- Hello my fellow bike world People
- In this blog post I will be explaining assembly issues that can occur while making e-bikes with PAS or better known as pedal assisted cadence sensors.
- Recently e-bikes are becoming very popular with a wider audience of people because of their obvious benefits in every day use, transport or doing sports. At first these bikes were very expensive and bought only by real enthusiasts, people who are prepared to spend a lot of money on their bicycles. As a bike industry expert I see that now with these bikes gaining popularity a need is shown to make entry-level e bikes for average buyer who is looking to benefit from the assistance of 250W motor on his bike.
- Thus e-bikes with front and rear motors as an economic solution came to be very popular. In order to make these bikes certified pedelecs they have to be mounted with PAS sensors.
- Purpose of these sensors is to read the direction of the BB spindle movement, or to explain in a simple way if you are turning the pedals to start riding the bicycle. If you start turning pedal to propel you forward then it gives the signal to the e-bike’s controller which starts the motor to assist you. In other case if you stop pedaling or start turning pedals in reverse it will send the signal to the controller to cut the power to the motor thus allowing you to stop or slow down.
- There are two main types of these sensors.
- Ones that are mounted on the right side under the right cup of the bottom bracket.
- Second version mounted on the left side and mounted by pressing in the left cup. There are some versions on the market now that are pressed in the right side cups as well.
- Because these sensors shape and size hasn’t been standardized they come in a big variety of different models and systems. So when trying to develop this kind of e-bike or to service it one must be very careful about this part of the bicycle.
- First you must think if it is left hand or right hand sensor. In case you get this wrong the sensor will read the direction of the rotation in opposite way leaving you turning the pedals backwards to start the motor assistance. So very important point to look after.
- Secondly you must think about the clearance between the cups and cranks. Sensors range to be mostly from 5 top 8 mm thick and can often collide with the cranks. If this happens the sensor wont work or will be damaged by the pressure when assembling the left crank. To avoid this you must be careful about the spindle length of your bottom bracket, both on the right and left side.
- Third, in case of sensors that are pressed in the cups, you have to check the compatibility of the sensor with the cups as well as with the diameter of the spindle. There are some sensors with parameters that are not standard in cup width so you can’t press them in the cups thus they are not fixed and unusable.
- Fourth, one has to think about the electronics part and check the cable length and plug compatibility with the controller.
- So in conclusion a really tricky part to which you must pay attention and think about the issues mentioned before starting work.
- Thank you for reading and be sure to read more about this and other topics here at 128.bike
- If you wish to see the video : https://www.youtube.com/watch?v=8avJ_kmI0og
