Hello fellow airheads, been lurking for quite some time, now I have an issue with my, newly acquired 88 RS mono shock, that needs help. My issue is as follows. After purchasing this 88 RS mono shock , and having it delivered, it was a total delight for the first few days of ownership. Then one afternoon I decided to take her out again and enjoy another beautiful day of riding. "As I began my ride entering my first left hand turn I felt an odd sensation through the seat, as if the rear of the bike wanted to go right", while I was counter steering to the left. This did not feel normal to me, and I have been riding for over 30 years, and all on BMW motorcycles. My selling dealer even seemed perplexed, and asked if I had ever ridden a mono shock before. No I haven't, but I've never felt that out of control on my motorcycles before either. Anyone have any ideas where to look? I'm thinking swing arm bearings to begin with, or should they look deeper? Any help much appreciated. Thank You
Long live the Airhead, they are a joy to ride, and their simplicity makes them even better.
I also bought an '88 RS mono-shock with about 80,000 miles (usually described here as "single-sided") which turned out to have handling problems. The only thing to do is push-pull on every piece of the rear suspension using the longest lever available. By that I mean if you suspect the swing arm bushings, then push-pull on the rear portion of the rear tire so that the wheel and swing arm help you get leverage. The correct "play" for every component in the entire rear suspension is ZERO... when applying your full strength.
My issue turned out to be the large rear wheel bearing. This was verified by grabbing the top and bottom of the rear wheel and applying the push-pull test. This test detected about 1.5mm play which could be felt (and heard) at the OD of the rear tire. Replacement of the bearing was straight forward, but not easy. This bearing was well over 6" in diameter and larger than all my pullers. A new bearing and 2 oil seals set the bike right again.
I suspected that the root cause was years of running the final drive low on oil and/or not running synthetic gear oil (which runs much cooler in this application). But of course, that was total conjecture on my part.
[Overall, I was not impressed with BMW's single-sided design. It's not a true "mono-shock design", the layout overloads the rear wheel bearings, the rear suspension travel is limited, and the overall steering ends up being too "quick". Luckily the original owner spotted the bike and offered to buy it back at a premium.]
Hope this helps with your issues.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
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