Greg,
The one K75 that got here with the “customary” Fichtel Sachs forks had been the K75 C and K75T. These had 7″ of journey and (poor) dampening in each legs.
Prior to eight/91 all K75Ss and K75RTs got here with the Fichtel Sachs Sport forks with dampening in solely the left leg and 5″ of journey. The later (89-90) Cs might have had the Kind forks
After 8/91 ALL K75s got here with the Showa forks with dampening in each legs.
The Fichtel Sachs forks had been 41.35mm (1.628″) in diameter with a bulbous mud cowl on high of the slider.
The Showa forks had been 40.95mm (1.612″) in diameter with a normal lip seal on the high of the slider.
Lee, I’m beginning my first dive ever into repairing/servicing the entrance forks and fork elements on a 1987 K75S. I’m desperately looking for the experience that you simply clearly have with Ok bikes as famous by your feedback on the discussion board.
The issue is a arms off decrease pace wobble. l usually checked for minor wobbles whereas driving at decrease speeds with my arms off the bars and had NEVER skilled a wobble within the earlier 34 years of possession. After a significant service, carried out at my native approved BMW seller, I found the wobble on the primary subsequent journey. When bringing it in with this new criticism, they by no means recognized a trigger, nor a remedy.
I’ve scoured what I can discover on-line with reference to this downside on the previous Ok bikes, however there’s not a ton on the market. Step one was wheel bearings, which I eliminated and changed with no change. Essentially the most pertinent video reference I might discover was a selected 3 half collection from an individual named Frank that does go into element on the issue, however the movies are very laborious (for me) to comply with as a reference or information though it is vitally fascinating with the fork alignment discussions.
I’m the unique proprietor of this K75S and purchased the bike at CC Cycle Salvage in Corpus Christi TX in Sept 1986. Very early mannequin, I believe #238 (most likely due to your analysis) of all K75S’s to return into US. It has by no means been in an accident nor the next pace slide, and positively no influence to the entrance finish.
I do not need a ton of mechanical expertise, however have retired, have the time, and I’m constructing extra confidence in jobs I would not have tried previously.
My main guide is the Clymer I purchased most likely in 1989/90 as it’s the 1985-1989 K75&K100 Service/Restore/Upkeep guide. My secondary reference is the Haynes that covers the K100 (2 valve) ’83-92 and the K75 ’85-96. I am not too thrilled with both, particularly the pics within the Clymer, however the Clymer undoubtedly goes right into a a lot higher element.
Listed here are a number of questions for you for those who please:
Which is your favourite guide for the K75S?
I’ve seen the fork dialogue, and others, that you’ve got contributed your experience. I’m virtually 100% constructive I’ve the Fichtel – Sachs within the unique ‘S’ configuration as my L fork has the “S” (with 3 integral dots) stamped on the slider, not close to the fill cap on the tube. The appropriate fork doesn’t have the “S” stamp on the slider. Each of the risers have “Brembo” stamped on the slider close to the brake mounts, and the fork slider serial numbers are sequential, 1 454 325 and 1 454 326.
My present subject is I’m making an attempt to take away the fork high cap, web page 380 if in case you have the Clymer guide that I do, and I can not compress the highest cap by hand far sufficient with a socket/drift to take away the snap ring and begin eradicating the interior elements….to get the slider to a paint store. I do not assume I missed a step within the guide as I’ve learn it most likely 20 instances, so do you may have any recommendations to get the slider off the fork tube?
Lastly, there gave the impression to be an inordinate quantity of fluid within the left fork, which is the “sport” fork with the shorter journey. Any fluid in these forks was modified at a seller, or at a man named Stan’s store in suburbia Philly. Stan was a tough ass, however he used to race Beemers and he was a superb mechanic.
I’m going to measure the quantity of fluid after it’s absolutely drained. If the fluid stage was too excessive, might that be a possible trigger for a wobble? Additionally, I’m not too acquainted with fork fluids, however the drained fluid regarded good, not cloudy or pungent, and was a purple shade. Any concepts of the model/viscosity with that shade?
Any assist can be drastically appreciated! Additionally, greater than seemingly this isn’t the final communication from me. Thanks in your time Lee, Ross V Velardi
