I was un-doing the rear axle bolt with a rather big breaker bar, and I'd managed to use the wrong adapters (I get confused between my dad's bike and my own - seperate adapters), so one big pull and it was off, with no back wheel. Luckily my mate grabbed it and we quickly put the back wheel on and lowered it to the floor. With the correct adapters in place it doesn't move a mm now.