What is the difference between the Tailfin Racks, and the AeroPack?

The AeroPack is an integrated seat pack, meaning that the top bag and arch are connected together. With the Carbon and Alloy Racks, the top bag is detachable. For some riders this is an important difference, for others, it is not. The AeroPack is lighter for the weight-conscious rider and has a more simplistic design - which is sometimes preferential on longer trips.