The topeak rx beam rack is designed for use with the topeak rx rear rack bag range great for commuting and touring the rx racks will fit all topeak rx trunk bags this rear rack is made from a tough 6061 t6 alloy and will carry up to 15lbs making it ideal for the tough world of mountain biking all topeak beam racks use topeak39s patented quicktrack system making it so easy to slide your topeak bag on and off your bike rack it also uses a quick release clamp so if you decide to go out wi