[woodcote]

Glen - I don't know if Scalextric have changed the plastic they use to make their wheels, but I find the wheels on the newer cars quite safe to twist off. The older wheels could be a bit brittle and would crack, the latest ones seem more 'waxy', if that makes sense. Definitely needs a precise, perfectly perpendicular twist - if not, there's still the risk the axle will crack the hub. Then super-glue the axle into the hub... not much glue is needed and immediately wipe away anything that oozes out.

If you do have a wheel that splits, you can repair it with some 1/4" plastic tube (for example Evergreen #228) to use as a sheath over the cracked hub.