'82 R65 fork "clunk" Heeeeelp me!

[bjamesw]

Hello,

I bought my '82 R65 in 1991. The previous owner had progressive springs installed and steering head bearings replaced in the quixotic hope to end high speed wobbles. Wobble is still there, but can live with it, but I wonder if his monkeying may have introduced something else that has driven me to near madness through more than a decade of riding now.

When travelling anywhere from five to about forty mph, and hitting railroad tracks, small potholes, or similar, a "clunk" can be heard and felt from the area of the steering column-upper forks. It ranges from a light click to a hard clunk depending on the pothole. At a clunk it could be imagined as a five lb. chunk of metal suspended above the frame by a spring. When I hit a bump, "clunk" goes the hunk of metal onto the frame. I have fully disassembled the bike searching for the cause from the spark plugs foreward. Rebuilt the forks twice, adjusted the head bearings to extremes, done everything imaginable - to no avail. No less than three bmw certified mechanics have ridden the bike, identified the noise exactly as I describe it, and been unable to locate it.

Can anyone HELP me? It would seem a small thing since I've long ago determined that it poses no hazard to me. But I think any rider out there could relate. It's slow torture.

Thanks for any help
Brad W

[R100RS]

I feel your pain. I had this same issue with my bike, I hope the reason is the same as yours as it can be fixed.

I noticed the clunk when I test rode the bike before purchasing it. The previous owner acknowledged the clunk but could not identify where it was coming from. It didn't have any effect on performance or handling. The times I noticed it most was under hard braking.

The cause (on my bike) was the worn top triple clamp. The flat piece of metal that the top of the forks bolt to and that the steering shaft bolts to. The piece was worn enough that no matter how tight the bolts were at the top of the fork, the holes in the flat piece were large enough that the forks would shift at times and clunk.

The BMW design of this part is inherently bad, as there is no positive mechanism to hold the fork tubes. I replaced mine with a CC Products piece which has pinch bolts that grip the top of the fork tubes - no more clunk. HOWEVER, I have heard for older bikes that the CC Products designe does not work well. If the fork tube is not completely sealed before it attaches to the bike (it will be in the newer airheads), the CCP piece will not seal the top of the fork tube. If your bike has the older design, there is a company/person out of Seattle (?) that is making a similar top clamp design but which does not have the sealing issues that the CCP piece may have.

I'm not sure about the wobble. Check your steering head bearings and make sure they're not too loose. Hopefully, your clunk is easily fixed, and this may help the wobble, but I wouldn't count on it as mine never wobbled outside of steering head bearing issues (worn out or improperly adjusted).

[jdiaz]

I thought all the early R65's use cast upper and lower triple clamps? My '86 uses the sheet metal version tho.

My bike also has this clunk. Developed right after the front end was rebuilt, which makes me wonder if something was left out.

[rocketman]

had the same thing with my R60/5 I solved that along with the dreaded /5 wobble by a complete, and I mean Complete rebuild, new bearings and races, complete tear down of the forks, replacing all wearable parts, i.e. bumpers, ball valve and spring, flush the inner slider tube with the damping holes, new oil, Progressive springs (cause I wanted a slightly stiffer ride cause of my cornering style:D ).
One thing to check while it's all apart is that the fork tubes are not bent, just roll on a known flat surface.

Once the forks are reassembled and back in place, mount the axle, without the wheel, and pump the lower legs up and down a few times without the oil in yet, they should move smoothly, if not the legs could be out of true with each other. A piece of flat glass held up againist the legs will tell you if they inline with each other.

When rebuilding them and torquing down the cap nuts on the fork tubes DON'T do it by bracing the fork legs or steering stop against something, like putting the wheel between your legs, it can cause the fork legs to get out of true with each other, the best method I've found is to use an impact hammer, or if you don't have access to one, try to use a bar braced between the center tube of the upper tripple tree and oppisite fork leg right at the tripple tree to apply the reverse torque while tightening.

Once I rebuilt it I can load the bike any which way and no clunks or wobbles at any speed or road condition. It's an afternoon well spent. Oh, yes I did also replace the rear shocks with after market as worn rear shocks (as well as worn swing arm bearings) can affect the wobble problem too.

RM