From: AskOak@aol.com
Subject: Wobbles, Weaves, Tank Slappers
Date: Wed, 31 Jul 2002

Hedz:

The past several days on this topic has resulted in a host of opinions ranging from almost agreement to diametric opposition. It needs some clarification. There is a lot of flesh at stake… The causes and cures have been published in AIRMAIL tech pages more than once and many years ago in BMW News in the late 1970’s in feature articles on the subject. But for you neophytes and latecomers here it is in a nutshell……

1. First and foremost, never let the problem manifest into a worsening condition. The progress from normal handling to dangerous deterioration is usually slow. Don’t ignore the warning signs and get it fixed before it fixes you so nobody can fix you. You will usually get some early warning signs before the big event of the tank slapper happens.
2. The tank slapper is of course the worse, almost always preceeded in miles and time with a lesser degree wobble mishandling. Weaving is an entirely separate phenomenon.( discussion forthcoming)….
3. The most dangerous combination for the wobbling and tank slapper is a handlebar mounted wind screen arrangement, a solo lightweight rider, a significant load at the rear of the machine rear of the rear axle, diagonal headwinds, and of course, steering head bearings too loose or worn and notched. The more of these ingredients in the act, the greater the chance of disaster-and the event may happen without warning.

The primary instigation of wobble is a physical resonance set up in the frame and steering geometry that once starts, feeds the accumulated resonant energy back into itself to accentuate the problem. This is what makes it so difficult to squelch once commenced. A rigid frame and steering coupling (tight steering head preload) will avoid the resonance,by absorbing the energy needed to create and manifest the problem, but a small amount of liberty in movement of the steering is needed for continuous self correction of tracking versus road aberrations as the machine moves along. The proper preloading of the bearings is a compromise-to allow enough movement for corrective needs and not so much as to allow resonance to initiate. Kind of a tightrope act.

If you incur the tank slapper, the name of the game is to make every move you can to inhibit the resonant energy feeding the monster. Bodily moving forward (shifting your weight) as much as you can may help. Do NOT speed up. Avoid the front brakes while the wobble is in effect. Suppressing the resonance is the name of the game. If you are strong enough and can get hold of the bars without having them fling you and you can hold them still and squelch the resonant energy that will likely help. If you get the machine under control and can come to a stop, go clean out your pants.!!

Randy G. posted a memo quoting his motorcycle mechanic saying the way to negotiate a wobble is to speed up lighten the weight on the front wheel. WRONG. That is exactly what you do NOT want to do. It has been reported and makes valid sense that machines that wobble solo won’t usually do it with 2 up. That is because the extra weight and force downward on the front wheel has a slight effect of more preload on the steeringhead bearings and also increasing the mass that must be slung around during the tankslapping event. The resonance doesn’t like that and sees it as a damping mechanism thus may refuse to support and may suppress an existing oscillatory motion.

Loading heavily rear of the rear axle is dangerous in that is lightens the load on the front wheel and steering preload thus enhancing the conditions for resonance and oscillatory motion of the front end. The handlebar wind screen is taboo in that too will enhance the tendency for front end resonance especially with gusting winds hitting the screen at an angle. There are ample reports in my files to corroborate that from years gone by where some of the riders crashed.

With all that being said, you know now what NOT to do. Prepare your machine for maximum protection via the laws of physics. Then make sure your steering bearings are not notched and properly adusted. Actually, if installed and adjusted properly initially, they NEVER should need readjustment later on. Hardened bearings in the steering do NOT wear. They may get notched from many miles and lack of motion. The subsequent maintenance step is usually replacement rather than adjustment.

For those that really do require adjustment, it is quite simple. Place the machine on the center stand and see how easily the bars move from full left to right. If they flop easily from center either left or right to the stop with a clunk, the bearings are too loose. They should be snugged until the bars do not flop but will seek the limits left or right with just a tiny bit of help. If too snug you may experience a slower speed weave with a sensation somewhat like in a rain groove. That is not particularly dangerous but the machine is telling you the steering is not able to self correct while in motion. This affects tracking ability and gives the weave sensation. That is a signal to loosen the steering preload slightly. When you have it correct the machine will track without weaving and refuse to wobble provided you have taken the other proper precautions as indicated. If you do it all correctly you will likely be lucky and never incur the wrath of a tank slapper. Now go do your thing if needed..

