Brompton front carrier frame onlyBrompton front carrier frame only Brompton front carrier frame only is our front frame rack for your Brompton bike that allows you to attach any backpack with an "add a bag sleeve." An "add a bag sleeve" usually serves to slide over another suite case trolley. It is "THE" solution for attaching a backpack, without a frame inside, to your Brompton. The frame locks on the original Brompton front carrier block. (not included) but you can get it here from