Fork seals

[ukzknos]

I'm getting quite a lot of fork travel as revealed by oil witness lines on the fork stansions following a ride.
I guess I need to replace the fork seals; is this a [size=14]BIG[/size] job or straight forward?

[Bob_Roller]

No , it's not a real big job, the only real 'hard' part, is depressing a cap at the top of the inner fork tube, and extracting a wire circlip, so you can remove the springs.

Check to see if you have an allen wrench to fit the bolt at the bottom of the fork, that holds the damper in place, other than that, a 13 mm socket on a long extension 24 inches long (55ish cm.).

You do need to remove the forks from the bike, so the brake calipers, and front wheel need to be removed as well.

[Justin B.]

I'm a bit fuzzy here.  I've never heard of fork seals "causing" increased fork travel and if you want to change them you do NOT have to remove the forks, just the sliders...

[montmil]

Prior to pulling the lowers, have you considered draining the fork oil and refilling with the correct weight and volume?

Go for a ride and see if there's any difference in performance.

Monte

[Yikes]

It really is not a big or expensive job, especially if you just pull the sliders from the botton and don't pull the forks from the triple T's.   The thing tha takes the most time is the cleaning of the sliders and fender and calipers and wheel, if your seals have been weeping oil.  If not, take Monte's advice and just drain and replace the oil to start with.  That's real EZ. [smiley=wink.gif]

[montmil]

Other than re-sculpting the seat you can put just a tad shorter rear shock on the rear and then slide the fork tubes a corresponding amount up...

Yo, Justin... scroll on down to the "Lower Seat?" topic. We be fork seals here.   Monte

[ukzknos]

Thanks Guys, I'll try changing the oil first as advised.

To clarify Justin's query my assumption of long fork travel is related to losing oil from the leaking seals?

[Justin B.]

The fluid is for damping...

[ukzknos]

low fluid, no damping & therefore long travel?

I bow to Justin's superior knowledge but it sounds about right to me?


Steve

[Justin B.]

Well, I have no superior knowledge but with shock absorbers when the juice leaks out the travel is the same but there is no dampening.   I suppose it could give the appearance of traveling farther since there would be little or no resistance to travel...

Is there fork oil all over everything?  +2 on Monte's advice on doing a fluid change and see what happens.  Bad seals will be very apparent as fork oil will make a mess out of the front of your bike!  BTDT...

[ukzknos]

Will do an oil change tomorrow, thanks for all advice!  

[Bob_Roller]

Before you do  anything else, pull the rubber caps off of the lower tube, and see what you have there, if there is a fair amount of oil in there, it may be in your best interests, to go ahead and replace them now.

If all you have is a little seepage, clean it up, drain the oil, and replace it with fresh oil, standard weight oil for the R65, is 7.5 weight, if you can't find this weight oil, go to a 10 weight.

I think for a standard oil replacement, 190 ml is the recommended volume of oil for each fork leg.

It hasn't been mentioned yet, but the small drain plugs on the back side of the fork tubes, are very easy to strip out !!!!!

Also if you remove the drain plug, and nothing comes out, use a small diameter wire, or such, to break up the plug of dirt, that is clogging the hole, compressed air can be used from the top, but it makes a large mess, I only did it once !!!!

[montmil]

If it's been some time since your fork lowers have been cleaned out, and that would have had to be done by a PO, here's what I found in mine.



The pile of black junk was a silty, oily, sludge. Always wonder how so much got by the seals...

Monte

[ukzknos]

This is a great site, you regular contributors and administrators are gems.......... but have you no real work to do!  

[Bob_Roller]

I 'play' for a living on Boeing 737's, so I really don't have a 'job'.

I go to work, and play with airplanes, and when I get home, I play with motorcycles.