Originally Posted by
shoota
Good pic, but for whatever reason I still can't wrap my head around why being too wide would cause the crank to not spin freely.
Ya know you got me thinking, I wonder if the seal on the drive side got left on there from when I removed it from my other bike that used a regular english gxp bb... I'm going to text my buddy at the shop these things and see what he says.
Thanks for the help guys, hopefully this gets resolved quickly.
If its the guy at the shop that worked on it, you would be better off texting the family dog.
As to why too wide a spacer spread causes binding, its pretty elementary. When you tighten the left hand crankarm bolt the pitch of the thread draws the crankarm into the BB of course. Primary crank forces are vertical and so BB30 bearings are designed to take much greater vertical forces than lateral thrust loading. Increase the thrust loading on BB30 bearings and the inner race presses the balls into the outer race which bind the bearings. This btw is not binary. It can occur over a spectrum. Even slightly too tight will prematurely fail bearings and increase bearing drag.