Cadence magnet help please

[jojocatgirl]

Hi there, I am really hoping someone can help me! I have had a Freego electric bike for 7 years, it's my daily main transport, so well used. Recently over the last year, it's working fine, then suddenly stops working. The first time this happened and after watching lots of videos, wires checked for connections, all good, I know that my sensor works, red light flashes when pedals move. I cleaned the magnetic plate, as recommended. But I noticed the magnetic plate is warped. If I adjust the distance to the sensor, sometimes it will start to work again. And be fine for a month or so, then the motor stops again. This remedy has worked several times. But this time this remedy is not working. Could the problem be the warped magnetic plate??, I cannot find any answers on this anywhere! I hope someone has some advice, I would be very grateful! I need my bike!!!

 

[Nealh]

The magnet disc needs to be approx. 1mm gap to the sensor head so if your disc is warped then yes one will see operation issues.
Often the magnet disc is held in place on the bottom bracket axle by small plastic splines incorporated in the disc. Check the disc is firm on the BB axle , that it can't be moved around it's axis by hand .
If it is slipping rotationally one can wrap some eletrical tape around the axle then slide the disc over the tape to try and secure it, alternatively simply buy a new magnet disc.
Most come with a new sensor head as well as a pair, cost about £10 on ebay.

 

[thelarkbox]

Yes a warped magnet plate could cause issues as the controller looks for a pattern of pulses to confirm pas activation and if warped disrupting the expected impulse pattern it could cause problems.

ebay/ali express a replacement sensor if you buy the same style you need only replace the magnet disk

 

[saneagle]

If you have the large diameter magnet disc, the one you have is difficult to find, but you can buy one of the large 12 magnet ones and press out every other magnet to make it work as a 6 magnet one. The one I had would only work like that.

As you can only buy the magnet disc with the sensor, you could just get an 8 or 10 magnet one and fit the whole lot if you don't mind pullubg the cranks and removingb the bottom bracket to fit it.

 

[jojocatgirl]

The magnet disc needs to be approx. 1mm gap to the sensor head so if your disc is warped then yes one will see operation issues.
Often the magnet disc is held in place on the bottom bracket axle by small plastic splines incorporated in the disc. Check the disc is firm on the BB axle , that it can't be moved around it's axis by hand .
If it is slipping rotationally one can wrap some eletrical tape around the axle then slide the disc over the tape to try and secure it, alternatively simply buy a new magnet disc.
Most come with a new sensor head as well as a pair, cost about £10 on ebay.

Thanks so much for your help. Tried the tape today, no job, but a new magnet disc is on order. Thanks again.

 

[Nealh]

Thanks so much for your help. Tried the tape today, no job, but a new magnet disc is on order. Thanks again.

OK worth a try with the tape some times.
Let us know how the new disc works out as we like a successful conclusion to a simple issue.

 

[jojocatgirl]

Sorry its taken a while to reply. I tried the tape, but without taking the plate off, as I didn't have the tools. As it didn't work I ordered a new magnetic plate, which was delayed arriving! Finally today, with the correct tools, and more you tube videos, we removed the pedal. The centre plastic grips were intact. But we replaced with the new one. After putting it all back together, the sensor was not working. I noticed the new plate was smaller. As I was near to tears, we decided to try the tape method again, with the old plate. But this time with the tape around the axle...guess what, it worked!!! I am soo grateful and happy. I am guessing it may have to be repeated in the future, but for now I couldn't be happier!! Thank you again

 

[Nealh]

Jolly good at least for now one has a working bike again, the tape method is certainly easier to accomplish by pushing the disc on to the tape once it is wound around the Bottom bracket axle.
One can also try using amalgam tape instead of electrical tape.
Though the spline are intact they do lose grip, if it slips again either replace with a correct size one ( with a pic we can link to one to buy) or try soaking the disc in very hot water and gently open the spline up and cool the disc to try and reset them .