[aesmith]

Cheers, that's what I know as a "slide hammer". I was trying to work out how to rig one. However I got fed up with the bike being disabled in this stupid way, so took the Dremel to it this morning. As with so many things it's easier said than done, there's no way for example to hold the Dremel perpendicular as there's something in the way of the body all around. So the cut needs to be at a slight angle. And the start of the cut puts the edge of the disc only a couple of mm away from the anodised footrest assembly. However with the slot cut I was able to wrench the cup side to side and gradually rocking it made it walk off the bobbin.

Now to stop it happening again! If I'm going to reuse those bobbins I need to file them around 1mm smaller, there's no need whatsoever for them to be a snug fit. Much better would be to work out how to source or make alternatives that won't corrode. Some sort of hard plastic would be plenty strong enough.