Custom torque sensor

Get a customized torque/cadence sensor to fit perfectly into your project. We make custom sensors to your specifications for mid-drive, hub motors, and many other configurations. Want to know more? Read about the step-by-step process below and get in touch with our experienced product engineers to discuss how we may help.

STEP-BY-STEP CUSTOMIZATION PROCESS

STEP 1 – SPECIFICATION

Together we specify the customized torque sensor. Using our template or your existing design definition documentation. This covers the key features of the sensor.

FORM: Mechanical outline for the stator and rotor PCBs. Mounting holes. Connector and location. Tolerances.
FUNCTION: Electrical interface. Protocol. Torque range. Cadence resolution. Temperature range. Water/oil proofing.
TEST: How to test the sensor. Any fixtures or jigs required.

With this in place, we start the design process for your specific sensor.

STEP 2 – PROTOTYPE MANUFACTURE

The sensor PCBs are designed based on the agreed specification (we like to receive simple DXF files from you on the agreed PCB shapes). Any remaining questions are resolved in this process. You will get a final 3D (STEP) file for verification.

We manufacture the prototypes (rotor and stator PCBs). This process typically takes 3-4 weeks.

STEP 3 – TUNE, TEST, AND SHIP

When we have the first prototype PCBs, the process we call tuning starts. This is where we optimize the sensor for power consumption, airgap range, cadence performance, torque range, electrical interface and protocol, update rate, averaging, etc. When we receive your metal part(s) we bond the strain gauges and make sure the sensitivity is right.

As part of this process, the sensor is tested to the specifications agreed upon. For this, we need a setup to apply the torque range specified. Depending on the shape of your system we may ask you to provide this. The same applies to testing cadence. We have some fairly flexible testing systems which work for many cases, but your situation may be different.

Once we are happy with the sensor, we will typically arrange a video call with you to show how it works before shipping it. This is when your testing process starts.

MECHANICAL PARTS

The metal body (typically aluminum or steel) used to measure the torque would normally be some existing part of your design. We can assist you in finding the optimal placement for the strain gauge(s) and how to shape the metal for best performance. We have seen most of the common ways to do e-bike drive trains already, and that is likely similar to what you are trying to do.

Preferably, you do the design, manufacture, and supply of the mechanical parts including the metal body. If needed we can also arrange to have that designed and manufactured locally.

START THE PROCESS

Get in touch to discuss how we can help you build the ideal customized torque/cadence sensor for your project. We do not have public pricing, so an NDA (Non-Disclosure Agreement) is needed before we get to that. Don’t let that hold you back as the pricing is very competitive and you may be surprised by how inexpensively we can do a 100% custom torque sensor design for you.

FAQ

What does a torque sensor do?

The information about the force used when pedaling is immediately sent to the motor controller. The controller calculates how much electrical power is needed for support, depending on how hard you pedal and the assist setting used.

How does a torque sensor work?

A good torque sensor system usually uses strain gauge technology to measure the force that is applied. A strain gauge converts a twist or a bend into electrical resistance: When the sensor is exposed to a small twist, the resistance in the strain gauge increases or decreases, and that information tells how much force has been applied. A number of other torque sensor technologies exist.

What happens if I have no torque sensor on my e-bike?

An e-bike without a torque sensor will typically respond to cadence only. Typically, also with a larger delay. This causes an unnatural ride experience and makes it more difficult to control the bike. This is a significant safety concern for all e-bike types. A torque sensor is required for any performance/sport-style e-bike.