric bike?

1. Have a wheel motor (HUB)
2. Have an MPe V6 computer

Case of the main module the MPeV6 computer
Main module - MPe V6
MPe V5 computer case
Archive main module - MPe V5

For those who have the MPe V5 motherboard version, it will also be possible to add a torque sensor. You will need to add an extra 12V power supply. Of course, in our store you can buy the V6 motherboard separately. 


  • Mainboards in our store are now available with the latest firmware (from version v6.008) working with the torque sensor BB.
  • If you are just buying an MPe computer (after December 6, 2020), you already have screw connectors/terminals for the torque sensor BB on MPe motherboard. All you need to do is connect to them with cables from the torque sensor (you will receive the cable together with the torqe sensor bottom bracket). Motherboard version: from to V6.5
MPeV6 (V6.5) motherboard version
MPeV6 (V6.5) motherboard version
  • However, if you bought an MPe computer (before December 6, 2020), you need to solder yourself to the MPe motherboard with wires. You can do it yourself (details below). Motherboard version: up to V6.4 inclusive

3. If you have firmware version from v6.007 and lower, please update it to the latest version, starting with v6.008 (version already available on our blog: HERE). To do this, it is necessary to have a programmer, which can be purchased in our store:

Basic programmer for updating the firmware
Basic programmer
Universal programmer will work for MaxiColor 850C display
Universal programmer

How to reprogram your firmware to the latest version is described here:

4. Purchase a bottom bracket with torque sensor – eRider T9. At the moment, the MPe computer will only work with this type of BB. This BB is for a standard BSA-threaded version. You can buy them in different widths, usually 68mm or 73mm. There are also other widths: 80, 83, 100 and 120mm.


Its advantage is to lead the cable in such a way that you do not need to drill a hole in the bicycle frame. Its second very important advantage is the fact that it measures the torque on both cranks, and not only on the left, like other bottom brackets. The third very important feature is the fact that the bottom bracket has an integrated cadence sensor with 18 magnets – so it is very accurate.

Select here a 4-claw chain adaptor, with BCD (pitch diameter for chainring mounting holes) 104mm. The chainrings should be unscrewed from the old cranks and screwed to the chain adaptor sold with the sensor. There are two 4 and 5 claw adaptors to choose from. You should choose these 4 claw chain adaptor with the 104mm BCD. (Alternatively, the chainrings and screws can also be purchased separately). For this 4 claw adaptor, 1 – 3 chainrings can be attached (individually, depending on the rider’s needs).

Torque sensor for MPe computer - eRider T9
Torque sensor BB for MPe computer - eRider T9

5. Purchase other cranks with square taper where the right crank is without chainrings, e.g. from the SHIMANO STEPS E6000TSDZ2 or BAFANG drive. (In my opinion, the Bafang cranks are less ergonomic, because they are very straight and the shoe hooks onto the crank around the ankle. Shimano cranks have very good ergonomics, according to customers, they are solid and available on market for reasonable price.). You can also use the cranks of an ordinary bicycle, but the right crank has to be cut off (e.g. with an angle grinder) the attachment of the chainrings. Also cranks from CYC X1 PRO gen 2 motor with torque sensor will fit.

Cranks: Shimano Steps E6000, Bafang, TSDZ2 and MTB for torque sensor + MPe computer
Cranks: Shimano Steps E6000, Bafang, TSDZ2 and MTB for torque sensor + MPe computer

6. Solder the wire from the sensor to the soldering pads of the MPeV6 motherboard. 

NOTE for motherboard version up to V6.4 inclusive: applies to MPe computers purchased before December 6, 2020 (current MPe motherboards have screw connectors/terminals, and you only need to plug into them). To do this, disconnect all cables and remove the motherboard from the housing.

These pads are marked as:
• 12V – power supply [mostly red wire]
• GND – ground [usually black wire]
• PAS – cadence / crank speed signal [usually green wire]
• A3 – pressure / torque signal [usually white wire]

Places where the wires from the torque sensor should be soldered
Places where the wires from the torque sensor should be soldered
Soldered wires from the torque sensor in the MPeV6 main board
Soldered wires from the torque sensor in the MPeV6 main board

FAQ - frequently asked questions

We also recommend reading the article with frequently asked questions:

Episode with technical details

Subtitles in English (enable the option in the settings)

Watch the episode
how to connect the sensor to the MPeV6 motherboard

Subtitles in English (enable the option in the settings)

In this episode, I cover how to connect to the MPeV6 motherboard for these two versions:

  • from V6.5 (available for sale from December 2020)
  • up to version V6.4 inclusive (available for sale until December 2020)

Components purchase sources

1. ERider T9 bottom bracket with torque and cadence sensor:

2. Purchase of cranks where the right crank has no chainrings, e.g. from TSDZ2.

The offer comes from Aliexpress, from which we also bought sensors and are currently testing them. We would also like to point out here that by choosing to purchase from the above source, you have the option of supporting us financially (the so-called affiliate link). You don’t lose a single penny on it, but we get a modest penny, for example for running this blog 😊👍.

More details soon.

Stay tuned 😊:

FB group e-BIKEL-owcy technically about electric vehicles

FB group „e-BIKEL-owcy"

In the Facebook group we exchange experiences and comments on electric vehicles

Leave a Reply

Your email address will not be published. Required fields are marked *