• Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password.

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?

  • Beginning April 1st, and running through April 30th, there is a new 2024 BMW MOA Election discussion area within The Club section of the forum. Within this forum area is also a sticky post that provides the ground rules for participating in the Election forum area. Also, the candidates statements are provided. Please read before joining the conversation, because the rules are very specific to maintain civility.

    The Election forum is here: Election Forum

Famous Dunlop video on Wobble and Weave

motormike

Member
Considering the controversy surrounding the high-speed handling of the the K1600GA and K1600b, I thought I'd post a link to this famous old Dunlap Tire video discussing wobble and weave handling issues. If you haven't seen this video do yourself a favor and watch it. While dated and poor quality video, the information is priceless. Some cool footage of vintage 70's Japanese and a BMW R90S as well! You can skip ahead to the 4:05 mark where Mr. Walker starts to talk about wobble and weave handling issues on motorcycles:


https://www.youtube.com/watch?v=fvsDIq3WwVA
 
Interesting. Those riders had big brass "you know what" to ride with that bad wobble at 85 MPH!

I had only one motorcycle that would do the high speed weave. It was a Harley bagger and around 105 MPH it would go into a weave. Not as extreme as those on the video, but around 1 cycle per second. If I kept on the throttle I could ride through it and it would clear up my 110 MPH. I never worried about it as I didn't ride that fast very often.

Every HD bagger I have owned will do the low speed, no hand wobble on used tires. New tires and it would clear up.
 
In the video they are riding naked bikes in a full upright position, which puts less weight on the front wheel than a lean forward position, and also further lightens the front and loads the rear at higher speeds. I would never ride in a full upright position without some type of windshield or fairing to reduce upper body loading at speed. Secondly, he says nothing about maintenance of fork head and swing arm bearings both of which can induce weave and wobble if out of adjustment. Most of the bikes in this video all have some type of non-adjustable swing arm bushing and only partially adjustable ball-bearing fork head bearings. I've seldom had either problem with any bike in my lifetime of riding. That includes the infamous short swing arm /5's which some claim can not be made not to wobble, but I've found they will ride just fine if properly set up. So, I doubt the claim that all bikes will do one or both either.

However, while working at a BMW dealership when the /6's were current we had a new out-of-the box R75/6 that would weave (not wobble) at between 75 and 80. I was the young guy without wife or kids so I go to test the devil bikes. :) We adjusted everything on that bike to speck to no avail. Finally I called the Butler & Smith West Coast service center where I'd gone to service school and I talked with the very German direct from BMW AG service manager who had also been my instructor. Right from the start it was our fault that this new bike didn't ride out correctly. He rattled off a list of all the things we should check, and to each I would said that we had checked that, to which he would reply "It can't do that" and say that we hadn't done the work correctly. (Sound familiar?) So, in the end all the help I got was to be told that "It can't do that" and it was our fault that a brand new BMW didn't ride out correctly.

About four days later, a box comes addressed to me from Butler & Smith. In it is something I've never seen - a hydraulic steering dampener retro fit kit for a /6 BMW. It had a plate at one end to replace part of the mechanical friction dampener, and a U-shaped piece with two hose clamps to attache the dampener rod to the left fork down tube. All pretty obvious how to install, so we did, and the bike rode out perfectly at any speed. However - and this is the interesting part - there was no paperwork with this kit. Nothing. No proof this hadn't fallen from a stray UFO, and we were never billed. However, the next order of /6's we go in had the frame bracket already welded on, and the one's after that had the hydraulic dampener installed. Go figure.
 
Back
Top