Boonen: Fourth Paris-Roubaix win makes me one of the greats | Cyclingnews.com
During this Paris Roubaix win Boonen was running his tires at about 65psi, far below what most road riders would use. However, it gave him a huge advantage over the cobblestones. This was an extreme example, Boonen had a support car to provide a wheel change if he flatted, so he made a calculated decision. However, the lesson is clear. If roads are really, really bad, lower pressure is faster up to a point. However, if the OP was so careless to allow tire pressure to get as low as 25 psi, then pumping them up to 80 psi was not a logical way to make things better.