Ive got a summit shaft which is +3mm longer to cure the alignment issue. A set of 441 ramps with spring pins. A 160/350 primary spring pl/pk and a Black secondary spring 160/303. To cure the slipping issue. All brand new 400$ plus shipping. Did this to my 16 freeride 137 2.25. Night and day difference. This set up comes stock on the 146 and longer freerides/summits. If you ride off trail with a 137 you need to compensate for track load. I recomend going to at least a 21/45 as well. Im at that going to 21/49 this week. The shaft is $409, the ramps $90, the springs $60, ramp spring pins $4. Plus tax.