I thought you guys in the Husky forum might be interested in this. I did a little 2D geometry layout on the computer to try and help myself understand the dynamics behind Husky’s new CTS concept, where the countershaft sprocket shares the same center of rotation as the swing arm. As many of you know from reading tests, the new 449/511’s are sometimes said to “stand up in the corners” or have the rear end ride high when accelerating through turns. Husky’s own literature claims “less rear wheel squat under acceleration” or something to that effect. I wanted to understand how the CTS causes this to happen. Just looking at the CTS setup, it is not intuitively obvious as to how you would have less “squatting” with the shared axis. I could understand how the chain tension stays constant through the range of rear wheel travel, but not the reduced squatting. If you do a simple 2D layout, however, it is pretty easy to see. The answer can be found by looking at the top run of the chain relative to the swing arm pivot as the swingarm goes through its range of motion. Do that for the CTS (shared axis) versus a conventional (non-shared axis) setup and you can see the difference. With the CTS setup, the distance from the swingarm pivot to the top run of chain is constant regardless of where the swingarm is in its range of travel. This constant distance is simply the radius of the countershaft sprocket, and it is the same at 11 inches of rear wheel travel as it is at zero inches of travel. With a conventional setup, the distance from the swingarm pivot to the top run of chain increases as the swingarm goes through its range of travel. This distance is roughly twice the distance at 11 inches as it is at zero inches of travel! What this means in engineering terms is that under acceleration, i.e. when there is tension in the top run of the chain, there is a significantly smaller torque acting to compress the rear suspension in the CTS setup versus a conventional setup, hence less squatting. Or to put it another way, the further you are into the rear suspension travel during a turn, the more your chain is trying to compress your rear suspension with a conventional setup; the CTS minimizes this effect and therefore rides higher in the rear, all things being equal. So it more a matter of what the CTS doesn’t do that makes it unique when it comes to handling – the chain has less compressive effect on the rear suspension under acceleration due to the fixed chain offset distance.