Carrera Vulcan pedal assist

Hi,does anyone know how the pedal assist on a Carrera vulcan actually works? Thank you.

Yes, I do. It's optical. It has two castellated rings, one attached to the pedals and one to the chainwheel. There are 5 stiff springs between them. They overlap each other do that their slots line up. As they rotate, the sensors can get the speed from the rate of slots passing. The force on the pedals makes one ring move relative the other, so the sensor can see how hard you're pedalling from the length of each slot.

 

The sensor suffers some problems, mainly related to the seal between the two outer parts. The seal degrades or gets jammed by dirt, which breaks the stop on the sensor, so it goes around with the pedals, which stretches and breaks the wires. Also dirt gets in and compromises the optics. You can also break the sensor or pull the wires if the chain comes off.

 

I made a thread a few years ago, maybe in my other account, with pictures and a description, which you can find if you do a Google search of the forum.

Thanks for confirming what I thought,I bought a Vulcan supposed to be faulty battery . Been working on it , problems I've found,the sensor ripped off as you said , the drive chain warped so chain falls off , the cassette free wheel free wheel teeth sheered !!!! Resoldered the control got rid of the e42 error .I've got the hub parts for the freewheel so that's not an issue but I was wondering what the best option for me is.Thank you for helping me.

Just sorted the drive chain problem reassembled the pedal sensor grid etc but was sure to bare in mind all the locating lumps so no wobble ,I've lost all the little shim washers though,must replace them.

I'd replace the controller, LCD, cranks with torque sensor with conventional ones. The electrics are about £80. The cranks are up to you. You can still use a conventional pedal sensor with them if you get the right type, but you can save a lot of weight and get a double or triple chainwheel on the front if you want. The motor is quite good, so worth keeping, and I believe that the battery will work with the new stuff, but check just to be sure that you get the normal viltage on the two main wires with nothing connected.

 

There's a thread somewhere about other people, who did this conversion.

Your right ,but wouldn't you lose the torque feature, out of curiosity the crenalated rings are they set open or closed. I'm going to look

At the threads you suggested now . Have you ever worked on a brose motor.

https://www.pedelecs.co.uk/forum/threads/carrera-crossfire-vulcan-torque-sensor.30490/

Thanks once again you've really helped ,even answered questions I would have asked ,I did try to search but got bogged down with information.

https://www.pedelecs.co.uk/forum/threads/carrera-crossfire-vulcan-torque-sensor.30490/

Well I thought it only right to tell you how I got on ,I had to swap the free wheel and freewheel plate from another broken motor ,I cleaned the display terminals resoldered the sensor ,moved the wheel and it registered,now I've got to make a bracket for the broken sensor,I'm really chuffed,thanks for you help.