Oak-ABC #35

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From: Bill Harris
Subject: Re: wobbles, weaves, tank slappers
Date: Wed, 31 Jul 2002

>From: “R. Fleischer”
>
>Bill Harris wrote:
> >
> > Uh, does this mean I shouldn’t use the /5 damper on pavement?
> >
>
>The steering damper is not REALLY meant for solid pavement. It is a
>stabilizing device, whether friction or hydraulic, for conditions
>involving sharp little problems such as modest rocks and pavement
>edges, etc….in the dirt…gravel, etc.
>Where I DO use the damper on the street…so to speak anyway….is
>over bridge gratings.

Live and learn. Even though I’ve ridden this bike for almost 30 years, I never knew that. I’ve always cranked in a ~very slight~ amount of dampening, mainly because the damper was there. OTOH, I can tell when I have too much dampening applied– the handling gets real piggish and doesn’t feel “right”.

I’ll leave the _status_quo_ for right now, but after I check the steering bearing adjustment I’ll zero out the damper.

–Bill Harris
ABC#6223

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From: R. Fleischer
Subject: wobbles, shakes, tank slappers…MORE…and lengthy.
Date: Wed, 31 Jul 2002

Well, we are well into (through?) a thread on the dreaded tank slapper. Earlier, I gave some of my ideas, and just this morning I received Oak’s viewpoints on the loading of the bike and windscreens’ effects, ETC. Good stuff. I have one last posting here on this subject.

All sorts of various instabilities, strange feelings, whatever, come about not only from the initial design, but from wear and tear on everything from tires to bearings. Loading effects have the biggest effect, assuming that tires and steering head and swing arm, shocks, ETC., are all reasonable. While my posting dealt with slow speed weaving and high speed wobbles including tank-slappers, I hardly got into the subject in the depth I could have. My comments were based on a number of decades: experiences, my own, my customer’s, my friends; and, a LOT of motorcycles I have worked on….and test ridden. Some of the tested bikes were unbelievably bad…no wonder their owners complained. Most all of the time, our bikes just keep rolling up the miles, with no problems. I do want to caution you all though…especially if you intend to not read much farther….Avoid wearing your rear tire flat across and then carrying weight in the saddlebags and scoot boot (trunk)..if you have those. Fairing makes it all worse. Keep in mind Oak’s comments.

I have read many a scholarly report over the years about handling, weaving, oscillations, and the like. The ONE report, an article in Motorcyclist of July 1995, by Gordon Jennings, is the one I like the best…because it is an easy read for all, and covers, very nicely, wobbles, weaves, wallowing, wiggles, flutter, shimmy….and…tankslappers and what he referred to as the Capsize Mode. This is probably long out of any print medium and likely unavailable…don’t really know. I do have a copy. Here are a few highlights:

1. Transition to a straight-line serious weave mode is gradual, with plenty of warning.
2. Motorcycles do NOT go into big wobbles for no apparent reason.
3. The foundations for most of the Post-WWII theoretical studies of motorcycle stability, as done by Prof. R.S. Sharp (England) are still with us.
4. Wobble is best thought of as flutter or shimmy, the frequency of which is 6-10 Hertz.
5. Weaving is more a coupled roll/yaw motion of the entire motorcycle.
6. The type of weaving Jennings talks about is normal, it is inseparably a part of the motorcycle’s keeping itself upright, and most weaving is not really felt, it has a frequency of 1-3 Hz, and usually LESS than a single degree of handlebar movement. Weave comes because the motorcycle is always wanting to tip over, and is righting itself.
7. Weave tends to gain amplitude with speed…and can become thrilling at about 100 mph….ESPECIALLY!!…if you are riding a full-dressed motorcycle. The fairings, baggage, ETC, make things FAR worse! This is the reason the manufacturer’s advise against high speeds with that equipment.
8. Jennings was part of a series of scientific testing.

Jennings had a LOT to say about various testing programs done over the years on this stability subject, some of which he was personally involved in. One of his notes was on the early Japanese bikes that had what he called Cornering Wobble…a weave-mode wiggle that appeared at about 60 mph and above…the threshold of which came from speed and lean angle combination…coming from small angles of lean if you were fast enough, and VV if cornering hard enough. MANY of us old timers remember those bike’s handling ‘problems’. In fact, Jennings wrote the technical paper that was published in CYCLE, and that went to the Society of Automotive Engineers publication (SAE) on cornering weave. He blamed poor damping of shocks for the most part. Those that have been around a LONG time may well remember Honda’s “FVQ” designation for its shock absorbers….and us riders who facetiously said that FVQ meant Fade Very Quick (‘Japanese manufacturer’s ONLY put oil in the shocks to keep the seals from squeaking’). Wasn’t much time after those comments that the Japanese manufacturer’s wised up.

