Heavy Duty, LR Torsion Arm, Straight, 600cc, 7/8" x 13" for X4, X6, & X7

Heavy duty 3/4" thick version of the standard version of the 40-175 torsion arm.

Depending on if your left rear rack is offset or not (we have changed this several times over the years) and which engine platform you use, you may or may not need the 40-176 offset left rear arm to get the optimal left rear bearing carrier position.

It is best to get the left rear bearing carrier out closer to the sprocket to allow the use of shorter chain guide block spacers (½" to ¾") is best. This will apply less force on the bearing carriers bearing from chain force also it will keep the chain block from flexing out of alignment. It will also increase the effective spring and shock rate for the left rear tire (this is much better).


Redesigned in 2017. The X4, X6, & X7 Hyper rear torsion arms are now designed with two shock mounting holes. The idea for the new hole, which is closer to the shackle mounting hole, was conceived when the R&D was being perfo