something else about MP's . They are very stiff especially in the sidewall erea and after some experimenting I generally ride (road bike 700C) with pressures around 30 PSI, definately never more than 40 and nowhere near the 100+ that some seem to think is mandatory for a road bike! This soaks up the bumps incredibly well with no noticable adverse effects. The obvious danger is a pinch flat but even at 30 PSI they roll over pot holes and the like without any sign of give.. In fact at 20 psi even a "Thunb Test" gives no indecation of pressure!