The speed wobble (AKA, death wobble), and how to handle it.

[TimmyJ]

The most frightning term to bikers is probebly "speed wobble", as any of us who have experienced the dangerous perdicament will tell you. The main culprit is the front wheel pointing in the wrong direction as the bike is moving forward (usually caused by the tire leaving the ground and then reconnecting, pointing the wrong way like a wheelie or a pot hole), causing the entire bike to go "out of balence" and then go into a wobble. This out-of-control motion is extremley hard to recover. I myself had an experience, back in 1983.

I was riding my green Honda CB360 up a country road doing about 60 MPH. I had a car infront, and one behind. I took my eyes off the road, looking at some dark clouds moving into the area. When I looked back to the road, my front tire had gone off the road onto the shoulder, where there was a 3 inch drop-off. Either my front tire came down crooked or the soft gravel caused it, but eithr way the bike wobbled violently, at about 60 MPH.

The shoulder and road were even after that, but it was too late, I was trying to maintain the balence, but realized I was about to lose it. I was thinking about diving off the bike toward the shoulder (I had zero protection on), thinking that would be better than being on the asphalt, risking road rash or worse, a car hitting me. However, I just kept off the brakes and off the throttle, and kept my body centered and the handlebars firmly gripped, but did not try to steer it, rather I let the front do what it was doing. Somehow, I miraculously came out of it! I know the odds are almost zero of coming out of a wobble, and I felt very fortunate. Again, this was in 1983. I soon after sold the beloved CB out of fear. I hadnt owned a bike again until 2 months ago when I bought my 750.

Recently I told a motorcycle policmen this story, and asked him what you do when in a death wobble. He said I did the right thing, but he suggested the REAR BRAKES are also ok to get on (not the front brakes though). But he said he wasnt sure about that, it was more of a guess!

Question: have any of you experienced this terrible phenomonah, and is there any known way to get the bike back under control?

[Bumblebee]

I've done it way too many times on soft surfaces. The best solution I've run across is to get the weight aft to unload the front tire, relax the death grip on the handlebars and let it search for stability on it's own then dump the throttle and let it slow until it's under control again or stopped. Frigging street tires are completely total useless garbage crap junk on soft sinky dirt/gravel/sand. If the surface is too sinky, you either maintain way way too much speed and stay on top of the surface material assuming it's flat or sink down and dump it. Sometimes you're going down whether you like it or not.

On pavement I've only had it happen while standing on the pegs with my center of mass way forward near the triple T. Dumbhead rider behavior really letting the rear tire get that light. Again, get the weight aft onto the rear tire and it instantly recovered. The way it started wobbling, I think if I touched either brake, it would have loaded the front tire and unloaded the rear further and made the situation far worse.


Actually the most frightening term is high side. There is absolutely no good can come from that. I would rather take a low side front tire washout event than to be ejected into a ballistic trajectory.

[TimmyJ]

So your saying put weight on your back tire? And it is ok to use back brakes? What do you mean "High side"? BTW, I instictavly held tight, but not too tight.

From Wiki:

Wobble, shimmy, tank-slapper,[1] speed wobble, and even death wobble are all words and phrases used to describe a quick (4 - 10 Hz) oscillation of primarily just the steerable wheel(s) of a vehicle. Initially, the rest of the vehicle remains mostly unaffected, until translated into a vehicle yaw oscillation of increasing amplitude producing loss of control.

An example:

[Bumblebee]

The times I've been in trouble, I never touched the brakes and didn't even consider it. There was too much weight on the front tire to start with which was blatantly causing the primary problem. Each oscillation stepped further right/left than the last one. Any braking would have increased front tire traction which would have eliminated any chance to get it under control again.

I've had the same problem many times flying airplanes and the solution to stop it was to unload weight from the oscillating front tire. The first time it happened on the motorcycle my instinct was to unload the front tire which on a motorcycle means getting the CG aft. So far so good. I still dump it when the surface is just too sinky for the low traction street tires with insufficient velocity to stay on top of the surface.
I'll tell you one thing though, it's no fun at all when you're going fast enough to stay on top and under control on the surface and unable to slow down without faceplanting.


