I bought one of these for a bike build I did with the Nashbar “X” Aluminum Cyclocross Frame. I put 160mm Avid BB7 road discs on the bike.

The rack doesn't work at all with this frame. It BARELY clears the disc mechanism, and if you put panniers on there, it wouldn't do that. Also, the arms that are supposed to attach near the seatpost aren't anywhere near long enough for this frame. If I mounted the rack to the point where the V brakes should mount, it would be pitched forward so that the rack platform is at about 15-20 degrees. I have no idea how this thing was supposed to work on *every* frame.

When I tried to mount it, it also was mounting off center on the rear wheel badly enough that I was worried about balance.

It's been cut to $19.95 at REI, and I think this is why. I'd say away from this one unless you're sure you can return it.