Consensus on Fork Seals

24 replies to this topic
  • DaveJ

Posted June 07, 2002 - 06:57 AM



Here's my take.

I have over 300 hours of hard abuse on my 00 with the factory seals. No leaks.

Here's what I think are the two biggest causes of premature seal wear.

1. Water spots, the results of minerals in normal tap or well water, can slowly destroy the seals. The spots are often not seen, but can remain on the tube for the life of the bike. Even if you don't wash your bike, we all ride in mud and stream water, which can adhere minerals onto the fork. The forks tubes should be polished regularly and each cleaning should be followed with a light wipe (don't spray) of WD40.

2. Poorly aligned forks. This has got to be one of the most ignored issues when installing the front wheel. The problem is that the forks do not remain parallel after the wheel is installed. This stresses the seal and sliders with each stroke.

The old-school of bouncing up and down on the fork before you tighten the axle is limited since the down force causes the fork casting to bind against the axle, not allowing for 100% accuracy. Therefore a before-wheel-installed measurement should be made against a post-wheel-install. Large calipers are a custom gauge is best.

In addition to this, coatings like titanium-nitride can make a difference as well, but we’ll leave that out for now.



  • John_Lorenz

Posted June 07, 2002 - 07:14 AM



Ya know the Water spot thing is a good idea, In Hollister the water is so hard when a puddle dries you can use it in a sling shot to kill a bird.

Thanks for that tip

The Fork Alignment, I totally agree there also 100%.

I will before buttoning the front end up (aka Oil, Springs) I place the axle in the forks and raise or compress the forks to bottom. I then tighten the tubes into place. May seem archaic but it works...

Thanks again

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • DaveJ

Posted June 07, 2002 - 07:26 AM



If you measure the inside distance between the fork tubes before you install the wheel, and the distance after you install the wheel, the difference will be about 5 to 12mm.

After bouncing, as you say, the difference is 2 to 5mm.

After calibrating the forks, the difference is 0.

Take your pick.


  • freestyle111

Posted June 07, 2002 - 08:45 AM


i dont know about ky jelly.i was going to try it,but couldnt get it.i search everywhere everyone was "out of stock" or "backordered".clerk at store told me kyjelly is in high demand around here.what i cant figure out is why?i live in san fransisco and there isnt that many motorcycles.could they be using it to pack something other than fork seals?

  • freestyle111

Posted June 07, 2002 - 10:35 AM


this how i test seals and align front wheel at same time Posted Image

Related Content


100 hrs on 2014 yz450f, shim valves or replace them? by ttr230rider6

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  79 replies

YZ450F 03 Sparks driving me crazy by SirAttard

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 replies

Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  35 replies

Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies

First Hare scramble tips by dhend8

Dirt Bike   General Dirt Bike Forums   General Dirt Bike Discussion
  • Hot  33 replies

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.