Keep in mind that the testing at Willow Springs was done with fully instrumented bikes…sensors, strain gauges, all the fancy data-gathering stuff.

These tests I mentioned went to the extreme. They even arranged to have a saddle bag lid fly open (no problem). Lots of bizarre testing. Testing for overweight riders produced no problems. Tire and wheel runout generally produced no real problems. Loosening spokes on ONE side of a wheel had little effect. They tried chassis misalignment. They experimented with steering dampers. The only comment of serious note on dampers is that if adjusted too tightly the bike could not make the needed small self-corrections, and some riders found themselves heading for the ditch.

There was quite a bit on fork braces. The comment that fork braces were devised by race mechanics back when skinny forks had to carry the big twisting loads of was true. The comment area noted that the SECONDARY effect of a fork brace might well be making WEAVE slightly WORSE.

No surprises were found by changing tire pressures, nor really LARGE imbalance weights on the rims.

So, what are the truly pertinent things to know from that long published article?

Well…here it comes folks:

ALL…100%…of the testing, of all the various makes and models of bikes… …showed that the touring configured bikes were FAR worse. They shimmied more, weaved more, had real instabilities at various speeds, ETC. They exhibited coast-down shimmying (gain amplitude as speed decreases, until it suddently stops). Cornering weave was made quite worse by placing even small weights in the saddlebags. The conclusion after all the tests was that:

1. fully dressed motorcycles can be very bad in stability at speed
2. any weight in the saddle bags adds to the instability
3. the WORST place to have weight was the rear trunk
4. weights on the ends of the bars would eliminate coast-down shimmy.
5. ***surprising conclusion…this one: *** The VERY worst combination, by FAR, was a big load in the scoot boot…and..a rear tire worn straight across the tread face (that flat road only type of wear. NOTE that THIS is the TYPE of wear that a big touring rig shows most of the time!

A lot of testing was done with various tires and tire wear. In EVERY instance, a flat-worn rear tire was a real trouble causer.

Gordon stated that the ONE type of bike that scared ALL of the test riders, was a fully loaded dresser, with some decent weight in the saddlebags and the trunk….that this type of thing ALWAYS, on EVERY test bike, produced a high-speed cornering weave that freaked all the riders out. ((note from me: the SPEED at which this happened was pretty high…MOST of the time, but in some cases fairly low…like 50 mph)). (those wanting to know what the scoot boot weight was: a case of beer!).

One of the tested fully dressed rigs had a weave-mode just perceptible at 85 mph, and THEN staggered back and forth between two full traffic lanes at 118 mph…yet, Gordon pointed out, riders invariable SAID that things came on ‘suddenly’ and ‘without warning’….yet ALL the testing showed that early warning signs abounded in EVERY CASE. The testing included any effects of longer handlebars, weight of one’s arms on the bars, tail trunks, two-up, and almost anything you could dream up. The testing was done for the engineering department of the University of California at Davis, under Professor Dean Karnopp, and all the testing was done to see how real-world testing compared to computer modeling. Karnopp is hardly a type whose head is buried in academia. Testing was done at Willow Springs Racetrack.

I have driven a fair number of miles on fully faired bikes, mostly with saddlebags, and a few had trunks (scoot boots). I have ALWAYS noticed high speed weaving….that TENDED…on the airheads….to start up around 85 mph. Obviously, many of these miles were on such bikes with a flat-worn rear tire.

I tend to think that Jennings…and our Oak’ comments…are correct…mine too. Many of us tour with rather outlandishly loaded up bikes.

Let’s be cautious out there.

da Bum.
OK, I quit this thread.
#1843

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From: Speedmonkey123@aol.com
Subject: tank slapper & steering dampener
Date: Wed, 31 Jul 2002

My R90 had a tendency to develop a slapper at about 40mph going downhill in a sweeper no matter what I tried (i.e. new tires, balancing, new shocks, load balancing, head adjustment, wheel bearing, and on and on). Scared the hell out of me a time or two. This went on for years. I was about ready to get rid of the thing. Finally had a look at the steering dampener. Took it off. Slappy went away and never returned. Steering dampener is at the bottom of the Flagstaff dump. I never seemed to need the darn thing anyway.

