Timbuk2 Seat Pack XT - $24.95

Nothing beats the convenience of an under-seat pack. Not that they're very large: the Timbuk2 Medium Seat Pack XT is 6.7x3.9x3 inches, but once you have your important items stashed in the seat pack, they're there when you need them. Stash a spare tube, a patch kit, a multi-tool, and some extra chain in case of the typical mechanical failures.The Timbuk2 Seat Pack XT comes in two sizes: Small (5.5x2.6x2in.) and Medium (6.7x3.9x3in.). It's available in Black, White, Gunmetal, Bixi Red/black, and Emerald/reso yellow/red. - $24.95