After seeing my last post on a cyclometer for the hamster wheel, mum posted me one she got from Kellogs.

 I've tried several different ways to fit it to the wheel but sadly the cage isn't big enough to try any more and the others were unsucessful!

The main issue is however that due to the use of magnets every time the magnet nears the sensor it grinds its way around the metal framed cage; it's really noisy and my nocturnal hamster is noisy enough as it is!

Never mind.