Blackburn TRX 2 Ultimate Commuter Rear Rack. True to its name, the Blackburn TRX 2 Ultimate Commuter Rear Rack is the perfect platform to carry gear to work or run errands around town. This rear rack is constructed of aircraft quality 6061 aluminum for outstanding strength and durability. It features both high and low pannier mounts, an integrated fender mount, plus a mount for a rear light or reflector. It's supremely versatile in that it will mount to bikes with wheel sizes from 26 through 29 which means virtually any adult road, mountain, or hybrid bike with rear rack braze ons will work just fine.