Have decided on the smallest of the Vaude bags because I have reinkriegen only the most necessary, no lights or something, but they would also really too tiny. But if I have my bones, and a multitool included and it is still place some money, papers, keys or something accommodate. Installation is really super simple and yet keep the Velcro also super. The Velcro fastener for seatpost comes along well with my suspension seat, it is long enough to fit even the thick spring. Am completely satisfied with it.