First off... make sure you go off of standard american sizing with these!! I am 5' 11" 170lbs, athletic shape... and the medium is what I had to go with to keep things tight. I normally wear a large in castelli. Other than that, these things are glorious...one of the best chamois out there, I ride the sugoi rs frequently as well, and these are right there in quality and for a great price. I would recommend these bibs to anyone, and frequently do.