Re: What tire pressure do you run on your road bikes?///////
I pump my 700 x 23c tyres up to 110psi at the back and 100 at the front. I do them about once every 7-10 days and they have usually dropped to about 80psi by then. Running them at 80psi is noticeably softer, but they regularly clunk the rims on the appalling roads around here. On my other commuter I recently swapped to 25c tyres. The extra 2mm doesn't sound much but they protect the rims a lot better and I run them at 100psi at the back and 90psi front. The speed/effort difference wasn't even noticeable but the ride is significantly more comfortable and the rims don't hit at all even if I run over a pothole by mistake.
On my old 27 x 1-1/4" I ran 90 at the back and 80 at the front on what is basically a 32mm wide tyre. Again, I don't think I noticed any significant difference in speed or effort on commuting, but I do know I miss (and yearn for) the silky smooth silent ride they gave.