Thanks I've seen Heine's tire pressure math but his tables only go up to 175lbs in the extended version, and I think you're supposed to include the bike weight in that figure

using the formula on this page: http://www.biketinker.com/2010/bike-...-for-bicycles/, the apparent tire pressure for a 195lbs person on 42mm tires should be 75psi (if I don't include the weight of the bike) or 87psi if I add 30lbs for the weight of the bike.

Maybe Heine should put a disclaimer that he doesn't recommend these tires for people over 180 lbs

edit: oops.. i never looked at the tables carefully enough before, but it seems you're supposed to calculate the psi per wheel based on weight distribution, so the recommended PSI is 40 assuming 50/50 weight distribution of 195 lbs rider + 30 lbs bike. Seems like that is verging into pinch flat territory on a skinny tire, but i'll check the psi next time i go out for a ride