How to fix the Dyna Death Wobble!

If you own a Dyna, or know someone who does, it's pretty likely that you've heard of the infamous, "Dyna Death Wobble". This can be scary for riders, new and experienced alike. In this blog, we'll go over what it is, how it's caused, and what you can do to fix it!

What is the Dyna death wobble?

There are a few names for this daunting occurrence, such as, death wobble or speed wobbles. Essentially, this is when there is a rapid oscillation of the front end or rear end of the motorcycle.

Why does the Dyna experience this worse than other models?

This is due to the swingarm mount design on the Dyna's. The Swing arm uses a pivot shaft through the transmission case only and has no support through the frame. This causes excessive movement of the entire driveline and pivoting of the swingarm. The driveline/engine and swingarm are all connected and essentially floating on two rubber mounts. This puts a lot of strain on the rubber mounts.

How can you stabilize your driveline?

In our opinion the best way to help stabilize your driveline and help reduce the chance of wobbling is by using a Sputhe Chassis Stabilizer Kit! This bolt on kit includes linkages that attach the engine mounts to the frame. These linkages will eliminate side to side movement however still allow for up and down movement so the engine mounts can still dampen vibration. You will also now be able to adjust the driveline alignment horizontally with the included front linkage. This kit will also help increase the engine mounts lifespan as they are no longer fighting the side to side or twisting action of the swingarm. Check out the product's page for more details.

Other factors that can cause wobbling

On the simpler side, you'd be surprised but something little as a pre-trip inspection can prevent these speed wobbles! The key things to look during your pre-trip inspection for are the tread and PSI on your tires. Your tires are what connect you and your bike to the road, so it's safe to say they're pretty important.

• Tire tread and condition: If you find that your tires have poor tread or are starting to wear unevenly, this can lead to an inferior riding experience and leave you more prone to a front end wobble.
• Tire pressure: Your tire pressure is just as important! A good practice is to monitor your tire pressure and see that it's at the manufacturer recommended specification. Not only will this help with the longevity of your tires, but with the quality of your ride as well. If your tires are off by as little as 10 PSI, you'd be surprised just how differently it rides that if it were at spec.
• Tire age: This will also play a big role in handling and over all ride quality. Old tires will become hard and more slippery. The harder rubber can increase ride vibration and decrease tire grip. A general rule of thumb for the motorcycle industry is to replace tires older than 5 years. The 4 digit date code is found circled on the side wall of your tire. The format is weeks then years (2823 for example would be 28th week of 2023). A new set of tires can drastically improve the overall ride quality of a bike. 

One the more technical side, two other culprits are driveline alignment and steering head bearing adjustment. These are often forgotten about or not often performed as they are more laborsome however these play a huge role in stability.

• Driveline alignment: Ensuring your driveline is aligned will help your motorcycle track straight down the road. Most Harley models have one or two adjustable engine mount linkages. One on the front of the engine and one at the top of the engine. Note Dynas only have a top mounted linkage. These can be adjusted to vertically and horizontally move the driveline. Being that the driveline is connected to the swingarm, this allows the rear wheel to be aligned to the front wheel. There are many ways to check alignment however most require special tools. If you'd prefer to have professional check and adjust your driveline, please reach out to our service department. 
• Steering head bearings: Proper bearing maintenance and adjustment is crucial as it can cause two different wobbles if incorrect or neglected. If the bearings are too tight, the bike will not be able to absorb a wobble and will transfer it rearward. Tight bearings can be caused simply by over torqueing the steering stem or a lack a lubrication due to age or road grime. If the bearings are too loose, the motorcycle will not be able to recover from a wobble and will progressively become worse in the front end. Loose bearings are typically caused by excessive wear. Performing a "fall away" test also requires some special tools as well as a motorcycle jack. Our service department can also help you with this.

End of the road

While there are a few more areas to check for handling issues (suspension, wind shield/fairing, wheel sizes, etc) we discussed the bigger culprits in this article. We hope this helps and has shine some light on any issues you may be experiencing. If you have any questions or are interested in getting your motorcycle riding on rails again, please give us call, email or stop on in! Thank you from the team at Ramjet Racing.