From Psimet's Tip of the Day thread...

Tip 1 - Inflate your tires before every single ride. Know what the proper inflation pressure should be for your tires. Inflation requirements will vary by rider, bike, tires, conditions, etc.

Below you will find equations that you can use to help determine an appropriate starting point using your weight and the tire's size. Adjust from these baselines to suit needs and conditions.

Proper inflation is the easiet way to avoid flats.

Tire Width=20: Pressure(psi) = (0.33 * Rider Weight in lbs) + 63.33
Tire Width=23: Pressure(psi) = (0.33 * Rider Weight in lbs) + 53.33
Tire Width=25: Pressure(psi) = (0.33 * Rider Weight in lbs) + 43.33
Tire Width=28: Pressure(psi) = (0.33 * Rider Weight in lbs) + 33.33

Tire Width=32: Pressure(psi) = (0.17 * Rider Weight in lbs) + 41.67
Tire Width=37: Pressure(psi) = (0.17 * Rider Weight in lbs) + 26.67


Example: You are 150lbs running 28's

Pressure (psi) = (0.33*150) +33.33 = 82.83psi (rear)
Front Pressure = .9*Rear Pressure = .9*82.83psi = 74.55psi front\


So for 23s run 112psi in the back and 101psi in the front.