A high side is a locked rear wheel that is released after the wheel steps out sideways event. At that point the rear wheel violently jumps to the other side then jumps back to the original side. 2-3 times of that increasing in amplitude and it ejects you over the handlebars into a ballistic trajectory then the motorcycle tries to hit you in the head as it goes end over end. It doesn't get much more violent than that.

[ariwhiteboy]

+1 to BBs advice...brakes don't really help the situation here. A real "tank slapper" speed wobble is very scary, gentle throttle application may help. Kind of like a car in a skid, it's best not to fight what the bike is trying to do, just go with it and gently try to get it under control.

P.S. Start wearing the gear...it makes bailing a much more appealing option.

[TimmyJ]

I see a lot of sportbikes get the wobbles...I wonder if it has anything to do with the fact their front forks have almost no rake?

[ariwhiteboy]

That combined with the fact that the power to weight ratio allows front wheel lift with only the slightest application of throttle.

[Bumblebee]

I see a lot of sportbikes get the wobbles...I wonder if it has anything to do with the fact their front forks have almost no rake?

That's likely. Hunched over with the riders center of mass forward of the seat area and unable to move it aft without letting go of the grips won't help either.

[Adam Roby]

Interesting conversation...  you will often see a rider get dumped and then the bike continues to go upright by itself for some time.  This might suggest that fighting the wobble makes it worse, letting it do it's thing potentially better.  I have not had this happen enough to remember what I would or could have done.  I once had the rear end skid out because it spun on a painted wet surface, letting go caused it to want to throw me and started a wobble and if I remember right I gunned it and recovered.  Not sure that was the best option considering it all started with the rear spinning.  Scary situation...

BB ->  Is there any known parking lot training you can do to practice this or is it just too dangerous to even consider?  It would be a good thing to learn how to get under control, even if it does not happen very often for the majority of riders.  I wouldn't want to dump her on purpose for the sake of learning.

[TimmyJ]

Right, that's what I did...I "let it do it's thing". Now that BB metions it, I think it was hitting the soft gravel that caused it, more than the pavment drop off. I was then straddling the level line between the shoulder and pavement while I was wobbling, spending a lot of time in the shoulder part. I gripped the handles tight but not too tight, and didnt really fight the steering...rather I was just (instictivley) holding on and let the steering do what it was doing and just kept my body centered as best as possible.

I think your question to BB is a good one...is there a way to practice this so we can become profeciant at getting out of it?

Little things like "do we lift our legs up? Or do we lean back? Or does a "tap" on the rear brakes help? Im just wondering of there is a set "pro maneveure" that we can all learn to get us out of it, if it strikes?

A high side is a locked rear wheel that is released after the wheel steps out sideways event. At that point the rear wheel violently jumps to the other side then jumps back to the original side. 2-3 times of that increasing in amplitude and it ejects you over the handlebars into a ballistic trajectory then the motorcycle tries to hit you in the head as it goes end over end. It doesn't get much more violent than that.

High side wobble


Yes, much quicker than a front wheel wobble, no time to do much of anything.

[Bumblebee]

Is there any known parking lot training you can do to practice this or is it just too dangerous to even consider?

I'm not sure about a specific slow school practice you can do for this kind of thing. I kind of make it up as I go along based on experience and limit it to my chicken factor.
My observations are that a front wheel oscillating is essentially the same on dirt or pavement. The same basic forces are being fed into the hardware so the same basic solution should work for either. I could be wrong however it makes sense.

