Originally Posted by palesaint

Just as important as practicing filling with co2 at home instead of on the side of the road for the first time, it's also good to get familiar with how a tire feels at different pressures. Start at 40psi and spend some time looking at how the tire sits and feels. Then pump to 50psi and observe again. Keep adding 10psi until you hit max psi on the tire or the pump gives out. Repeat a few times. This way you can give bursts of co2 and feel the tire until it's where you want it. If you are ride at 100psi, you should be able to feel the tire and get with 10% accuracy.