Originally Posted by
dddd
The "myth" about limited pressure using straight-walled (un-hooked) rims stems primarily from perhaps just one or two careless manufacturers whose bead-seating diameter tolerances were out of the range used by most other rim makers.
In general, rims that don't say Weinmann on them are typically good for 90psi tires, though unless one is over 200lbs there is little reason to use more than 85psi in a 1-1/4" width 27" tire, and I run 'em at 60-70psi even on training rides.
If you go by the Bicycle Quarterly tire pressure vs width vs weight chart (which is based on an ideal tire drop of 15% I believe), you'll find that the ideal pressure for the average guy on a 1-1/4" (32 mm) tire is about 60 psi front/70 psi rear. It's counterproductive to pump them up higher...they'll just get less comfortable and roll slower.