Mounting the PAS sensor

[Charliefox]

Now I have come to actually fit this I am wondering if the metal ring is supposed to be glued to the bottom bracket, with the red lump sticking outward. Then the rotor pushed on the axle. Perhaps Chinese bikes are still using locking rings. My BB is a cartridge. I am planning to put it on the LH side. The roto has directional arrow on it.Other designs seem to has the sensor on an arm.

 

[Deleted member 4366]

It's supposed to go on the drive side of the BB, where there's a flange to retain it. You can put it on the left side, but you have to find a way of fixing it. I normally unscrew the BB a couple of turns and to expose some thread, then use a lock-ring. You have to mount the magnet disc the other way up so that the arrow points in the wrong direction if you do that.

 

[Charliefox]

It's supposed to go on the drive side of the BB, where there's a flange to retain it. You can put it on the left side, but you have to find a way of fixing it. I normally unscrew the BB a couple of turns and to expose some thread, then use a lock-ring. You have to mount the magnet disc the other way up so that the arrow points in the wrong direction if you do that.

I got that.Took the crankset off today and took out the BB. Pretty tight fit if the orange sensor is fitted facing away from the rotor..the gap is c.5.37mm. See pic.I could bend the sensor ring towards the rotor though. The other (proper?) way round and the rotor and sensor rub together.One other thing.The magnets in the rotor stick to the steel inner chain ring. I find a layer of plastic reduces the attraction but it is still there.Does this matter..is magnetism lost over time in this way.As always I am sure you have the answer! Neither of my other Ebikes ever had a pedalec sensor so I am eager to see what it is like to power away without twisting the throttle.

 

[Deleted member 4366]

You have the sensor upside down. It dhould face the magnet disc. Normally the bracket is joggled so that the sensor face is more or less in line with the bracket. Your one would be good for a hollowtech BB, where you need to reach over the bearing holder.