Dirt parking lots are probably the best doing routine slow school stuff. Hard pack dirt roads are best to get you to relax - just stay out of deep or soft stuff lest you test your crash gear. The inconsistent surface that forces the wheel right/left and slide around a bit tends to get you to relax and let the motorcycle do it's own thing instead of trying to force it into doing what you think it should do. After a few oh crapola I'm gonna die in a yard sale moments your brain gets over the initial adrenalin shock and you start being able to think about what's actually going on and start controlling it. You will find out that stiff arming the handlebars with your butt on the seat and grabbing the brakes when the wheels are wandering around on their own with a forward CG is one of the worst things you can do on a dirt road. A motorcycle moving around under you on dirt is quite safe even though your street brain says you're gonna die. It's actually safer than when it's not wandering around under you.

I've taken to doing routine slow school stuff on dirt nowadays with appropriate modifications to the maneuvers. It takes you to the next skill level. Just don't even think about doing that unless you are proficient on pavement and understand what you're getting into. You will dump yourself regularly anyway, it's just whether you fall down under control or in a bone jarring heap. ATGATT and being systematic is essential.

Little things like "do we lift our legs up? Or do we lean back? Or does a "tap" on the rear brakes help? Im just wondering of there is a set "pro maneveure" that we can all learn to get us out of it, if it strikes?

All I can say is to get proficient and stay proficient and stay under control. Then transfer those skills and proficiency level to dirt. Always, ALWAYS stay focused and don't let your brain wander off. Your first and only responsibility is to the safe operation of the motorcycle.

On dirt, especially soft surfaces where the front wheel is oscillating or the rear wheel is stepping out:
Lift your legs up? More like get your big fat lazy butt up off the seat and in the air and let the motorcycle move around under you.
Lean back? I stand on the pegs with my derrier aft somewhere over the passenger seat area.
Tap the brakes? Sure, go right ahead. I did that on soft sand a few times before I decided there were far better things to do in life - like not having to pick myself and the motorcycle up off the ground.
Relax your grip on the bars. Stiff arming it will just make things worse because in reality you're increasing the amplitude of the motion, not stopping it. By the time your brain says push the handlebar, the wheel is already starting to move back in that direction. You are 180 degrees out of phase much like stopping a dutch roll in an airplane where the real trick is to put a small quick push in the direction that the plane is rolling, not in the direction that your brain normally says to push to stop motion.

This summer I hit soft deep loose volcanic gravel at 30+mph while loaded up on a camping trip. The front wheel started going toward a tank slapper. I instantly stood up, shoved my derrier into the camping gear behind me, added a bit of throttle, relaxed my grip and let the oscillations damp out while it went back onto the slightly better harder surface. Another 2 oscillations or shoving the front wheel down with the brake in the deep stuff would have been a yard sale.

Watch videos of dirt riders doing their thing. They live in an environment where wheel wandering is normal.


Disclaimer: I'm not an expert and don't pretend to be. I just analyze what I'm doing, what's going on, apply similar situation techniques..and do a fairly decent job at keeping myself off the ground. I also have about 5,000 miles of not so polite dirt and sand experience on a street motorcycle with street tires in the last two years.

[Shmee]

Ill preface this with the note tht i have no idea what im talking about and even less personal exp with this situation. However, I just finished my training course taught by a 8time Canadian superbike champ. When the question was ask to him he said let why bike do what it wants, only work the throttle or essentially completely let go of the controls and expect/prepare for the worst.  Fighting it only makes it worse and brakes can make a simple dump and slide into a deadly high-side or endo situation.

I have zero exp with this as I'm still green but it is something that concerns me and I'll probably be back to read this thread  a couple of times in the near future.

Thanks for posting it.

[TimmyJ]

I hope you never have to go through it Shmee, it's pure hell. I think that learning how to handle it is important, but I'm thinking it might be even more important to learn how to avoid them in the first place.

I have seen many sportbike riders get into un-recoverable wobble situations. ariwhiteboy is quite right about the sportbikes power to weight ratio. Many times it was due to a sportbike rider coming down wrong from a wheelie...which he shouldnt of been doing in the first place. I dont think we Nighthawk owners have to worry much about that one lol. My 750 front will only come up a few inchs in first gear while already rolling...if I pull in the clutch, rev, and then let it out.

