magnet

I had a rear wheel rim replaced on my Bosch system ebike. The technician forgot to put the magnet back on the wheel. It will be several days before I can get the magnet. Will it cause any problems (other than unrecorded mileage) if I ride without the magnet? Details that I assume are irrelevant...

I had a slow leak and finally got around to changing my rear tube. I knew it was going to be a pain. After I replaced it, the control unit doesn't register speed. I talked to a dealer service center, and they said it can be that the magnet on the rear wheel is misaligned. Anyone have any...