Originally Posted by DannoXYZ
Stuff that into the 0.015 liter volume of of a cartridge and you can figure out how much pressure's in there..
That's true. Bt to figure out the final pumping pressure, you'd need to figure out what pressure 12g of CO2 would be when it takes up the
combined volume of the tube and cartridge. It will be lower than the pressure that's intially in the cartridge, since the cratride will lose significant pressure as it fills up the tube. When the tire stops filling they're at a new equilibruim pressure.
My guess is that the cartridge is initially at WAY higher than 90 psi. It it started at 90, you'd probably only be able to get the tube to fill to about 30 psi as the cartridge is emptied. If you want your equilibrium pressure to be around 90, you'll have to start with a LOT of pressure in the cartridge.