On the other hand some bikes have a tendency to speed wobble due to poor design. The famous Kawasaki 500 tripple is notorious for going into high speed wobbles due to it's poor frame design and suspension setup, earning it the nickname "the widowmaker". The 360 I had was a CB after all, but going into a soft shoulder like I did would of caused any bike to wobble.

EDIT: From everything I am reading, the CB750 handles well and was (is) well balenced. Im not reading anything about a balence problem with the bike, so that's good. Ok, then in the matter of AVOIDING the wobbles, I think it is safe to assume to avoid potholes, and soft spots on the road (dirt on the road for example), espicially in curves. Divits in the concrete might also be a problem, espicially in curves (where they usually exist). Loose gravel on curves can also be a problem. My theory is to ride at a reasonable speed, not too fast, so we have time to see these things ahead of time, and react accordingly.

In the matter of getting out of a wobble, I can only go by what I did which is to not touch the throttle or brakes, keep in the center (or back if possible like BB said), and let the steering do it's thing. BB mentioned it might be good to stand on the pegs if possible and that might be some good advice. I think that I did stand now that I think about it, partly because I was about to dive off, and partly because on insticnt. This is because (as BumbleBee said), the wobbles are common to dirt bikers. Before I rode on the street, I had 4 bikes I rode in the dirt more than anything. And he is correct, wobbles did happen a lot, but in dirt riding they were no big deal.

Below is an example of a wobble recovery. I'm not sure any of us are pro enough to do it like this!  



Here is another one. How the guy recovered is beyond me. I dont even know why he went into the wobble, he was on stragiht road.

[flynrider]

Here is another one. How the guy recovered is beyond me. I dont even know why he went into the wobble, he was on stragiht road.

   I've seen a lot of these on the race track.  The most likely reason for the wobble was his speed.  At 150 mph the aerodynamic forces acting on the bike cause the front end to start getting vey light.  At that point, all it takes is a small bump in the road to lift the tire clear of the pavement. When it comes back down, the chances of it being perfectly aligned are slim, and at that speed both tires had better be perfectly aligned or there's gonna be trouble.

    As for how he got out, I'd be willing to bet there was a lot of luck involved.   Basically, he kept his hands on the bar ends (without trying to correct) long enough to damp out the oscillations. Much like a mechanical steering damper is designed to do.  If you happen to be on a wide, flat, smooth piece of asphalt when it happens, there's always a chance that you'll be able to damp out the oscillations before you crash into something.  One other thing in his favor was that the oscillation didn't develop into a full tank slapper (i.e. lock to lock).  If it had, you would have heard it on the video and it likely would have had a different ending.   I've never seen anyone recover from an actual tankslapper.

[TimmyJ]

True enough, flyn.

I made this thread in the hope of all of us figuring out this very dangerous phenomonah and being able to properly handle it, and mabye save some lives. I have just run accross something on YouTube that has me thinking the answer MIGHT be at hand. This video was made in the 1980's and focuses on the wobble (which back then they called the "weave") and what to do if it occurs. There are some pretty suprising answers here: (start it at about 3:40)



Is that what we do BumbleBee? Do we "lay down"?   I never knew this...but it seems like that would be one scary position to get in if a wobble occured!

[LOKi]

so to correct the wobble you need to do a quick hand stand on the bars, then a belly tap on the tank fallowed by skiing next to the bike and it will sort itself out.

[Bumblebee]

The question is whether the wobble is a design/loading problem or whether it's rider/dirt induced like you did. It's two different things.

You went off onto a soft surface. If you lean forward onto the tank, the CG shifts forward putting more down force on the front tire. It's already oscillating due to being pushed too far down into the surface material that shoves the tire sideways to the opposite side each time and now you want to add more down force there? Not me!

