i was involved in a low side last year on the track, it was a 100mph corner and the bike slid into the tire wall. i hadn't ridden the bike since then. i recently cleaned it up, replaced broken parts (frame slider, bent rearsets and bent rear rim) and at the time i noticed the lower part of my one fork was wet. i didn't think much of it, wiped it off, and went for a ride. the fork and frame all look and feel straight. after my ride i noticed more wet stuff where the silver part of the fork meets the black on the lower part of the fork. the fork doesn't appear to be leaking from the upper part, as it is completely dry throughout the entire travel portion of the fork. can this be repaired easily (i.e. with new gasket) or must the entire fork assembly be replaced?
The fork leg screws into the lower and is sealed by an o-ring. Unfortunately you can't buy the o-ring and riding on it when it is loose (loose enough to leak) typically deforms the tube. You have a slight chance of matching the o-ring and having it seal but ultimately I would just get the lower tube and replace it. It beats taking it aparts 3 or 4 times trying to save it. Brian
My opinion, replace the leg, DO NOT ride the bike until you do. Maybe replace both to be sure. What can happen, like Brian said, is that in a biggish crash the thread on the bottom of the tube can get damaged. It is a very large, very fine thread. The oil is leaking past the o ring, because of some trauma to the thread. Normally they are screwed in damned tight, with lashings of loctite, and a locking grubscrew. To get them apart you usually need a press, some collars to hold the tube and a big heat gun. Did I say they were tight? So, if its leaking it MUST be damaged on the threaded area in some way, so much safer to replace it. You don't want this happening. http://www.sdracing.com.au/RaceReports/2007-04.htm
thanks for the tips guys. i didn't realize that a little oil leak in that area had the potential to be so bad. the pics in the link clearly show it! fwiw, everything in the front end looks straight and normal, aside from the leak, not even a scratch on the front wheel, rotors or forks, so i'm not sure what kind of impact could've caused this damage. the impact did tear off a woodcraft frame slider puck though.
wow or it could of just compressed the fork hard enough to crack the seal... blown fork seals are usually a thing from a wheelie being set down to hard... but they do happen for other reasons... while i agree in a crash with impact it could of bent the inner tube... it might not be... while they are apart to replace the seals which you need to do both side when you do it... the leg can be checked to see if it's straight...
