[MENTION=345721]blastro[/MENTION], what is the saddle? I do virtually all my riding in chinos. That's 5000 - 6000 miles each year. I wear chinos for my commute (12 miles daily) and for recreational rides (I ride a century every month, and usually a metric century as well). All in chinos; padded bike shorts &c just don't work for me. Of course my pants do wear out eventually, but by that time they usually grease stains and worn out pockets as well. Clothes don't last forever.

My guess is that your problem is there's too much friction between the saddle and the pants; hence my question about your saddle. I'd recommend a hard leather saddle (i.e. Brooks type) with a smooth surface and the rivets beaten down so they don't protrude.