Motorcycle Speed Wobble Solved

Death wobble. Tank slapper. Speed wobble. Whatever you want to call it, it is an unfortunate event to experience on a motorcycle. If you have ever experienced the phenomenon of having your bike try to shake you loose like a bucking bull, then you know exactly what I’m talking about when I say death wobble.

If you have not yet experienced a full-fledged tank slapper, then let’s get you up to speed before one sneaks up on you. I encourage you to take a moment and watch the video below to see a quality example of such an event.

There are certain circumstances that can create an excessive wobble like this from the front end of your motorcycle while riding. This is an extremely dangerous situation that if not handled properly could lead to a crash.

The purpose of this article is to determine the causes of a high-speed wobble and how to solve this problem. I myself have experienced several death wobbles and would like to provide some useful information to help keep other riders safe.

In general, high-speed front end motorcycle wobble can be prevented by using a steering stabilizer. If you don’t have a stabilizer installed, the best practice is to slowly roll out of the throttle without using the brakes and keep your grip on the handlebars very light. Do not try to fight the wobble or make any abrupt movements.

What Causes Front End Wobble On A Motorcycle?

In most instances, speed wobble occurs at higher speeds on sport-oriented street bikes.

In general, sportbikes tend to accelerate at a higher rate and can achieve higher top speeds which can induce instability in the front end. Additionally, the steering rake on a sportbike is typically steeper which also increases the instability in the front end.

The rake angle of a motorcycle is the interior angle created by the front forks and a vertical line drawn from the front axle.

On a sportbike, this angle is very steep or sharp to allow for the bike to turn into a corner more aggressively. The compromise is that this reduces front-end stability under heavy acceleration or braking.

The rake angle on a sportbike like the Ducati 899 shown above is 24 degrees. Compare that to a new Honda Goldwing which is 30.5 degrees. This style of bike is a cruiser that caters to a more stable and controlled riding style. Most Goldwing riders aren’t going to be cornering aggressively or optimizing for the ability to turn in sharply.

Other causes of speed wobble include excessive gusts of wind and uneven road conditions.

Sometimes outside factors out of your control can be the cause of a death wobble. This is where it becomes important to hone your skills as a rider and be prepared for any situation that might present itself.

If a heavy crosswind hits you, especially at freeway speeds, it can either disrupt the front end of your motorcycle or cause you to attempt to overcorrect and induce the wobble yourself.

Another factor is the road condition. Depending on the quality of the road and if there are any ruts dug into the asphalt if your front wheel becomes destabilized this can cause a wobble as well.

It is critical as a rider to be aware of what kind of surface you are riding on. Notice any grooves that have been dug into the road by heavy vehicles. Also be aware of damage of potholes that if hit could unsettle your front wheel. Some roads have patchwork like the one pictured to the right which can present some challenges to an entry-level rider.

It is also worth noting that on a sportbike the front tire is typically thinner and taller than a cruiser bike.

Most commonly you will see a 120/70R17 size front tire on something like the 899 Panigale. The first number is the width of the tire in millimeters, the second number is the aspect ratio which represents the height of the sidewall, and the third number is the rim size.

In order to create more stability with a heavier bike or one designed with comfort in mind, the front tire will typically be wider and shorter. This creates a larger contact patch of rubber touching the ground at any given time.

How To Prevent Motorcycle Wobble

Now that we have an idea as to what we’re going up against, let’s put together a game plan to avoid this from happening altogether.

There are a few tactics and tools we can implement to avoid a speed wobble from ever occurring.

  1. Steering Stabilizer: Installing a steering stabilizer is typically the first modification I make to any sportbike I own. It is an easy job to do yourself and provides such a radical Improvement to the front-end stability of the bike. The stabilizer attaches to two points: the frame and the steering head. These two mounting points both attach to the steering stabilizer itself which is a little mechanism filled with hydraulic fluid to allow for dampening sort of like how your forks work. I would personally recommend the GPR Stabilizer as I have used it on many bikes with great success. It is adjustable so you can have a lot or little dampening depending on your experience level and riding style.
  2. Proper Maintenance: Performing correct routine maintenance is critical to avoiding speed wobble. Firstly, make sure your tires are not over or under inflated. Especially over inflated tires can reduce the stability of your frontend more than usual and is a very simple problem to solve with a routine inspection. Additionally, make sure your steering head is properly torqued and lubricated. The triple clamp is secured to the bike with a nut that needs to be torqued to a specific specification.
  3. Proper Bike Setup: The next thing I would look into is to make sure your suspension is setup correctly. Your weight is the main metric used to set the forks and rear shock. If this hasn’t been touched from factory settings, most people will be ok just leaving it alone. However, if you are a smaller rider and purchased the bike used from a big dude, the forks and shock might be way too stiff for you and can also cause instability. My recommendation would be to take your bike to a shop that has a technician that knows how to set ride height, preload, and dampening correctly.
  4. Improve Your Skills: The last preventative measure I’ll mention is to work on your skills as a rider. Excessive head shake can be prevented by riding correctly and knowing what to feel for. Overtime, as you get more seat time, you will be able to feel a death wobble coming before it happens. This is also why it is critical to keep a light grip on the bars. You don’t want to white knuckle the grips as this will reduce your ability to feel the bike and anticipate what will happen next. I suggest a high-level rider course or even some track time to gain skill and experience.

GPR Steering Stabilizer. The little peg at the bottom slots into a bracket mounted to the frame. The big assembly mounts to the triple clamp. You can adjust how heavy the damping is from 0 – 20. Make sure to pick the right model for your bike as all mounts don’t match up the same way.

How To Correct A Front End Wobble At High Speed

If you’ve done everything within your power and find yourself at the beginning stages of a tank slapper, then there are some key bullet points to keep in mind as your life flashes before your eyes.

  • Make slow controlled inputs

Your first response is probably going to be panic and hold on for dear life. I encourage you to train yourself to hold the grips like loaves of bread and calmly roll off the throttle. You want to let the bike settle itself down. There’s no wrestling this thing into submission once the bars start slamming back and forth.

  • Do not touch the brakes

If you even think about touching the brakes during the excessive head shake, the front end will tuck and you will be on the ground before you know it. The idea here is to gradually slow down and continue moving not come to a complete stop.

These two thoughts will serve most riders best if you find yourself in this unfortunate set of circumstances. In the split second you have to make a good decision, you don’t want more than a couple thing to think about. As you grow in experience, there are some other tactics you will pick up on that best suit your style.

If you find yourself on a powerful enough bike and catch the wobble early enough, you can power out of a death wobble if you grab enough throttle. I’ve personally had success with this on a liter bike with the rpm’s built up high enough in the power band.

There is some risk in this if you don’t have enough power accessible which is why my initial recommendation for most folks is to roll out and let the bike settle.

Watch this video with caution. Some of these guys ran out of talent and weren’t able to keep the rubber side down during their tank slappers.

Can A Motorcycle Wobble At Low Speed?

It’s worth discussing other situations in which a wobble can occur. In contrast to high speed, a motorcycle can exhibit unstable behavior at low speed too.

This is typically going to result from mechanical failure of some kind causing more of a low-frequency wobble rather than what has been discussed thus far.

Some failures that may lead to this situation include:

  • Tires out of balance
  • Loose axle nut
  • Excessively worn suspension
  • Bent rim

It is vital to perform pre-ride inspections because most of these issues can be spotted with a simple visual inspection.

This is a much less common type of wobble and is something that develops over time, so be aware when riding of anything that feels off or not quite right.

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