Pedal sensor magnets

betisbikes

Finding my (electric) wheels
Jul 27, 2021
8
2
I appologise if this has been asked before, or if I am posting in the wrong place, but my question is, why are there 5, 8, 10, and 12 magnet discs for pedal assist. Is there any advantage having more, and do some controllers only work if they have the right amount of magnets, and how would you know, or is it trial and error if you were trying to fit a Chinese controller, without an instruction manual, to replace a faulty one on an old bike where it is impossible to find a direct replacement. I understand that with a lot of the LCD displays, the number of magnets can be set.

Thanks.Ian
 

sjpt

Esteemed Pedelecer
Jun 8, 2018
3,814
2,745
Winchester
In theory there is an advantage to more as it can reliably detect pedal turning more quickly.

Many controllers are adjustable either via the LCD or via a computer cable. Someone (Nealh) can give much more precise details, probably including the setting you need.
 
  • Like
Reactions: betisbikes

betisbikes

Finding my (electric) wheels
Jul 27, 2021
8
2
In theory there is an advantage to more as it can reliably detect pedal turning more quickly.

Many controllers are adjustable either via the LCD or via a computer cable. Someone (Nealh) can give much more precise details, probably including the setting you need.
Thanks
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,882
8,517
61
West Sx RH
12 magnets are often most problematic so stick with 8 or 10, I find 10 the best.
The more magnets the less part rotation the cranks need for power to engage and better low speed control.
Real cheap bikes and systems will use 5 but to be honest why bother when the qo works so well.
If replacing a controller then opt for a KT and lcd, they are dearer then most but are the most widely sold non oem system.