There is 1 other thing that can create instability. Check for a cracked weld on the rear sub-frame at the cross brace where the fender bolts to it.

Thanks for the advice. The wheel bearings seem tight, but I don't know the history of the steering head bearings. The rear shocks are after-market Koni's, but, again, I have no idea how old they are; however, they seem to be working properly; I don't feel any slack in the swing-arm bushings, The front tire is new. For starters, I'm going to increase the tire pressure in both the front and the rear, and if that doesn't work, I'll attack the steering-head bearings. Thanks a million for the "check list." It's appreciated.

Thanks, James. Based on your advice, I checked all frame welds and can't find any cracks or breaks; of course, internal cracks could be present, but all feels tight. I'll try the tire pressure increase first.

Really. Follow Scot's advice and do the steering head bearings. If you don't know the history of the bike's service, that bike is 36 years old and even under ideal conditions, the grease in the head bearings is like glue now (assuming it has not been serviced in the past 20 years, which seems likely). You do not want that tank slapper.

Thanks to all for the helpful responses. Adding higher pressure to the tires didn't seem to help, so guess I'll bite the bullet and stat taking it apart to service the steering head bearings. I'll let ya"ll know how it turns out. I can't thank all of you enough!!

Determining the need for steering head service is simple. And usually done at the same time as wheel bearing check because the wheel has to be lofted.

1) With front wheel removed, the forks should have absolutely zero play front-to-rear as you push-pull on the bottom of the fork legs. If you hear or feel any movement then the bearings are too loose.

2) The second requires an acquired touch. The forks should rotate effortlessly L to R, lock to lock. They are, after all, spinning on precision tapered bearings. You should feel zero grit or "hunting". There should be zero resistance to turning, having an absolutely flawlessly smooth motion that one gets from turning a new bearing.

As Scot has said, you'll most likely feel "hunting" (a jumping from notch to notch), as well as a lot of resistance to rotation that stodgy. That's heavily oxidized grease. If the bearings got loose, then you may also feel some grit. In my 2 experiences the forks could be let down far enough to service in place. Lots of brush work, carb cleaner, and compressed air. The replacement grease should be synthetic and highly waterproof. In both my experiences the over-sized bearings only needed new grease, not new bearings.

Final tuning and setup includes pre-loading the bearings to a BMW torque spec. This is step important. About 4-5 hours total in a well-prepared home shop.

• Hey, check out the homemade, self-bleeding brake line system sporting 3 stainless steel flex hoses in that last photo.

Hope this helps.

Thank you Wobbly!! You have just saved me a lot of time and improper language by providing the photos. I have removed the lowers and have started removing the upper fairing, and now realize that won't be necessary. I have done the tests and determined that in fact the bearings do need service, but am very happy to know that I don't have to go any further on removing the onerous upper fairing. I can't thank you enough for the photos. I''ll be done by tomorrow instead of sometime next week(or year) Thank you again.

I'll be done by tomorrow instead of sometime next week (or year).

Oh no you won't !!

It will take you a week just to find the correct grease ! You think I'm kidding, but I'm not ! Those bearings aren't sealed, they are open to water, from rain and washing. So the grease has to be HIGHLY water-proof.... unless you want to do the same job again next year. The job of that grease is water protection. The bearings aren't spinning fast enough to need lubrication in the "standard" sense of the word. So look for one that's water-proof (not "water-resistant"), highly tenacious, and if you can find a synthetic rather than mineral-based, the job will last a lot longer, because synthetics don't oxidize nearly as fast.

You'll end up spending $20 on a small tub or tube, but it will be worth it.

PS. You'll know you used the right stuff when it's still on your hands a week later. 😛

Have you thoroughly cleaned about a quarter of the way around one race and checked for brinelling? If found, the bearings will need to be replaced.

Boat trailer wheel bearing grease is waterproof (fully submersible) and readily available.

Thanks, Arni. I found waterproof Green Greese at Napa, which seems to be what is needed. Thanks for the heads up.
Pete (10665)

Thanks, Wobbly. I have finished the steering head bearings with waterproof Green Grease which I found at Napa for about $6. Seems to be a lot smoother, but am having trouble getting the steering damper to work right; it won't turn off the 0 mark. I've tried positioning the damper rod in different locations, but still no movement. I can't find any info about what I am doing wrong, but should be able to eventually work it out.

While the bike's apart, I decided to renew the fork seals; next, rebuild the calipers as the left one appears to be hanging up slightly. You're right, I won't be finished in a day or two, but at least the bike should be much safer.

Again, thanks for your help.

Pete

Since you're not the original owner, someone may have disassembled the actuating mechanism for the steering damper (I'm assuming that the damper itself is not frozen). I had just that same experience on my recently-acquired 1982 R100; the damper was fine, but the knob could not be turned off the "0" position. Turns out that the mechanism can be assembled two different ways (just as easy each way), but one way freezes the knob and gears in place and the other permits movement to the other damper positions.

Take that mechanism apart (not a big deal, just don't lose the tiny springs and pieces), clean, lubricate, and reassemble. It is not intuitively obvious (at least to me) which way is correct, but if you do it wrong, take it apart and do it the other way. When you have it apart, you'll see what I mean.

I have finished the steering head bearings with waterproof Green Grease which I found at Napa for about $6. Seems to be a lot smoother, but am having trouble getting the steering damper to work right; it won't turn off the 0 mark. I've tried positioning the damper rod in different locations, but still no movement. I can't find any info about what I am doing wrong, but should be able to eventually work it out.

Pete -
The only thing that gets the grease washed out faster than the steering head bearings is the dampener mechanism. Look on the bottom of the triple tree. You'll see a small rectangular cover, which you can remove with 2 or 3 screws. The mechanism contains a spring-loaded detent. You should take that detent apart and pack it with the same water-proof grease you used above. Ummmm, nice !!

While the bike's apart, I decided to renew the fork seals; next, rebuild the calipers as the left one appears to be hanging up slightly. You're right, I won't be finished in a day or two, but at least the bike should be much safer.

If you are doing the calipers, then you should seriously consider "stainless steel" brake hoses at the same time. READ HERE.

Hope this helps.

Again, thanks a million. Took the stabilizer apart, cleaned it up and used the magic grease, and now it works better than it ever has.

I appreciate the info regarding bake problems. Very informative and just plain good info. I plan on ordering stainless brake hoses tomorrow. Fortunately, I have a new rear set that I had made for another R100 years ago so plan on changing that one also.

Feels good to be back in the garage again, even better having so much skill available when I get hung up. Hope to be back on the road in a few days. Ya'll are appreciated!

Pete