My uni ( a DM ringmaster ) has a BMX tyre on it. That is a 20"x2.5" tyre which I
guess is pretty fat. I have tried a 24"x1.25@ (i think that was the width) but
found it uncomfortable. The only advantage seemed to be that you could go
faster. I think the BMX tyre is possibly more rugged, and it seems to have an
excellent grip. I also found idling easier on the 20" tyre, but that may have
been because I am used to it. Given a choice I would go for the 20"x2.5".
Turning is harder at first, but once the tyre gets a bit of wear (bit like a
slick) it is great.
Phil Mason Optoelectronics Group University of Bath Bath Avon BA2 7AY