An upgrade from the one-piece B-2 Air Flow brake shoes B-1s are a great way to add versatility and vibrant color to any bike equipped with linear-pull brakes. The B-1s have cartridge pad holders to fit 70-millimeter replacement pads making it easy to swap out worn pads or for the style conscious to change pad colors. Just pull out the pin slide out the old pad and replace it with a Promax B-1 pad pad insert in one of several available colors.