What Causes Motorcycle Death Wobble? Preventing Tank Slappers

What causes death wobble and how do you recover from it? It’s scary as hell when it happens to you and more often than not results in a crash unless your prepared.

What Causes Motorcycle Death Wobble?

The death wobble is a shimmying, shaking or oscillation that occurs when a mechanical or rider induced irregularity occurs with the front tire or steering component(s) of the motorcycle. This causes the front of the motorcycle to shake from side to side violently.

Speed and other physical forces can wind up being too much for your bike to handle. For many riders it happens when corning due to stress being placed on the forks and/or chasis.

Cornering is only one of the ways you can wind up dealing with motorcycle front end wobble when you’re out on the road.

Then there’s rear end wobble – With a rear end wobble, the bike will fishtail and yaw repeatedly leaving you with a feeling of no longer being in control of your ride.

How do Front End Wobbles Start?

Let’s get back to the basics;

Motorcycles have two sections, a front and the rear.

A wobble or oscillation occurs with the front components of the motorcycle. Fishtailing or weaving occurs with the rear section.

The process is repeated when opposite force is applied (either by the bike itself or externally) and the whole thing starts over again but compounds to make it worse. This is what causes the oscillation or speed wobble. You can check out more here.

This opposite force can be applied from the rider or just the friction of the roadway.

Once the wobble starts, the force or process gets worse and worse usually to the point where the rider can’t maintain control anymore. Then of course, the result is a crash.

Rear wheel speed wobbles can be easier to deal with, but front end wobbles can cause a motorcycle to crash in no time flat if they get out of control.

Rear Wheel Wobbles

Here’s the thing-

Rear wheel wobbles can be easier to deal with (but no less dangerous or frightening), and a lot of times can go unnoticed if you’re riding a larger heavier bike.

If your traveling at a lower speed with a heavier fully loaded motorcycle you may not notice it much at first (however the traffic behind you will) which can make the wobble a bit harder to detect.

That being said, with touring motorcycles a heavier load not distributed across the bike properly can contribute to a rear wheel wobble. The load is not centered on the bike and unevenly distributed.

Most riders (and passengers) know how the bike is supposed to feel and therefore will pick up on the wobble right away.

I mentioned having a passenger so you should also know – If you ride with the same passenger (for me it’s my wife) they also know how the bike should feel. Don’t discount their knowledge.

Being familiar with how your motorcycle handles both when its empty and loaded will alert you to problems so that you can pull over and get them taken care of before they’re out of control.

Motorcycle Wobble Causes:

Speed. In some makes and models motorcycles, once the bike attains a certain speed, it can go into a wobble because it can’t handle it.

With any bike, excess speed (specially when cornering) puts extra stress on parts and can cause the bike to start wobbling.

Swingarm having too much play or movement. From my reading, This seems to be an issue mostly with sport bike suspensions, not as much for touring bikes. An eighth of an inch (for example) doesn’t seem like much play, but apply physical forces to it and you’ve got a problem.

Wheel bearings becoming too worn. This results in lateral movement (see below).

Lateral movement on axle. The front or rear wheel has too much lateral or side to side movement on its axle. This can be from wheel bearings or other problems.

If you have lateral movement in your wheels you need to STOP riding and get the bike to the shop.

Tires. When it comes to tires any one or combination of the following can contribute to motorcycle speed wobble.

• Flat spots- tires that have flat spots coupled with an irregular roadway surface can increase how susceptible you can be to having an incident.
• Wheel balance- Tires look ok but you experienced a ‘random’ speed wobble? You may want to have your tires balanced.
• Low Tire Pressure- Make sure your sticking to the motorcycle tire pressure recommendations and checks for both the tire and motorcycle manufacturer.
• Are they new tires? Make sure you check out or article on how to break in new motorcycle tires.

Make sure you inspect your tires before every ride!

Improper weight distribution. As mentioned previously, you and your gear may not be loaded properly on the motorcycle.

Rider Error.  Did you take a corner too fast and leave the roadway onto the dirt shoulder, or some other screw you did?

Trying to power your bike through loose road material at a highway speed is potentially introduce you to the world of the speed wobble.

This is what happened to me.

What about Harley Davidson?

There seems to be some discussion that certain models of Harleys can be prone to suffering from high speed wobbles. The Road King and Ultra Classic are just two bikes that have been singled out as being problem children with many a lawsuit being filed. You can check out this story about one such harley owner and his wobble accident.

The now infamous Harley speed wobble video

Recovering From a Motorcycle Wobble

There are a lot of varied opinions on how to recover from a speed wobble. What I’ve listed below is what worked for me.

Each rider (myself included) can tell you what they did to recover, but the reality is you’re just not going to know exactly what to do until you get there. The best you can do is have a basic strategy based on what read here and other motorcycle blogs.

