Blackburn central seatpost rear rack this rack is versatile and simple and the rack deck can adjust fore and aft but also flip over to better fit different sized bikes this means whether you have a road bike tourer or mountain bike this rack should work without a problem no frame mounts required performs great with trunk bags light and reflector mounting loop fits seat posts from 22 to 32mm in diameter aircraft grade 6061 aluminium tubing 10kg carrying capacity