so is the only way to switch to the one way bearing is to send it back to STM??
As it was explained to me. yes. In theory, the aftermarket clutches with the one way bearings are supposed to function just like the stock clutches and engine break all the way down to almost a stop. But the issue is the aftermarket clutches have a much smaller diameter bearing so when the primary disengages and the belt rests on the one way bearing, it SHOULD provide engine braking like the stock primary clutch. Unfortunately, they don't……and as it was explained to me, it is mostly due to the smaller diameter of the one way bearing (i.e. less surface area = less contact to the belt) and it's inability to grip the belt without it slipping. It also has a little to do with the secondary and the design of the STM helix which doesn't squeeze the belt as tightly as the stock secondary when engine braking. Apparently, this design works fine on the ATV's due to less load/weight applied during the braking. But is not able to do so effectively on a SxS. So by switching to a 2 way bearing, you will still have the same level of engine braking as a one way bearing setup but if/when the RPM's drop low enough and the primary disengages, the belt will now ride on the 2 way bearing and allow you to freewheel (coast) instead of slipping on the one way bearing and potentially burning it up as I did as well as a few others.