Why Do Motorcycle Handlebars Shake? (Speed Wobbles)

Motorcycle Acceleration

When driving at high speed, sometimes, the motorcycle handlebar starts to shake violently. These are called speed wobbles or tank slappers.

So, why do motorcycle handlebars shake? The reasons why motorcycle handlebars shake are – wheel misalignment in the motorcycle, flat tire or low pressure in the tire, uneven loading, accelerating at a very fast rate, and suspension and bearing problems.

When faced with a motorcycle handlebar shaking, you need to – have a loose grip on handle bar, then slowly roll off the throttle and decelerate, apply the rear brake while slowing down and try to lean forward.

However, do not grip the bar tightly, pull in the clutch, use the front brake, accelerate the throttle, or lean back.

Once the handlebar shaking is stopped and the motorcycle is under control, take the bike to the mechanic for servicing and check the components.

Reasons For Handlebar Shaking

There are many reasons why the motorcycle handlebar shakes when driving at a high speed. The main reasons include – wheel misalignment in the motorcycle, flat tire or low pressure in the tire, uneven loading, accelerating at a very fast rate, and suspension and bearing problems.

Let us deep dive into each of these causes for motorcycle handlebar shaking.

First, when the motorcycle is accelerated at a very fast rate during high speed, the handlebar can start shaking. When you are running your motorcycle at a high speed and on top of that, you start accelerating at a very fast rate, there is a possibility that your front tire might lose some traction due to the sudden acceleration.

You may have experienced this before whenever you accelerate rapidly from rest, the motorcycle jumps slightly forward. This is again because the front tire loses traction because of the sudden acceleration you have produced.

The same phenomenon happens but at a dangerous level during high speeds, resulting in the handlebar shaking and in the worst case, the rider will lose control for the handlebar completely.

Second, the misalignment of the two wheels can also cause the motorcycle handlebar to shake. When the front and rear wheels have more than required room for lateral movements, the motorcycle will start wobbling. The wobble might not be pronounced at low speeds, but once you speed up, it gets noticeable with increased oscillation of the handle bar.

The misalignment between the front and rear wheels can be caused because of a part malfunctioning, worn-out components or alignment was not proper during your last servicing of the motorcycle.

Third, another reason for handlebar shaking in a bike at high speed is a flat tire or low PSI in one or both of the tires.

Flat tires are much easier to identify if you have been riding motorcycles for long. Even at low speeds, you will know something is not right in the wheels. For low pressure, you must regularly check your wheels. A large difference from the actual to the required PSI will always create problems in some or the other ways.

Fourth, an uneven loading on the motorcycle will also cause the handlebar to shake violently while riding at high speeds. If there is a heavy loading on the rear part of the motorcycle sufficient enough to create a large differential.

The uneven loading coupled with the high speed in your motorcycle might induce the front tire to lose traction from the ground surface. As a result, you could be facing the handle bar oscillating rapidly.

Lastly, the speed wobbling or the handlebar shaking can also be caused by problems in the bearings or suspension. Worn-out bearings specially on the front side can be quite dangerous which might result in death wobbles.

Speed Wobbles

Motorcycle speed wobbles, also called tank slappers or death wobbles, are why the handlebar shakes in the motorcycle. This shaking is caused at high speeds when the front tire loses traction and your handle bars start oscillate violently.

Motorcycles naturally wiggle. The traction between the tire and the road always produces vibrations in the motorcycle. So, there is always some wiggle in the system.

However, the problem starts when the wiggle goes out of hand. The handle bar starts to shake rapidly and you have no control over the oscillation.

The wobbling usually happens at high speeds north of 70 mph. It is very unlikely that you will face speed wobbles while riding at low speeds.

Speed wobbling can be extremely dangerous because of the fact that you are riding at a high speed, and it can end up in hazardous accidents.

Things To Do When Handlebar Shakes

When you are faced with the motorcycle handlebar shaking, you need to – i) have a loose grip on the handle bar; ii) slowly roll off the throttle and decelerate; iii) apply the rear brake if slowing down; iv) lean forward if possible.

Firstly, have a loose grip on the handlebar. You might intuitively feel like holding the handle bar tightly in order to stop the wobble.

However, do not hold the handlebar. It would do more harm than good

Instead, you should loosen your grip to not cause any further disturbance to the motorcycle. Loosening the grip will also allow the motorcycle to self-correct and slow down the oscillation.

Second, slowly roll off the throttle and decelerate. Decelerate and slow down the speed of your motorcycle by slowly rolling off the throttle.

Do not pull in the clutch or apply front brakes in a hurry to stop the motorcycle.

Third, apply the rear brake while slowing down. Once you have started decelerating the motorcycle by slowly rolling off the throttle, start applying the rear brake.

Applying rear brake slows down the bike further in an organic way instead of any sudden brakes. This is helpful in two ways – motorcycle slowing down to low speed can stop the handlebar shaking and also, the reduced speed will help you to gain more control of the handle bar.

Lastly, try to lean forward, if possible. This is helpful specially when the shaking is because of uneven loading in the front and rear end of the motorcycle. The low weight in the front end might have caused the front wheel to lose traction. As a result, leaning forward will be helpful to re-balance the load slightly.

Things To Avoid When Handlebar Shakes

Now that we have discussed what should be done when faced with the motorcycle handle bar shaking, we should also know what things should not be done.

First, you should not grip the handle bar tightly. This might seem counter intuitive, however gripping the bar tight will do more harm than good. So, do not tighten your grip on the handle bar.

Second, do not pull in the clutch, use front brakes or accelerate the throttle. All these things will not slow down the shaking, rather they might cause the bike to fall down. So, do not try to use clutch, front brake or accelerate the throttle.

Lastly, do not lean back when your motorcycle handlebar is shaking. If the shaking and wobbling is because of uneven loading, then leaning back will actually increase the shaking and wobbling.

Visit The Mechanic

Once the handlebar shaking is died down in your motorcycle, do not leave the matter labeling it as one off incident.

As soon as you have recovered from the handlebar shaking, take the motorcycle to your mechanic at the earliest. There is a high chance that you might again face this situation if you speed up higher. And you should definitely not risk that.

Also, for the prevention of handlebar shaking, you need to do regular motorcycle servicing and maintenance. Take your bike for servicing frequently. Check the components and their working condition from time to time.

Related Questions

What causes excess engine vibration in motorcycles? Excessive motorcycle engine vibration is caused by loosened engine mount bolts, out of sync carburetor, out of tune engine, or cracked frame or suspension components.

How to deal with speed wobbles? When faced with a motorcycle speed wobble, you need to – i) have a loose grip on handle bar; ii) slowly roll off the throttle and decelerate; iii) apply the rear brake if slowing down; iv) lean forward if possible.