How to improve the stability of Harley-Davidson Touring models by eliminating "wobble"

Let's talk about the evolution of the chassis of Harley-Davidson's Touring models (Road King, Electra Glide, Tour Glide, etc.). In the early models, it was common to hear complaints from certain users of these models about stability issues at high speeds, especially in fast corners.
As in other cases, this "problem" was initially declared as a feature, aggravated by a lack of knowledge of the vehicle alignment process in maintenance workshops. Later, "experiments" began to be carried out at the user level and in the aftermarket industry, until HD took the final step and corrected the problem with an impressive chassis update for these models in 2009.

A little history
The origin of this instability at high speeds ("wobbling" or lateral sway of the bike) is due to the use of a chassis design that dates back practically to the 1980s and which perfectly fulfilled its purpose with the latest 5-speed Shovelhead engines and their successors, the Evolution engines.
When Twin Cam engines arrived in 1999 with their increased torque and power, it became clear that the chassis needed to be updated to meet the changing times.
While the Motor Company was shaping this change, various solutions were already being offered on the road and in the aftermarket, including installing larger diameter wheels and stiffening the engine-swingarm-rear wheel assembly relative to the chassis-fork-front wheel assembly. It's essential to understand that in these models, these two assemblies are semi-elastically connected by tensioners and silent blocks.

New chassis
The main new feature of the 2009 Touring models was their new chassis, designed and built with the latest 21st-century technologies, which virtually eliminated the previous stability problems.
This chassis has fewer welding points, which makes it more precise, thus eliminating the engine-chassis alignment that was common until now and quite uncomfortable for many untrained mechanics.

The engine mounts were improved, and the swingarm was replaced with a multi-section one, providing unprecedented rigidity in these models. Following the popular trend, larger diameter wheels were installed, contributing to improved stability at high speeds.

Stabilization kits
For models prior to 2009 that require it (actually also for models up to the present day), there are various kits on the market that will help us minimize this problem by providing greater rigidity to the assembly, which greatly improves road handling.
A wide variety of accessories are manufactured for this purpose, but they are all basically based on creating a more rigid connection between the transmission and the swingarm axle.

It is vitally important to note that all of this is useless without proper vehicle alignment, so before installing it we recommend you take your workshop manual and check step by step that everything is in order, or failing that, take the motorcycle to a trusted workshop where they can adjust the alignment with a specific tool .

For this technical tutorial we have chosen a kit from Progressive Suspension, specifically their Touring Link Stabilizer,
We liked it because of its ease of installation, and it also doesn't reduce ground clearance.

Let's get to work
The components of this kit consist of a side plate that replaces the right swingarm support, a reinforcement for the lower part of the gearbox, and an adjustable tie rod.

Installation is really simple, once the HD manual alignment process is performed correctly.
Start by replacing the swingarm support plate with the one that comes in the kit.



If the model is after 2002, be careful to insert the provided tab.

The angle bracket is then mounted under the transmission case and everything is tightened to the torque specified in the workshop manual.

The stay is installed and its length adjusted so that it is not forced, and the passenger footrest and exhaust are reassembled if we had removed it (not always necessary) to gain access to the support.

Road test
Now comes the most fun part, after checking the correct tire pressure (essential) and putting on our helmet, we can go out to take wide, fast curves to check the improvement in dynamic performance of our machine. We will see how it is not always necessary to add more chrome, there are things that are not seen but that make us enjoy the route more.

Frank Burguera

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