Pro motorcycle racers know techniques to to accelerate through wobbles which I would not recommend for us ‘normies’ (normal riders) unless you really know what your doing.

Recovering a motorcycle speed wobble is actually simple, but it requires that you don’t panic and keep your wits about you.

Front end speed wobble recovery:

• Keep a firm grip on the handlebars.
• Roll off the the throttle with control (no sudden moves)
• Lean forward into the handlebars or pull the handlebars to you. It has the same effect of helping you maintain control.
• Allow the motorcycle to decelerate naturally without downshifting or applying the brake.
• DO NOT put your feet down.

Steering Dampers

For some motorcycles you might consider installing a steering damper to help limit that helps to act as a sort of ‘shock absorber’ while your steering.

Steering Dampers are widely available for sport bikes but not so much for the larger touring bikes.

My Experience With a Wobble

I’ll simply start off by saying, that my speed wobble incident was a 100% my own fault, and I was very lucky that I didn’t injure myself or my passenger.

It was scary, surreal and violent.

I was able to maintain control of my motorcycle and bring it to a stop using what I just outlined above.

I did learn a valuable lesson.

Read on…

Heading Out For Our Ride

A few years ago, myself, my wife and a good riding buddy of mine decided to do a west coast ride down pacific coast highway. The ride happened to coincide with my youngest daughters move to the Seattle, Washington area.

Perfect! Truck the bikes up, drop off my daughter’s stuff and ride PCH back. Which was exactly what we did.

We packed up our gear, did a quick cleaning job after having to store the motorcycles outside without a garage and then hit the road.

We left early on a Sunday morning (by the way, the best day of the week to get through the Seattle area because of traffic) and headed south through the state of Washington.

The original plan was to get a room in Seaside, Oregon.

Our route took us from Seattle through Olympia towards the western Washington coastal area of Aberdeen/Montesano and ultimately south towards the Columbia river area.

After crossing the Columbia river at the Megler Bridge in Astoria, we took a break to check our hotel plans.

Because we were in peak travel in season in June, we soon discovered that there were no hotels in Seaside or Astoria (hotels tonight you failed!).

We found that the only hotel(s) available were in Longview Oregon. We headed east out of Astoria, Oregon on highway 30.

Get Ready For The Pain!

Highway 30 east out of Astoria follows the southern bank of the Columbia river and of course gets very twisty in places.

Having just completed a turn that required a nice right side lean, I saw the next sharp turn coming up that would require that I lean left.

All fine and dandy except…

I misjudged how sharp turn was (it cut back onto itself hard), and I was going a little too fast.

As I was into the turn, I realized that I wasn’t going to make the corner, and there was a guard rail (thankfully). It’s a crappy and surreal feeling knowing that you can’t make the turn and you may crash with a passenger on board!

After exiting the south roadway edge, I managed to thread my motorcycle between the edge of the road and the guardrail.

Which was fine and dandy except there is no pavement, only soft dirt or pavement material that’s often found on the shoulders of a highway.

Controlling The Beast

Hitting the soft dirt/material caused the handlebars to slap back and forth violently. I was happy that the bike was starting to come to a stop, but the slower the bike went the worse it became (contrary to some stories I hear) threatening to rip my arms off.

The whole front end of the bike shook violently, and somehow I was still hanging on through all of that!

I was lucky coming out of that incident that my passenger and bike wasn’t hurt. I rolled my ankle in the incident but wasn’t hurt bad enough to not be able to walk thankfully.

My pride also suffered a severe blow as well!

There were multiple lessons learned, but I won’t forget how violently the bike shook. I also had to take a few moments to rest – its the one of those times where riding a motorcycle will make you tired.

A Hard Lesson Learned

All in all, it was my own fault – I misjudged the turn was going too fast into the turn (only about 5 – 10 mph over. It doesn’t take much!) and left the roadway. Hitting the soft shoulder material caused the front started the process that got much worse before it was better.

I was lucky to be able to keep everything under control. Speed wobble usually doesn’t end well.

Summing it up…

As you can see, what causes motorcycle death wobble generally boils down to either rider error or a mechanical issue with your motorcycle.

This thing is, is that both are under your control. You can always work on your riding skills and you can make sure that you keep your bike serviced.

I have a thorough safety inspection done at every oil change and have my mechanic walk me through what he looked at and explain things to me.

This does two things:

• Shows me what he checked
• Helps me to learn more about my motorcycle

I’m no mechanic so it helps me to learn more about my motorcycle and have a clue what’s going on with it.

Now you know what causes death wobble and how you can recover from it. It’s scary and dangerous and can cause an accident if your not ready for it.

Make sure you monitor your motorcycles mechanical condition.

Oh ya – Keeping the motorcycle on the road helps to!