Bike #1's saddle bag could fit a kitchen sink into if I tried hard enough. That holds money, snacks, CO2 inflator, cartridges, tubes, levers, a mini-tool, cell phone, keys, and room to add all my clothing that i'm ready to remove after it warms up. Bike #2's saddle bag is small. It holds money, mini-tool, CO2 inflator and cartridge, tube, levers. The essentials. It is water proof, unfortunitly, I don't have enough room to put my cell phone in there if I was to get wet, unless I rearrange and put stuff in my jersey pocket and everything else goes in my jersey pockets also.