what is the average amount of pre load supposed to be on the front and rear wheels?? mountain bike. i know that if you leave just enough to barely feel movement in the wheel, then tighten wheel, seems like i'm constantly having to re adjust. if i put any load on it just past the no play area, it feels kinda ruff...but when i squeeze both ends manually like i'm installing it, it gets smooth...is the rufness correct before preload after tightening wheel?
Bearing adjustment is part science and part art. It is based on a sense of feel from trial and error. It should feel smooth when spun, with the least amount of play. If it feels rough it is too tight or dirty. I had the most difficulty with tightening the jam nut after I made the adjustment. It seemed that the cone always got too tight while I was locking everything in place. You may find it easier to have a helper hold a wrench on one side while you hold the other cone and tighten the jam nut.