Great question — answering as the UphillTech team:
The holes develop for three reasons: The pants are being stretched excessively. The seat is rubbing on the pants. The fabric is not sufficiently durable. I ride a bike to work, so know from experience. Cheap, thin, coarse-weave polyester fabric is best. It is cool and doesn't hold water when you get hot and sweat. Not being jeans they are a bit looser and the fabric holds up better than denim. Such are surprisingly inexpensive costing less than jeans if one looks around. They can be bought at places like blair.com. I have several pairs from there lasting several years of daily bike riding. Riding a bike regularly requires a change in clothing style to facilitate comfortable riding. The seat...
Full answer by subjectivist: https://lifehacks.stackexchange.com/a/5537 (CC BY-SA 3.0).
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