I'm having the hardest time pumping up my tires on my road bike today. I have never honestly done it myself. I went to the bike shop today to buy a Joe Blow Sport floor pump and have been reading online tutorials, but just can't seem to figure it out. I know I have a Presta Valve and I can get it to release a little air by tapping that valve, but I can't seem to get the pump attached properly. The gauge on the pump still reads 0 PSI, even when attached to the bike. I can get it up to 10-20 PSI, but not for long. Any suggestions?Thanks!