From what I've read that riding under-inflated can lead to more flats and bottoming out on rough road conditions. Over-inflating can damage the wheels and the rump, too. On my Cinelli I use Victoria's Open Corsa and on the Colnago C50 I have Veloflex Open Tubulars. The Victoria's ride harsh, the Veloflex ride smoother, both have 8 bars or 115psi inflation, the minimum required inflation. Fortunately, I weigh less then 150 lbs.