Ray #5006

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From: Bill Harris
Subject: Re: wobbles, shakes, tank slappers…MORE…and lengthy.
Date: Wed, 31 Jul 2002

Good thread, and good comments by all. I look at this phenom as DEADLY and compare it to a “death spiral” in a airplane. You’re buzzing along as happy as can be, and suddenly things go to hell in a handbasket and you are headed towards the ground and there is little time or altitude to do much of anything.

I wonder, though, if there is an operational difference between an “outlandishly loaded up” bike, and a bike ridden two-up? Clearly, the total weight and weight distribution appear to be similar.

For my own packing the bike, at this point in time, I strap 2-3 Helen bags on the passenger seat, use a 20L tank bag and Windjammer fairing storage. I have a luggage rack, but when I put a tail pack or travel trunk on it, I tend to pack light-weight, high-volume items there, keeping as much weight as I can off the extreme tail-end. No saddle bags/side cases. When I change the package weight or the weight distribution, I will do a mockup and take the bike on a non-trip test ride to be sure all is well. Thus far, she’s been stable and runs arrow-straight.

–Bill Harris
ABC#6223

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From: Ed Hook
Subject: Re: wobbles, weaves, tank slappers
Date: Wed, 31 Jul 2002

>All the bmw’s I have owned wobbled. My old 76 XS650 never did.
>Alex

At about 55mph I hit a wicked pothole hard enough to knock my mirrors out of wack. Three oscillations and Jake righted himself. Whew.

I bungied a toolbox on the rack once and headed off for a tech day. Two houses down the street I pulled over- Jake was wobbling so bad I thought my back tire was flat. Nope. It seems the rack is a horrible place to carry weight.

Ed

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From: Bill Shockley
Subject: Re: Tank slappers, a different viewpoint
Date: Wed, 31 Jul 2002

Hi Ben,
I guess all old bikers have their riding defense mechanisms to fall back on for any bad situation and I call nobody’s into question. It almost gets to be an instinct. If it weren’t for them we would have all been dead long ago. Bill.

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From: Ben Barkow
Subject: Tank slappers, a different viewpoint
Date: Wed, 31 Jul 2002

It is always an education to read Oak’s views and especially on the serious matter of front wheel oscillation. But I would like to add my 2 cents worth, differing in some ways from his analysis.

We are talking about oscillation of the front wheel and steering assembly. Oscillation means resonance, once triggered, peaked at a point, and insufficiently damped.

My experience is that the resonance is triggered by wheel imbalance. Wheels go out of balance in time, have poor rims sometimes (lots of the time with wire wheels, I’d say after 33 seasons), and initially are often poorly balanced. This is often the case as with the fixing method of dynamic balancers (such as the fellows at Trenton) which essentially are balancing on the thimble-shaped spacers as centered by the seals and securing mechanism. Obviously not right… and you know how keen I am about good dynamic balance.

My advice is never leave the crucial issue of front wheel balancing to anyone but YOU. Static balancing works fine for a motorcycle wheel and can be done perfectly well with two chairs, a piece of chalk, and some heavy solder wire.

Damping is a result of front wheel loading on the pavement, which as Oak points out, is diminished by rear-weight distribution. Vastly more friction between you wheel and the concrete than in the head bearings. Also by friction dampers (I hate to say a good word for these stupid things) and, absolutely wisely and soundly, by hydraulic or other capacitative impedances (which as Snowbum urges, have major shortcomings for drivability otherwise). The steering head bearings and general frame stiffness, in my view, do not have much to do with the damping and perhaps, are of only secondary importance in any other aspect of the resonance or tank slappers.

There is no surprise in stopping the oscillation: grab tight and be awake enough to do so early. Oscillations are easy to trigger and normal (they and their triggers are ubiquitous in rotating machinery, just like germs in the air), but the simple weight of your essentially-dead arms and normal muscle reflexes keep them from getting peaked and building up.

Being traumatized into inaction is not smart and yet is the thrust of the List discussion so far. Or doing something weird like accelerating to a higher speed of wheel rotation in order to pass-through the resonance frequency can work but I don’t think I would try it! Cheers.

