My brother just replaced his front fork seals, we get everything back on the bike and notice that his seat is lower, so he gets on his bike and rear shock is bottomed out. If you pull up on the rear fender the bike will rebound, but as soon as you sit on the bike again it is bottomed out. What could have caused this? He has replaced his swingarm bearings but not his linkage bearings would this have any effect on that. I played with the bottom screw on the rear shock which I believe is the rebound adjustment which had no effect. Any help would be greatly appreciated.