Have you ever experienced a speed wobble or also referred to as the death wobble? It can be a terrifying experience. This week will talk about the common causes and how to handle a death wobble if it happens to you.
A motorcycle is most stable traveling on a level surface, at a constant speed in a straight line. In fact, if you let go of the handlebars a motorcycle will continue to travel in a straight line unless some other force interrupts that. A motorcycle is engineered to stay upright at speed our job is not balance the bike but to provide direction.
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My experience with wobble
Years ago I had a Yamaha FJR and I was in the market for a new set of tires. I went to a local shop that I trusted and purchased a new set of Shinko tires for the FJR. This was my first experience with Shinko and I was trying to save a few bucks. On the ride home I was decelerating from highway speed down to a slower speed. When I hit 40 MPH down to about 35 MPH the handlebars would shimmy back and forth. I actually have a video I did for RiderGroups.com that demonstrated the shimmy I was getting from the motorcycle.
In this case, it was a defective tire and in fact, 3 different tires from Shinko all proved to be defective and caused this shimmy on the FJR. So at least during that run of tires, Shinko was having some issues on the production line. The shop worked with me and we eventually put some Micheline tires on the FJR and the problem was completely solved.
But there can be all kinds of reasons other than defective tires that cause this type of reaction from the motorcycle.
We will break this into 2 types of issues, mechanical and road surface.
Mechanical Reasons for a Death Wobble
Improper Tire Pressure
This can’t be stated enough…you have to maintain the tire pressure on your motorcycle at the recommended spec. Not only will you get more life from the tire but they will also handle like they were designed to.
Worn Tires
If tires are worn from use and in particular if they are run frequently at the incorrect tire pressure you can develop a tire that wears unevenly and this has an effect on the handling of the motorcycle.
Other Mechanical Issues
Might be an improperly loaded motorcycle, loose spokes, a dented rim, maybe the rear tire is not in alignment with the front, worn bearings, there are a whole host of mechanical issues that could be the cause.
If you experience a wobble in the front of the motorcycle and the road surface is not to blame, you need to diagnose the problem or have the motorcycle checked by a qualified mechanic. It is not something that will fix itself…and it needs to be addressed.
Road Surface as Cause for Death Wobble
In addition to mechanical issues, the road can also cause feedback up through the handlebars.
This is probably the one that most riders have experienced. Grooved roads from construction or bridges that have a grated surface, gravel or small slick patches on the road can cause the handlebars to either suddenly or with some consistency depending on the surface to shimmy back and forth.
The feedback that you get through the handlebars due to the road surface is usually not a big deal. We make worse by our reaction to it.
So here are the things that you don’t want to do:
- Tighten up on the handlebars
- Look down at the surface – remember to keep your head and eyes up.
Here are the things you want to do:
- Let the motorcycle move and find it’s path – remember, you are not what is keeping the motorcycle upright. The motorcycle will correct itself if you don’t do something to mess it up
- Stay loose and look where you want to go
If you ride with a loose posture, some flex in your arms and maintaining a relaxed upper body the motorcycle will correct itself over small issues with the road. So stay loose and if you feel like you need to hold onto the motorcycle, use your legs to do so by squeezing on the tank but keep your upper body loose.
Some riders feel that a motorcycle is inherently unstable and it is the rider’s responsibility to provide balance when in reality we are often the problem with the motorcycle’s ability to stay upright. It will correct itself over minor road inconsistencies as long as we don’t interfere and keep it from doing its job.
When it comes to mechanical issues causing shake or vibration it can get a little more complicated.
In those situations, you want to maintain your grip on the handlebars while gently rolling off the throttle. If it is a violent shake you are not going to be able to overcome it with shear strength. Don’t grab the front brake, you can gently use the rear brake to help scrub off some speed. As speed decreases slowly the shimmy will likely go away. It may help to lean forward over the tank as well to help the motorcycle get out of the wobble or shimmy.
Once you have the motorcycle under control the next thing you want to do is find out what caused the problem and fix it. If a motorcycle gets itself in a death wobble or violent shake it is important to find the cause and correct it because if it is a mechanical issue it will happen again.
Have you ever had a crash because of a death wobble, this is where the motorcycle shakes violently from side to side. This is almost always the result of a mechanical issue with the motorcycle. That is why you need to be very careful when making changes to the motorcycle particularly changes to the front end of the bike. If you do make changes make sure the changes do not have an impact on the rideability or stability of the motorcycle.
I would say death wobbles are most often caused by excessive speed or some mechanical issues like mentioned above. If you have experienced this leave a comment or join us on the forums where we will be discussing this video.
Relevant Links from Today's video
MCrider Reflective Decals
