Boxerworks.com

Kurt in S.A. wrote: ↑Tue May 25, 2021 4:30 pm I think he was talking about something like #4 in this diagram:

https://www.realoem.com/bmw/enUS/showpa ... Id=31_0314

That would be a dealer item IIRC.

Kurt in S.A.

I wasn't referring to any type in particular, just commenting that you need something to keep the Shat and Crip away from the oil seals.

Rob

Rob Frankham wrote: ↑Wed May 26, 2021 6:25 am
I wasn't referring to any type in particular, just commenting that you need something to keep the Shat and Crip away from the oil seals.

Rob

Noted. I think I'll be applying new gaiters on them. Make it better for the long-term life of the tubes themselves.

melville wrote: ↑Tue May 25, 2021 11:18 pm You really want gaiters. Bare tubes are subject to stone damage, which in a humid environment quickly becomes rust spots.

I have a /6 and a /7 that lived their lives on the coast, with gaiters. As much as I can tell, they are on their original fork tubes.

I have an RS with just 15K miles (RS have bare tubes), parked since 1985, that will need new fork tubes.

The Rancho gaiters will work--I have gaiterized a non-gaitered Yamaha with them.

Noted! Reading this the first time definitely made me want to go this route. Thank you!

My R90S has 150+K miles on it and the fork tubes are fine. Never had gaiters. The dust covers use a felt ring to oil the forks as the sliders go up and down. The oil prevents rust and keeps the bugs from sticking.

Plus they look better than the gaiters.

Mike

MikeL46 wrote: ↑Sun May 30, 2021 5:02 pm My R90S has 150+K miles on it and the fork tubes are fine. Never had gaiters. The dust covers use a felt ring to oil the forks as the sliders go up and down. The oil prevents rust and keeps the bugs from sticking.

Plus they look better than the gaiters.

Mike

Ha, yeah. Seems to be two sides to this coin. I'm not a fan of the fact of having to damn-near rebuild the forks just to get to the point where I could put new gaiters on without cutting them. I'm not sure how I wanna proceed, though. *sigh*

Whether you go for gaiters or dust covers, you don't need to dismantle the forks to replace them. Simply strip away the fork calipers and front fender (tie the calipers back to the crash bars if you have them or somewhere else to support them. No need to dosconnect them). Remove the wheel, remove the top nutsand lower yoke pinch bolts then simply slide each fork out of the yokes. The only tricky bit is making sure they're aligned when you refit them. If you're careful, you won't even lose the fluid.

The other way to do it, once the brakes, mudguard and wheel are out of the way, is to remove the nut in the bottom of the slider (under the plastic cover). The whole slider will then just slip off the fork tube. You will, of course, lose the damping oil and will have to refill it which means it's probably just as well to time the replacement for a service.

Difficult to know which is easier or quicker but no more than two or three hours either way.

Rob

Great chance to change the oil, add new seals and add the gaiters. Fork oil change is one of those jobs that can be delayed too long I expect.

It's all easy enough, but the only gotcha is that little bolt at the bottom of the forks. One bloke I know had issues 'cause his was buggered, seized, stripped (can't remember exactly, but buggered nonetheless)

The following isn't for the Ate braked forks ie pre 9/1980 but you'll get the idea.


Changing BMW R100's 81-84 fork seals/ springs/ gaiters/ oil.

Nomenclature: I call the chromed tube the fork tube. The fork leg is the lower forged bit that the brake caliper attaches to.
On the centre stand….

1. Put new seals in the freezer for 1 hour beforehand.
2. Loosen, remove, the top fork bolt to allow drainage and refill of fork oil..move h/bars to get to bolt.
2a. If you want to replace the springs, you need to remove the large hex bolt at the fork top, therefore no need for point 2. That bolt is very tight and easy to round off. Make sure your tool fits well.
3. Remove the lower drainage small bolt. Allow oil to drain.
3a. Replace springs, loosely replace top bolt.
4. Disconnect brake calipers from fork legs...hang carefully.
5. Loosen, don't remove, the retaining bolt at the bottom of the fork. Better leverage before the axle comes out.
6. Remove axle/wheel/front guard.
7. Now remove retaining bolt, drop fork leg down, leaving the fork tube on the bike. Remove old gaiters/boots.
8. Clean fork leg internals and the chromed fork tubes too. I use a fine wet and dry with wd40 to lightly clean the chrome..
9. Carefully lever out the old seal from the fork leg. I use a blunted straight screwdriver. Insert the cold new seal, use old seal to push new seal in. Do not scratch the mating surface of the seal.
10. Slide upper gaiter spacer then gaiters onto fork tube.
11. Install fork leg with new seal carefully over the fork tube..
12. etc, etc...both sides
13. Reinstall drain bolt, refill oil, tighten top bolt.
14. wheels etc back on...
15. fiddle with the gaiter spacer, locate it into the breather tube on the inside of the lower triple clamp.
One hour max. Quicker the next time.

Rob Frankham wrote: ↑Mon May 31, 2021 5:00 am Whether you go for gaiters or dust covers, you don't need to dismantle the forks to replace them.

This is good news! Although, the more I think about the process, the more it makes sense to just rebuild the forks. Replacing seals and putting in fresh oil, anyway, makes sense considering what little I know about the history of the bike.

SteveD wrote: ↑Mon May 31, 2021 5:07 am Great chance to change the oil...


Changing BMW R100's 81-84 fork seals/ springs/ gaiters/ oil.

Nomenclature: I call the chromed tube the fork tube. The fork leg is the lower forged bit that the brake caliper attaches to.
On the centre stand….

1. Put new seals in the freezer for 1 hour beforehand.
...

One hour max. Quicker the next time.

Excellent writeup! Thank you for that, I think I'll set a Saturday aside soon and make this happen. Thank you!

Why put the seals in the freezer? I don't understand the logic behind that step.

Any recommendation on where to get a decent fork rebuild kit? anything I should avoid?

kmisterk wrote: ↑Tue Jun 01, 2021 2:44 pm

Rob Frankham wrote: ↑Mon May 31, 2021 5:00 am Whether you go for gaiters or dust covers, you don't need to dismantle the forks to replace them.

This is good news! Although, the more I think about the process, the more it makes sense to just rebuild the forks. Replacing seals and putting in fresh oil, anyway, makes sense considering what little I know about the history of the bike.

Absolutely... just making the point that you can do it without...

SteveD wrote: ↑Mon May 31, 2021 5:07 am Great chance to change the oil...


Changing BMW R100's 81-84 fork seals/ springs/ gaiters/ oil.

Nomenclature: I call the chromed tube the fork tube. The fork leg is the lower forged bit that the brake caliper attaches to.
On the centre stand….

1. Put new seals in the freezer for 1 hour beforehand.
...

One hour max. Quicker the next time.

Excellent writeup! Thank you for that, I think I'll set a Saturday aside soon and make this happen. Thank you!

Why put the seals in the freezer? I don't understand the logic behind that step.

Any recommendation on where to get a decent fork rebuild kit? anything I should avoid?

The only significany difference for ATE equipped bikes is that the bolt in the bottom of the fork slider is now a nut located under a rubber cover in the bottom cap of the fork slider. Avoid, if at all possible, loosening the bottom cap on the slider.

Rob