I worked in a multi line motorcycle shop from '85 - '95, and have been happily riding motorcycles and bicycles for many, many years. Not surprisingly, motorcycles experience a similar phenomenon Because of the greater vehicle mass and higher speeds, a simple wobble or shimmy can quickly become what is referred to as a dreaded high speed wobble or "tank slapper". I have a few friends who have experienced the latter -one fair outcome, all the rest terrible. I have only experienced a minor decel wobble on a beloved old "Airhead" BMW myself.
Just as with bicycles, there is no one answer. Correct steering head bearing adjustment is critical, but not the magic bullet. Proper rear fork (swingarm) bearing adjustment,especially on the aforementioned "Airhead" BMW's, frame alignment, tire selection, tire air pressure, load placement etc. are also important to eliminating the problem. (Sound familiar?) Most of the folks I spoke with complained of what is referred to as a decel wobble. That is, after leaving go of the handlebar and as the bike loses ground speed, a slight wobble would occur. This minor wobble can get out of hand quickly if not corrected. The correction is to gently return ones hands back where they belonged. A decel wobble typically occurs around 40ish mph. Having experienced it myself, I assure you I wasn't being flip when I would suggest to folks that there was really no good reason for removing ones hands from the controls of a single track vehicle until it came to a stop. Then I would run through the litany of checks and adjustments that may correct the problem. Some time ago I read somewhere, here perhaps, that a possible technique for eliminating a shimmy on a bicycle was to gently apply pressure to the top tube with one's knee, assuming one could not be bothered to return ones hands to the bars. I can't remember which of my three bikes exhibit a shimmy with hands removed, but the other two do not. In my experience with whichever bike it is, I have found that to be effective in eliminating the shimmy. Of course, not removing my paws from the bars stops the problem from occurring in the first place. For reference, some of you may find David L. Hough's "Proficient Motorcycling" an interesting read. I have been riding bicycles since 1961 and motorcycles since 1966. I always thought I knew what I was doing until I read David's book. I thing you will find that much of the information presented in that book regarding handling readily applies to bicycles. Take care folks. Stan Columbia, SC -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
