Technical question here, perhaps my brain is missing something; I'm looking over the manual for the x-rf5 and I can't see why there's a need for a spring between the two sun pinions. I'm wondering if it might be the cause of some of the inefficiency I experience with the hub. Surely a spring between the two pinions should have washers either side to reduce drag. . . but why is it there at all? I'll have to open up a hub sometime to get a clear look at this.