Cadex AR 35 12-Speed SRAM XDR Freehub Body

The New Giant Cadex AR 35 Freehub Body SRAM XDR 12 Speed New innovations.

The 35 AR disc use a ratchet-type hub with limited parts. The freehub comes free with a yank once the cassette is off. Inside is a spring holding an outer ratchet hub against an inner ratchet that stays stationary against the hub shell. Looking to add "quicker timing, quicker engagement, lower friction and better efficiency" the new design changes both the spring and the number of teeth.

Responsible for holding the outer ratchet against the inner is a small spring. While the old road hub design, as well as the similar DT Swiss design, uses a round coiled spring the 35 AR disc changes the spring to a flat design. Moving to this design means that the natural plane of movement is entirely vertical as opposed to both vertical and horizontal - think of the way a slinky moves. There's no wasted energy as the spring pushes against the shell of the hub and less chance of distortion if you change freehubs.

The ratchets have also undergone a design change. The older hub uses a 36-tooth ratchet engagement. The R2-C60 hub moves to a 60-tooth design. This helps overall efficiency and makes for faster engagement.

In terms of the hub and it's incredible how simple the design is. Open it up and there's a ratchet side that's locked into the hub then a floating piece that interfaces between the freehub and the rest of the hub and a spring that holds it all in place. That spring is ripe for distortion as it locks itself against the body of the freehub and moving to a design that only moves in one plane of motion makes a lot of sense. 

MODEL ID: 300000124