It's a 2.30 on the rear. Clearance is good, it could be a bit more generous around the chainstays but it's adequate as it is. I've had no problems so far with mud build up but I would hesitate putting anything much wider on it.
thanks for the reply. We've got some chunky trails and I like to keep bigger tires on my bikes. just feels better to me. certainly a well appointed frame. Spank Spoon stem? Got any close-ups of the paint? looks like they keep the heat marks under the green. Love the geo-numbers on this frame.
I'll put some up when I get chance. It's a lacquer effect clear finish so you can see all the heat marking underneath, they do a raw version which usually would have been my first choice but this is the best of both as it's still raw-ish if you see what I mean!