Brompton Bag Frames for Front Carrier blockBrompton Bag Frames for Front Carrier block Brompton Bag Frames for Front Carrier block full range. With these frames, you can attach your own backpack or a backpack with an add on sleeve. The frame locks on the original Brompton front carrier block is not included, but you can get it here from our store. This is a straightforward, hard to find solution for attaching a backpack or any luggage to your Brompton. Brand Name: Bromptonic Compatibility: