I use one on the front, however not on the rear, and it is amazing! It has so much bite and power so my guess would be that this wouldn't be any different on the rear. The only problem i have with them is that they over heat way to easily, so i find myself trying to slow myself down with my feet when going down hills, which can get rather annoying . But, if you want any advice i think Peter Haydon a.k.a. 'Haydon_Peter' either is using, or used, dual BB7s; so, PM him and see what he has to say about them ! Cheers, Joe.