A motorcycle death wobble, also known as a tank slapper, can be a terrifying experience. Your motorcycle can suddenly be completely out of control for seemingly no reason.
We take a quick look at what causes death wobbles, what to do if it happens to you, and give you some tips on preventing them.
What is a motorcycle death wobble?
A motorcycle death wobble is when the front wheel loses stability and starts to shake from left to right uncontrollably. For the rider, the handlebars will suddenly oscillate, and you may have to let go.
During everyday riding, the rotational forces of the front wheel keep it pointing in the right direction. When a motorcycle wobble occurs, something has upset the natural balance, and we’ll look at these next.
What causes motorcycle death wobbles?
First, you can avoid motorcycle death wobbles primarily through good motorcycle maintenance and riding. That said, some circumstances may catch you out and cause you to do something that starts the wobble.
Mechanical
Poor maintenance of your motorcycle can be a contributing factor to a death wobble. As I mentioned in the basic motorcycle maintenance article, you should carry out some of these checks before every ride.
Tire pressures
Some bikes are more sensitive to tire pressures. From experience, I know my Suzuki SV1000S handling deteriorates rapidly with just a couple of psi low in the front tire.
Incorrect tire pressures, whether too high or low, can upset the balance of your bike. Hit a bump in the road at an awkward angle, and you could find yourself in a death wobble.
Tire condition
We all know the importance of checking the tread depth but also look out for uneven wear, sidewall damage or something that has gone into the tire.
Read: How long do motorcycle tires last?
Suspension
The correct suspension setup is vital. If you have tried to adjust your suspension and got in a bit of a mess, the simplest thing to do is set everything back to standard, according to your service manual.
Too hard or too soft suspension won’t react correctly to road undulations. Excessive suspension movement or lack of it can contribute to a death wobble.
Steering head bearings
Your steering head bearings take a lot of punishment. All your braking forces pass through the headstock, and if you enjoy wheelies, the landing shock also hits the steering bearings hard.
Some manufacturers are known for not putting enough grease on the headstock bearings. I’m not going to name companies, as I don’t want to be charged with libel! However, look in the relevant online groups for your particular bike to find out.
Wheel bearings
I’m betting that most riders don’t give their wheel bearings much thought, but you should.
Checking they are correctly greased will not only extend their life but could also save yours. A failing wheel bearing could quickly initiate a death wobble, and the consequences of a collapsed front wheel bearing don’t bear thinking about.
Wheels out of alignment
This usually occurs when a drive chain is poorly adjusted by relying on the adjustment marks on the swingarm. With the wheels out of alignment, your cornering is compromised, but you are also putting additional strain on your chain and sprockets.
Overloading your motorcycle
Balancing the weight distribution of your motorcycle is crucial. When it’s only you on the bike, there isn’t really a problem, but add in a pillion or luggage, and you can easily unbalance your motorcycle.
Adding a pillion, weighing 150 Ibs and then maybe 60 Ibs of luggage behind the motorcycle’s centre of balance will hugely affect the handling. When you set off, the steering may seem a little vague, but hitting a bump or uneven road surface could quickly start a death wobble.
To counter this, follow the manufacturer’s recommendations on maximum load and remember to adjust the rear suspension to allow for the extra weight.
Rider error
Even with a perfect setup and a well-serviced bike, it’s always possible for a rider to induce a death wobble through poor riding skills.
One of the most common causes is wheelies. The wheelie won’t cause a death wobble, but how you bring the front wheel down can. Land the front wheel only slightly out of straight, and the auto-correction when the wheel hits can set off a wobble.
Poor rider control can also contribute to a death wobble. Holding the controls too tightly, aggressive movements and cornering, pulling wheelies, and ignoring road conditions all affect your motorcycle’s handling.
I’m a firm believer in continuous rider training and the development of skills. Every day is a learning day!
Road surface
Our bikes can usually cope well with different road surfaces, but add in any of the factors discussed above, and the combination can send you into a death wobble.
It’s usually the sudden change in the surface that causes the problem, such as hitting painted white lines while cornering. Or maybe there is a groove in the road surface that suddenly changes your front wheel’s direction.
Constantly checking the road surface and good training will help you avoid these situations.
Airflow
Many of us like to tour on our motorcycles, which generally means carrying luggage. If you are the type of person that takes everything, including the kitchen sink, then you might end up with a skyscraper on the back of your bike.
Not only is this bad for the balance of your motorcycle, but you’ll also upset the airflow over your bike. All that weight and a messy airflow is a recipe for a death wobble, mainly as you’ve made the front-end light.
How to control a motorcycle death wobble
Don’t panic! If you panic, you will likely grab the handlebars and hit the brakes. Both these could make things worse and make the wobble terminal. Try to keep a light grip on the bars, and don’t try to fight the wobble.
Each motorcycle’s handling and reaction to a death wobble is different, so although there’s not one guaranteed solution, there are things you can try.
Throttle
Either gently accelerating or slowly rolling off the throttle can stop the wobble. Only by trying both will you find which works. The thing to bear in mind is that your movements need to be smooth and gentle.
Brakes
Applying a little back brake may calm the wobble. Doing this allows the front wheel to auto-correct itself while adding a little weight to the front wheel.
Using the front brake is not usually a good idea, partly because you can’t control the pressure while the bars are flapping around. You may also put too much weight on the front wheel.
Engine braking
Gently rolling off the throttle induces engine braking, puts a little extra weight on the front wheel, helping it auto-correct, and slows you down gently.
Preventing motorcycle death wobbles
Regular maintenance
Many causes of death wobbles can be linked to poor maintenance, although not all. Maintaining your bike and following the manufacturer’s guidelines will make a huge difference.
Regular maintenance has many other advantages, such as holding the value of your motorcycle. If something goes wrong out on the road, being familiar with your bike means you may be able to fix the problem yourself.
Fit a steering damper
Some motorcycles, rightly or wrongly, gained a reputation for being a little unstable. I’m thinking particularly of the Suzuki TL1000S. One of the fixes was to fit an uprated steering damper, although many blamed the unconventional rear suspension unit used by Suzuki.
If your motorcycle doesn’t have a steering damper, it may be a good idea to fit one. Even if your bike has one, an upgrade may improve your handling, as some factory-fitted items are not great.
Learn to wheelie properly
Some people enjoy pulling wheelies. I get it.
In my youth’s dim and distant days, I owned an RD500LC fitted with Padgett racing pipes. When you hit the powerband in the first three gears, it lifted the front wheel unless you worked hard to stop it. I wasn’t very good at wheelies; it has to be said!
Many people offer safe wheelie training, where you can practice in a controlled environment. I’d highly recommend this if you like to wheelie.
Last but not least
Death wobbles are not that common. Your motorcycle naturally wants to go in a straight line. However, should you get one, it can be terrifying.
We can do many things to limit the chances of getting into a death wobble, but knowing how to control one will always be helpful.