My solutions:
Dirt/sand/etc: I'm going to stand up and move the CG aft. That lightens the front end so the surface material doesn't increase the amplitude of the oscillations as much. So far it works every time until the surface gets so sinky that there's no chance of recovery no matter what you do. Even a dedicated dirt bike with proper tires has it's sink limits.
Pavement: We need someone who knows the dynamics of that and preferably actual experience. I do know that if you're way forward standing up (as in able to look down over the windscreen at the front tire) with minimal weight on the rear, it can start oscillating toward a tank slapper. I for one have crashed my brains out on bicycles doing exactly that many times. On the motorcycle I simply sat down (CG move aft) to get that under control instantly. If it's doing it on it's own while seated, as long as you are able to lean forward, that might put enough down force to help damp out the oscillations. I doubt it will work at all if it's so far gone that you have to let go of the bars to lay down like in the R6 wobble video.

[LOKi]

BB don't knock that handstand on the bars trick until you have tried it. 

[Bumblebee]

BB don't knock that handstand on the bars trick until you have tried it.  

It knocked me. The last time I tried that, I ended up sliding on my nose on the 4-grit belt sander.

Your turn.  

[LOKi]

BB don't knock that handstand on the bars trick until you have tried it. 

It knocked me. The last time I tried that, I ended up sliding on my nose on the 4-grit belt sander.

Your turn. 

crap.....I'll get back to you on that.
 

[TimmyJ]

BB don't knock that handstand on the bars trick until you have tried it.  

It knocked me. The last time I tried that, I ended up sliding on my nose on the 4-grit belt sander.

Your turn.  

The key part to the "handstand on the bars trick" is skiing next to the bike (step 3). If you missed that step BB, then the trick wont work.

[Bumblebee]

The key part to the "handstand on the bars trick" is sking next to the bike (step 3). If you missed that step BB, then the trick wont work.

Oh yea, NOW you tell me.
Sounds dangerous, you go first. 

Actually I gave up skiing except for water, snow and, um, airplanes with floats or tundra tires. Other than that, forgetaboutit.

[TimmyJ]

Oh yea, NOW you tell me.
Sounds dangerous, you go first. 

I would, but...I already put my bike up for the winter 

[Grug]

Holy Hannah!  After reading and watching all this stuff about speed wobbles, I've got a knot in my face a boy-scout couldn't untie!

I noticed in one of the You Tube videos that buddy's digital speedo recorded over 100 mph at a coupla' points (I'm assuming it wasn't 100 km/h).  I will NEVER get even remotely close to that speed.  The road he (I'm assumin' it's a 'he') was on looked like some back country road...hardly suitable for excessive speeds.

[Laminar]

The speed wobble is a function of many many things:
- Steering geometry
- Suspension setup and maintenance
- Front and rear tire condition, alignment, and balance
- Luggage loading
- Rider weight and position
- Road surface
etc.

The "perfect storm" combination of any of those variable can cause a wobble. There is no one perfect way to avoid or recover from a wobble. My 550 used to wobble if I let my hands off of the bars while decelerating. I could easily pull out of it by grabbing the bars and dampening them. New tires and steering bearings fixed that issue.

I see a lot of sportbikes get the wobbles...I wonder if it has anything to do with the fact their front forks have almost no rake?

Have you observed a similar number of bikes of other styles operating in similar conditions?

I dont think we Nighthawk owners have to worry much about that one lol. My 750 front will only come up a few inchs in first gear while already rolling...if I pull in the clutch, rev, and then let it out.

The 550's short wheelbase makes it pretty wheelie-happy.

On the other hand some bikes have a tendency to speed wobble due to poor design. The famous Kawasaki 500 tripple is notorious for going into high speed wobbles due to it's poor frame design and suspension setup, earning it the nickname "the widowmaker".

Someone on the Kawasaki Triple boards posted a video of some testing done in the '70s of the triples. They found that a bike that was totally stable at 80mph with one rider would wobble violently once a rider who weighed 60 lbs less was in control, but if that lighter rider put on a 60lb weight belt, the wobble went away.