Ben Barkow, Toronto, ABC 5067

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From: Bill Shockley
Subject: Re: Tank slappers, a different viewpoint
Date: Wed, 31 Jul 2002

Hi Ben,

I was one of the people who advocated immediate acceleration for the shakes but maybe I should clarify what I do if an oscillation starts.I wack the throttle open momentarily followed by hard braking with both brakes while steering for the side of the road. I am not sure why this works except that it is like slapping your bike silly. It is a violent action and it stops the shake. Try it on a straight road a couple of times and you will see what I mean. Once you get stopped you need to look for the cause or change something. Moving luggage around or changing tire pressure are two good things to try but they were never really the problem for me. I have always found the problem to be in the steering head seen as loose bearings or a bent frame/forks. The only tank slappers I was ever in were on dirt bikes and they resulted in crashes. That’s my story and I’m sticking to it.

Bill.

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From: Ben Barkow
Subject: Re: Tank slappers, a different viewpoint
Date: Wed, 31 Jul 2002

The reason speeding up DOES help is because you leave the rotational speed at which the oscillation peaks. The oscillation starts as you are accelerating and so it is the normal first and fastest reaction to continue to ramp up the speed. And that does help and you may not go into oscillation on the way back down into the unstable wheel speed… or you just might… but you are then ready for it.

I agree that a whole lot of looseness in the steering and frame con contribute, with bent forks for sure adding a weird coupling to the rotating system. Also, as you say, having wrong air pressure sure has an effect on the resonance of the wheel. And, as you say, dirt bikes can have this problem (especially on highways, because they have less trail) a sure misery.

But as Oak says, it has lots more to do with non-chassis-mounted windscreens and rear-wheel weight. I forgot to mention that the weight also modifies the steering geometry which might pull you into the resonant range. I sometimes found my R69s would hint that it wanted to go slappy when the rear height setting was high.

Ben

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From: Joe <‘\(\(\(\(\(><
Subject: MSF, factors, observations re: Surviving a Tank-slapper
Date: Wed, 31 Jul 2002

The short answer would be what you’d find in an MSF student handbook:

“Wobble/Weave — These are related but distinct handling problems usually caused by excessive weight in the wrong place or mechanical problems. A weave is an oscillation of the rear of the motorcycle while a wobble is a rapid shaking of the handlebar.

“The difference is academic since the solution is the same. Keep a firm hold on the handlegrips but don’t lock your arms and fight them. Ease off the throttle as you move your weight down and forward.

“And don’t believe the ‘old timer’ show say to accelerate through a wobble. It doesn’t work.

“If you can’t determine the cause (such as incorrect loading or improperly adjusted suspension), take the motorcycle immediately to the dealership.”

FACTORS: Here are just some of the things that can precipitate or worsen wobbles, weaves and tank-slappers. The bike cares not how many factors are involved (1 or 20, no diff), only that when the sum meets the critical mass and altered geometry for one, it dances.

FACTORS: Here are just some of the things that can precipitate or worsen wobbles, weaves and tank-slappers. The bike cares not how many factors are involved (1 or 20, no diff), only that when the sum meets the critical mass and altered geometry for one, it dances.

• Wheel, steering head and or swing arm bearings that are out of spec (preload, condition, alignment, etc.).
• Out of spec steering and or suspension dampners (forks, rear shocks).
• A bike that loaded or adjusted for such improperly. This includes improper weight distribution front/back, side/side and by height (the ideal is low and centered).
• Adverse tire wear, pressure, alignment and or application philic to W.W.&T-S.
• Adverse aerodynamics including, but not limited to, handle bar mounted objects (windshields, fairings, blankets, jackets, tool-rolls, etc.), saddle bags and backrests (esp. pass. ones).
• Road conditions like grooves, gratings, tar snakes, etc.
• Rake, trail, wheelbase, center of gravity, proximity of mass to the CoG and other geometry factors.
• The one thing you forgot to check (listers will/have chime[d] in).

OBSERVATIONS: Ever look at that one wheel on a shopping cart that flutters? Notice that when you shift the weight to it, it smoothes out? Remember how a MC’s traction is used to either change speed or direction? Remember that a skidding tire has less traction than a rolling one?

If the weight is loaded to far back on a bike, the front tire has less. When if flutters like the shopping cart wheel, do you want to speed up and shift more weight AWAY from it (run down the supermarket aisle and watch the wheel)???

W.W.&T.-S.’s cause BOTH tires to scuff more than normal. Scuffing can be thought of as skidding-lite, hence less traction. When traction becomes less avaible, do you want to be in a turn or romping on/off the throttle/brakes???

Imagine a less-than-perfectly-maintained bike with a handlebar mounted windshield and toolkit, a narrow front tire (small footprint for traction), saddlebags, fully-loaded sissybar-mounted tailpack running through hiway sweepers with dips and whoops. Yeah, exactly.

