A while ago, I purchased a "mini" bike pump to mount on my road bike in case of flats. I think it's the Topeak Master Blaster DX. The other day I tried using it to put some air in my tires (just to see how it worked). I could not get air into the tires! Now, I consider myself strong and in shape and I couldn't believe this! So...I'm considering getting something else. I have considered a CO2 system, but am not sure. Any recommendations? Something small and mountable would be good and something with a guage would be great, too. Thanks!