See the issue with this new spindle, the power spline, is that even if you tighten the bolt as tight as you can get it, the crank may not bottom on the splines. Up to this point when you put a bike together, you check that the cranks are tight and you are done with the cranks. On the Powerspline you have to check that the splines are bottomed out and if they are not, pull the cranks and reinstall them until they do seat out. That was not in the manual that came with the bike and only brought up in an SB after we brought the problem up with Sram.