Perhaps I need to change my user name so people don't think I'm 5 and I've just bought a Raleigh Grifter !
d45yth - My point is this... having been riding now for many years I've been through quite a few tyres all with different designs for different conditions. IMO all tyres have a point of equilibrium where the tread is working to the best of it's designed ability and often this is with a higher pressure rather than a lower pressure. If the pressure's too low the tread gets swallowed up into the tyre, rolls around and creates drag with very little grip, too high and the tread doesn't get chance to grip the surface. Again IMO, some people often make the mistake of trying to achieve more grip by lowering pressures when in actual fact they are compensating for a poor set up on the bike. The suspension should be set up to take as many hits as possible thereby leaving the wheel in contact with the surface as much as possible and if the tyre is at it's equilibrium point then the tread will give it's maximum grip. On a similar point in my experience when it comes to muddy conditions a fat tyre at low pressure will simply sink as it tries to float where as a thinner tyre at a higher pressure will carve through the mud.
d45yth Now I've had a rant I would welcome your advice on my current problem. I'd been running the UST tyres on the Easton wheels at about 30 to 35 psi but I've suffered 3 flats where the UST tyre has split just above the rim. I suspect Donk made a valid point in that the rims are a lot stronger than the Mavic's on my old bike and the bike is a lot more aggressive, as is my riding. Hence having bought a new Ardent (because I was very pleased with the grip, at a fairly high pressure) I'm going to try running them at 40 psi in an attempt to try and resist the flats I've been getting. A viable solution or am I still beyond help.... 'Help me d45yth, you're my only hope'