Discussion of Tank Slappers–Part 1 (Snowbum)

Since the original publishing of the discussion about tank slappers”, I finished writing an extensive article on that and allied subjects.  This was after accumulating a very large number of tests on a large number of BMW Airheads, mine, and customer’s bikes.  The article is on my website. Here is a direct link:
https://bmwmotorcycletech.info/instability.htm
That article gets more deeply into the subject, fixes some erroneous comments I made or implied in the original, and delves into weaving, wobbling, high speed effects, etc….all are in depth.
I include the link to Gordon Jennings article (Gordon and I spoke many years ago on the subject).  Tony Foale was also contacted.

There is a lot of misunderstanding, misinformation, old wive’s tales, etc., to be cleared up…and, I have done so in the updated article.   In the original article in this Technical Tips section, now removed, I also failed to say anything about rider nor passenger weight testing, among a few other things that are important.  I also failed to EMPHASIZE my comments on rear tire wear, and should have, especially I should have commented about wear of the squaring-off type, particularly since it was one of the longer discussions I had with Gordon on the subject…comparing notes and tests.  There is NO question that a squared-off REAR tire makes tank slappers MUCH more likely to happen under the some circumstances.
I have run tests on later model BMW’s, including Oilheads and Classic K bikes; and, other than the effects of high speed instability moving upwards in speed due to the better suspensions and frames stiffness, things remain the same.

Snowbum
rev:  02/21/2021:   very minor; primarily http>https, but also slight change in commentary, above.
https://bmwmotorcycletech.info/index.html