How heavy are you? You must be a gorilla if you need 140psi. I'm around 160lbs and run around 100psi on a 700 x 23. Any more and the bike starts skipping around on bumps, especially during cornering.
All tires have a pressure rating on them. I suspect it may even be a legal requirement. Sometimes it is just embossed somewhere on the sidewall.
110 is where it's at, anything lower and riding is sluggish. Just check on it every week or so.
edit: I don't think any clincher can do 140. That's one of the reasons tubulars are used on the track.
the panaracers on my bike show max psi as 150. i think most clincher rims wont take high pressure though (if i remember its something like 120-130 max on most clincher rims). i have yet to pump them up beyond 110.
Originally Posted by benda18
it's a wash when you account for the calories the prius owner uses to pass judgement on people who can see beyond the veil of greenwashed consumerism.