I USED to have a small handlebar-mounted windshield, but now ride naked. I still get a weave (pre-wobble) at certain speeds with my saddlebags when I pass a semi on the hiway. The wind can catch one bag, push it behind, exposing the other bag more, then push that one, re-exposing the other…. wobble. I’ll back off the thottle, adjust lane position to a less turbulent zone, shift weight forward, all in a smooth controlled manner much like Carol described Charlie Baker doing; and then I’ll setup and “punch” past the semi in a way to minimize the time exposed to the semi’s turbulence. When I did my BunBurner Gold run (1,500+ miles in 24 hours), I purposely rode s-bagless with only a tankbag and paperbag bungee-netted to the back with extra oil and some sweats and had NO wobbles, hmmm.

In the the very near future, I’ll ditch my Reynolds back rest (very nice to bungee-net groceries to but a – factor on the highway). I also have plans to incorporate some Aerostich tank panniers to get more of the “luggage” weight down from the tankbag/pillion-seat and forward of the saddlebags while also better deflecting some of the wind of my legs and, more importantly, the face of the saddlebags. I also make a conscious effort to keep denser items in my saddlebags lower, more forward and closer to bag mount cavity.

Any help to you, Bill?

Joe 70cuda@email.com
ABC #3335

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From: Ben Barkow
Subject: Tank slappers and weave/wobble are very different
Date: Thu, 1 Aug 2002

While tank slappers and weaving have some over-lapping causes and cures (as Joe Cuda, Snowbum, Bill Stockley, and other wise persons have pointed out), they are very different in character (as the same people may have also pointed out, sort of).

1. Weaving/wobbling/path hunting is a normal and necessary activity of self-correcting systems, like bikes, cycles, and airplanes. If you don’t hunt (and have an “error signal”) you can’t correct. This has to do with the longitudinal line of travel and gets more wonky when, as Bob says, you have a case of beer in your scoot boot and other means of rendering the bike ungainly and doing harm to the center of gravity or center of rotation of the bike. In that case, the hunting gets wilder, but remains normal and, hopefully, self-correcting. “Normal” in a feedback sense, but not “normal” when you are leaving your own lane of traffic and heading into the opposing lane before self-correcting back again.

Snowbum went into detail about factors which are known to influence the weaving process which is normal but usually small in amplitude (like fairings). But sometimes different factors relate to tank slappers.

Sometimes things go beyond the self-correcting and there can be weaving and wobbling which are not self-correcting and the yaw may go into oscillation.

2. A tank slapper, as I imagine the concept, is a resonance of the rotating system of the front end. Building on Oak’s eMail, I tried to explain in my earlier post, you have resonant frequency issues and damping issues. (The technically minded will recognize that I have glossed over phase relationships.) My impression, contradicted by others, is that wheel operations (balance, bearings (which I forgot to mention), rims, dynamic/capacitative dampers, rider behavior, and to some extent, head bearings) are the main culprits here.

Cheers.

Ben Barkow, Toronto, ABC 5067

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From: William Harvey
Subject: wobbles and tank slappers
Date: Fri, 2 Aug 2002

The thread on these has been quite interesting. I can see how speeding up might stop them but then again. My first near encounter with a hi-speed wobble was shortly after I started riding back in 1976. My first bike as a Honda CB500T. Being young and stupid, as opposed to old and stupid, I decided to see how fast it would go and what it felt like. Didn’t have anywhere near the experience needed to ride that fast but like I said I was young and stupid.

I took the bike out on a nice straight county road and opened it up. I got up to a tad above 90mph indicated and figured that was fast enough, even though I had just a little bit left. As I was slowing down, when I got to about 75 the wobbles started. Scared the heck out of me. I speeded back up and they stopped. So here I am hauling a** down the road. If I slow the bike acts like it is going to throw me but I know I can’t stay that fast forever.

I went for broke, hit the wobbles again, as I slowed they kept getting worse but thankfully stopped about 65 or so. At that time I had one of the Bates handlebar fairings and figured that had caused the problem. I re-adjusted it and never experienced that again on that bike.

A little over a year ago I had a mild one on my airhead. I was in a down hill sweeper and it started. I slowed down and it stopped at once. I didn’t have much of a load and have since changed my fairing. Hasn’t happened since so hopefully I won’t see it again.

William Harvey
ABC#6392

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