Stiction in fork legs?

[Arbreacames]

I have been noticing for a while that my R tends to "hop" a bit on relatively smooth roads. I think that it is because the fork legs extend with too much (sticky) friction. Where can this stiction be coming from? Fork damper piston? Fork seals? Fork braces? Shock absorber?
Thanks!

Carlos

[BigC]

What year R? There are adjustments for the shocks as well as the spring pre-load described in the "Riders Manual" for my '04. Refer to section 2-41, 2-42. I think mine are set too stiff after zero'ing things out a year or two ago. Probably just getting old and not feeling the "sporty" ride....

[Arbreacames]

The shocks can be adjusted, but that's not the problem. I worked some WD-40 into the for seals and the suspension is MUCH better. For some reasons the seals have too much friction. I had never seen that before.

[towerworker]

Carlos those fork tube seals get dry and will get brittle and crack eventually (ones on top). I rub some silicone grease into mine as well as some other rubber parts on the bike to help them last longer.

[CycleRob]

Carlos,
You have a problem I never had to deal with when I owned my OilHead. You can individually test each tube's stiction and use it as the "before" for what you'll definitely want to do next. With the bike on the centerstand, unbolt just one top fork tube at a time, unscrew the top air vent relief screw and move it up-n-down by hand. You have to remove the air vent screw so it'll subtract the air compression force when the tube is pushed down. How each tube reacts will tell you they are good or bad and which one. If they are bad, your WD-40 solution is only a temporary one, as it evaporates. Try grease! Here's the why and how.
Those fork seals are really far away from the oil level, unlike conventional telescopic forks, and over time and a lack of BIG BUMPS they can dry out and drag heavy. That quickly accelerates their demise. My recommendation is to take them off and take them apart. Fortunately, unlike conventional telescopic forks, the TeleLever fork seals and fork bushings are NOT traumatized or damaged at all when the fork tubes are removed for servicing. They appear to be designed that way. Then you can flush out and change the oil, partially Moly grease pack the main seal wiper cavity (air space between the seal "rings") and put them back together. That's the "mechanic's own bike" inexpensive solution to extend their lifespan and make them functionally Good-As-New (hint, hint). With the age of your bike's fork seals, considering how easy it is for you to change the fork seals if/when they leak and how much longer you'll keep it, (rather expensive) new seals would be best. Then the suspension stiction and service life will be Good-As-New!

BTW, analyzing this problem in depth has me longing for all the advantages of that amazing TeleLever front suspension and it's user friendly servicing design. They may have intended those advantages for the BMW techs and service time, but it works great for wrenching owners. What I have just described would be a great winter time service for caring, capable Boxer riders whose bike is older than 7 years or so, when the fork oil is "used".

[Arbreacames]

Thanks, CycleRob! Good advice, as always. In my mind, I was considering disassembling the fork from the wheel up but your idea of disassembling the tube legs from the top brace will make things much easier. I will start collecting info and parts for this small wintertime project.

[Boxer]

And Carlos! Since Towerworker has failed to remind you...Don't forget during the winter time maintenance regimen, that you need to change out the anti freeze in the two radiators.

[towerworker]

I'm glad that at least some of you guys are finally learning!

[Arbreacames]

I can't believe it, but even BMW is listening to you, Towerworker:

[CycleRob]

Carlos, If you will be just taking off the top fork tube attachment bolts there is more you and others may need to know to make the job safer, easier and damage free. I advise you to take them off the bike and put them in a vise between two 2x4 wood blocks just tight enough to prevent movement. The Aluminum fork sliders (that mount the calipers) have a bottom oil drain plug (part 9 in diagram below, 10 is an O-Ring), but you need to remove the front wheel axle to get at them. I recommend you add some weight to the attached system cases to make absolutely sure the bike does not tilt forward onto the near vertical fork tubes when you "do things". Then you'll be able to flush out the old oil, years of bottom sediment, put in new seals if you want to and new synthetic fork oil.

If you'll be replacing the seals only parts 4 & 7 in diagram below are needed. Be very careful the big screwdriver or prybar you use to lever out the old seals does NOT go too far and scratch or gouge the ID of the tube sliders (where the oil seal contacts). Also, use a steel putty knife as a prying fulcrum to disperse the prying load and prevent a dent-gouge in the soft Aluminum top surface. For a much easier seal removal, heat up the Aluminum in the seal area with a heatgun. The new seals get Moly grease on the ID and a thin vapor film of grease on only the lower seal's OD to ease installation and improve the oil sealing. The top dust seal, part 7, goes in dry, pushed in with 8 strong fingers.



I wish I was there to help you, it's almost a fun job compared to working on conventional forks.

[billbeemer]

nice write-up. my '03 r1150r has a related problem. i have raplaced the right front fork seal 3 times and it still leaks. i feel a small chip in the fork stanchion in the area of compression. how do you repair these? a stanchion is $400 or so bucks, too much for me.

[captaincable]

CycleRob noticed the other day that my forks on My R850 needs to go thru this process as well and found a couple of rough spots on the tubes which he said after taking apart to use a block of wood and around 1000 grit or finer sandpaper to hit he high spots so as not to damage new seals .
I was looking at the parts list and assume those parts come in pairs when ordered, will order this weekend. My forks have a lot of road rash any suggestions for making them look better aside from powder coating?
Mike

[BigC]

Looks like CycleRob has the solution again and has now given me a purpose over the winter months, lol. I swear I looked at those fork tubes and saw no drain plug and thought, No maintenance! Damnit

[Arbreacames]

Clear and helpful as usual. Thanks Rob!

[eduardobelmonte]

CycleRob...,

I'm planning to install Fork Gaiters on my R1150R.
I just replaced oil seals and dust seals and fork oil on them.
Also polished the forks using aluminum foil and Brasso.
They are nice...

The seals I took away were rotten and OLD.
Don't know why, but they were not leaking.
The amount of oil I found inside them was less than the correct amount but not by a big amount.

No, if you please, my question would be.
Would you suggest to use some grease, or silicone spray over the forks
on the part to be covered by the gaiters?
Now and then I could repeat the process in order to make the seals last longer.

I'm not complete sure silicone is safe for the seals.
Grease could be too heavy and perhaps could attract the dust that could get into the gaiters.

I do want to use the gaiters to prevent oxidation of the works, which has already started.
The covering I'm suggesting here about (grease, silicone) would also help preventing oxidation.

Well, thank you for you help.
Best regards.

Eduardo.