50 is ok for the normall tuffs, I used to run 60 psi in my Graphites with new school tyres 
Yeah i was gonna quote you on the 60 psi thing Billy

I thought feck sake when you told me that at the Brits this year

It's down to the wire in the tyre walls

I put just over 40 psi in some black walled comp3's on my 24" tuffs
and an hour later they blew off and exploded ,,,,,shitt myself as I was sat down next to my bike at he time having an 99 Ice cream

I think I did a Mr Whippy in my pants too
