one other thing w/ the small portable pump, if you're using it on Presta valves (most likely), be *very* careful getting it on and off and while you're pumping. Since there's no flexible tube between the pump and the head, it's really, easy to snap the valve with torque if you're not careful. I did this to three tubes before swearing off portable pumps entirely and carrying a CO2 cartridge on rides instead. So.... yeah... be careful