20mm Conti's keep blowing off the rim!

Sounds like your rims might be too wide. If you really want to ride high pressure, look into tubulars. Nicer ride, and 150psi is no problem.

If you don't want to change rims, Tufo makes some tubulars that fit clincher rims. I have no personal experience with them, so I can't say if they're any good, but they are on the market.

TiMan said:

What the heck.....is the pressure rating too high for these tires or is the problem in my Bontrager rims?

Most likely your rims and tires are on the opposite ends of the tolerance for the 622mm bead diameter. I wouldn't switch either the tires or the wheels though. There are a bunch of other threads here if you want the details, but unless you're on a track inflating over 115-120psi is going to make you slower.

artmichalek said:

There are a bunch of other threads here if you want the details, but unless you're on a track inflating over 115-120psi is going to make you slower.

What he said. Inflating to much over 110-120 is not going to return any benefit in speed/rolling resistance, will make your ride harsher, and obviously increase the risk of the tire blowing off.

artmichalek said:

There are a bunch of other threads here if you want the details, but unless you're on a track inflating over 115-120psi is going to make you slower.

What he said. Inflating to much over 110-120 is not going to return any benefit in speed/rolling resistance, will make your ride harsher, and obviously increase the risk of the tire blowing off (pretty scarey in it's own right -- have you been injured?).