Bikes come in all shapes and size, and sometimes you may find that there isn't quite enough space to fit the PAS sensor between the frame and magnet disc.
The first check to make here is to see if you can mount the sensor on a different part of the frame - sometimes there's an almost made-to-measure, flat surface towards the bottom of the bike where the sensor will fit right on with no hassle.
However, if there's no such surface or it's still a tight fit, the best solution is to simply remove the hinge mechanism attached to the sensor, snipping off the plastic tabs, and secure it to your bike frame as shown in the picture below:
