I'm going to be buying a new crankset and bottom bracket (probably and ISIS setup or Octalink, haven't decided). My BB shell is 68mm and the BB spline is 113mm. I realize I need the same size with respect to the shell, but does the spline have to be 113mm? Will it not being 113mm throw off my chain line? Or does it all depend on the crankset/bb combination? Will one crankset give a different chainline from another, setup on the same bb?