I got a flat today and only had one 16g canister with me and only got about 20 psi out of it. I've used these for the road and easily got 100psi but I just bought this one for my mountain bike's bag and was told I'd get 40psi out of it at the LBS. Tire size is 26X2.1. Todays temp was about 32deg, so will the cold air affect the CO2's pressure? Thanks.