Thanks - you're right, it is a Schwalbe. I only just replaced the original Dunlop and its tube, although the clearance can't have been *hugely* better on that. Is there a good way to replace the bolt with a shorter one, instead of trimming it? It's in the original rubbery reflector housing, and it looked like the bolt was underneath a flat metal plate underneath the red plastic disc and the foil backing and I wasn't sure how to take the housing apart further without damaging it.