What Causes Motorcycle Death Wobble (How To Prevent!)

I have been riding for over 20 years now. Out of the top 3 scariest experiences in two decades, the death wobble has to be in the top 3.

I luckily did not go down. But the experience was chilling and left mental scars even when it did not leave physical.

Let’s understand what causes the death wobble on a motorcycle it and what you can do about it.

A death wobble in a motorcycle occurs when the front wheel loses its ability to maintain a straight line of motion. This loss of capacity is caused by aggressive acceleration, wheeling, worn-out steering head bearings, worn-out front tire bearings, uneven tire wear, incorrect tire pressure, tire misalignment, bold gear changes, or incorrectly tuned suspension.

Whatever the cause, a death wobble occurs when the front tire cannot maintain a straight line motion.

The front tire will immediately try to correct its line of motion if deflected to the right or the left. But if it overcorrects, then we end up with an oscillating movement of the front tire — a death wobble, essentially.

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What is a death wobble?

A death wobble is the violent and uncontrollable shaking of the front tire in an oscillating motion from side to side. As a result, the motorcycle handlebars also shake uncontrollably, making the motorcycle very unstable.

A death wobble at high speeds usually leads to a crash.

A death wobble is also called a tank slapper, a high-speed wobble, a shimmy, and a head shake.

Here is a video showing you just that:

Underlying issues that make your bike a death wobble motorcycle

1. Sudden aggressive acceleration

When you accelerate aggressively, there is suddenly an increase in the weight on the rear tire. The front tire loses carries less of the weight, and the rear wheel gains it. This can cause the front tire to lose traction and deviate from the straight-line motion.

At this point, you have in your hands essentially a death wobble bike. There is a very high for the bike to now wobble, because the front tire might overcompensate motion correction under reduced traction.

2. Wheelies

I love wheelies. That I can’t do a proper one, even with 20 years of riding under my belt, is a shame.

When you pop a wheelie, the front tire is off the ground. When you drop the front tire back to the ground, it may not be pointed straight.

And that sets you up for potential motorcycle wobbles.

At higher speeds, dropping the front when not pointed straight will almost certainly lead to a tank slapper.

At lower speeds, with the front tire pointed straight, gently bring the bike down.
And you should be OK!

3. Worn out steering-head bearings or wheel bearings

Bearings in a motorcycle ensure that there is very little friction and no play between parts.

Worn-out bearings introduce play between the parts that they connect. This can be catastrophic for precision equipment and heavy machinery in particular.

In the steering head and the wheels of a motorcycle, worn-out bearings can offset the wheels from their default straight-line motion. As a result, the front tire movement may be compromised.

You’ll notice this immediately because the front tire and handle bar movements will have play. You may also notice the bike will have a tendency to deviate from a straight line motion.

Important note: Have your bike checked out immediately in this case, by a trained mechanic!

4. Uneven tire wear

Your tires may wear out in a way that prevents the motorcycle from maintaining a straight line of motion.

That’s a problem.

This lateral tire movement will require you to constantly compensate to make the motorcycle go straight. This will not only compromise straight-line motion but make cornering risky!

If you ride with such worn out tires for an extended period, a high-speed wobble is inevitable.

Important note: Get the tires examined by a mechanic immediately.

5. Incorrect tire pressure

This has more to do with low pressure than high.

Low pressure on your tires, especially the front, will cause the tire to have lateral movement. Couple this with high speed, and you have a setup for a motorcycle wobble.

A worst-case scenario would be to suddenly lose pressure at high speeds, such as from a flat tire!

That would surely be disastrous.

Always physically examine the tires before you ride. You need less than a minute!
Know the correct tire pressure for your bike. Check the shop manual or ask a knowledgeable riding buddy!

6. Tire misalignment

If the tires on your motorcycle are not correctly aligned, your bike will forcibly turn to either right or left on its own.

It will not want to go straight.

As a result, you will constantly be correcting the handlebar.

You would have the handlebars turned slightly right or left to keep going straight!

At high speeds, constant corrections to the handlebar would increase the chances of triggering a speed wobble immensely.

Important note: Tire misalignment is a serious issue, and you need to have your motorcycle checked immediately.

7. Aggressive gear changes

When you blip the throttle shifting down or when you chop it going up, you might accidentally add some counter steering.

On the track or otherwise, when riding aggressively, this scenario can go down.

The push or pull on the handlebar on the right side (throttle side) to modulate the throttle can unexpectedly trigger counter steering. At high speeds, an unexpected counter steering push may lead to a death wobble.

8. Incorrectly tuned suspension or uneven weight distribution

If the front forks unequally compress or rebound, the motorcycle will tend to turn sideways than go straight.

The tire wear will bear telltale signs of this.

This will bring us back to the classic situation where you are at war with your handlebars to keep the bike straight.

Add high speed to the mix, and we have set ourselves up for a death wobble!

Uneven weight distribution across the front (light) and rear (heavy), makes the front lose traction over bumps quickly.

The rear suspension is compressed more than necessary. The front suspension has much less load on it than needed.

Such a bike tends to have reduced traction in the front wheel and is at greater risk of a death wobble.

9. Dynamic Engine Mounting (Engine shifts weight)

Suppose your type of motorcycle is a cruiser from Harley-Davidson motorcycles. In that case, you already know what I am going to say.

Harley riders know all too well about the famous Harley death wobble. The Dyna Harley made it famous, though.

The Dyna powertrain can move within the frame since it is rubber mounted. This would cause the entire bike to shake and wobble because of the shift of weight of the engine.

While cornering, the Dyna has a high tendency to get into a death wobble.

If you own a Dyna, you can now get this fixed.

Check with your mechanic on how this can be done.

What to do if you are in death wobble?

Here’s what to do if you find yourself in a death wobble:

1. First thing: don’t panic; you got this!
2. Don’t hit the front brake at all.
3. The best way to work the throttle is to roll off the throttle slowly. Don’t chop or blip.
4. Don’t change gears immediately.
5. Don’t try to take control of the bike with aggressive movements. You have to ease into controlling the shake. Keep the grip loose, but don’t let go of the grips.

As you roll off the throttle slowly, the bike will slow down, and eventually, the death wobble will stop.

Check out this video where the rider does very well to get things under control. He doesn’t slow down the bike with braking. As the bike slows down, he regains control.

It is super scary, nonetheless!

Some motorcycles have steering dampeners. They help prevent a death wobble.
Check if your bike can be fitted with one.

Here is a picture of the steering dampener on my Kawasaki ZX-10R.

Conclusion:

Hand’s down a death wobble is what all bikers dread.

I experienced it when I accidentally launched myself off a ramp on the road on my Kawasaki Z900 at about 70mph.
That is certainly what causes speed wobble on a motorcycle, as do all these other 8 reasons:

• Wheelies
• Worn out steering-head bearings or wheel bearings
• Uneven tire wear
• Incorrect tire pressure
• Tire misalignment
• Aggressive gear changes
• Incorrectly tuned suspension or uneven weight distribution
• Dynamic Engine Mounting (Engine shifts weight)
  

I was in the air for about a second or two (it felt like an eternity). The front tire was not pointed straight when I landed.

That immediately led to a death wobble.

For one, the sudden, unprepared air-born experience had me by surprise. And when I landed, the death wobble made it a living nightmare.

But it was all over in under 5 seconds.

Thankfully, I did not go down. There was no incoming traffic. And I lived to tell the tale unscathed physically.

Yes, It was my fault – rider error. I should have been more focused on the road.

But we live and learn!
Ride safe, my brothers and sisters! ✌️