Taking metal from LH crank for PAS?

[DynatechFan]

I have been getting ready to install my new kit - one issue is the PAS module, it fits in to the grooves of the sealed bottom bracket but the crank is 1.5mm too deep on the square axle, so there isn't room enough for the sensor

How much material can you safely remove from the back of a LH crank? Or should I put in a new, longer BB?

 

[Deleted member 4366]

I've removed 3mm before. You can normally thin down the magnet disc a bit too with a Dremmel or something similar, as most discs have thicker features near the middle. You can lose something like 1mm from each side.

 

[DynatechFan]

Thanks, d8veh, this isn't the usual sensor I see with a lot of other kits, its a neat little sealed unit about 3mm deep, so I don't think there is any scope to take material out of the sensor - but it sounds like the crank will cope, its a 1990s Shimano

 

[anotherkiwi]

It is a question that has been going through my mind:

The narrow part of the square taper is of course on the external side of the crank arm?

 

[Deleted member 4366]

Time to get out the angle grinder.