Originally Posted by str8shooter
Can anyone tell me what size CO2 cartridges to use with a 700x25c tires. 12gr or 16gr. The recomended tire pressure is 120lbs. I know under inflated tires are bad to ride on. How much over inflated can you be without causing damage. I know I should invest in a gauge but when your on the road its just one more thing to pack.
str8shooter
I use the 16g cartridges on my 23c and 25c tires. By gauge when I get home, they're at about 90-110 psi. As for the overinflation, a loose rule of thumb (it's years old, so it might be dated, but it works for me) is that the pressure listed on the sidewall is about 2/3 of the actual blowout pressure. I'm not sure that overinflation can cause damage, at least until you hit that critical pressure that causes the casing to burst. I routinely run my Michelin Carbon's up at 140-145 pounds (on the rear tire, anyway), and I've had no problems. Before you ask, I do like my ride kinda rough and fast. :-)
Grab some 16's from Wal-Mart, and away you go.