Well lets see... they look like 25's. The ham looks to be about 340 lbs, I am guessing. Bike probably weighs about 22 lbs.  Hmm, according to my pressure calculator the tires should be inflated beyond the maximum PSI supported by tires (usually 120 - 130 psi). Front tire needs to be 153 psi, rear tire needs to be 234. I bet this fat fuck goes through tires like crazy.