I had a flat on my Monday ride. Fortunately, I carry a spare tube and tools. i also bought a CO2 cartridge tire fill set up last year. This was the 1st time I'av had to use it. Well, it works GREAT! back on the trail (Grant's) in 10 minutes with a properly inflated tire. I know with my old frame pump, i couldn't get the tire that full. that CO2 device was worth every penny.