Back in 2014, I had an opportunity to sit down and speak with Max McAllister the owner of Traxxion Dynamics in Woodstock, GA. Traxxion Dynamics was started in 1999 to serve riders with top-notch suspension products and tuning services.
We did a little Q&A to go over some questions and theories that came out of some comments on a previous article. “How To: Choose New Tires”. I am reposting this to share insight that was true 6 years ago is still true today.
WC: What effect does changing to a taller or smaller tire have on motorcycle suspension?
MM: The chassis geometry changes, the handling of the bike changes, squat properties change. A taller tire would flatten out the swing arm angle and weights the front of the motorcycle more. This would change turn in, braking force, and stability.
WC: Is it possible to tune the suspension to get back to the same feel like the smaller tire?
MM: It is possible to tune the suspension to alter this back to how the bike handled before the larger diameter tire. There are many other factors that could have an effect on the handling, tire carcass stiffness, and tire profile are a couple of examples. All of these would have an effect on bike handling. Adjustments can be made for all of these conditions to give you the three cornerstones of a good handling motorcycle.
WC: Can you change your suspension to work with used tires?
MM: Yes, but it’s better to replace them. Otherwise when you put new tires on you will have a poor setup for the new tires.
WC: What are these cornerstones?
MM: Comfort, Confidence, and control. We believe these are the keys to a great handling motorcycle. Anytime you can increase any of these it improves all three.
WC: How do you tell someone what a good setup feels like?
MM: A properly set up bike will be stable in a straight line, have a smooth controlled dive under braking to weight the front. The motorcycle should transition into the corners smoothly with a neutral position. No excess pressure on either bar to hole the line in the corner. It’s best to test this on a constant radius corner. When exiting the corner and opening the throttle the bike should go where you point it without squatting or spinning the rear.
WC: Is their a magic street suspension setup for the everyday rider?
MM: Each person has a setting that will work for them. If a stock suspension is too soft or hard for a rider’s weight and stature, no adjustment you can make will work. It needs to be tailored to that rider. A good place to start is internet forums dedicated to that bike. You have to take the information with a grain of salt sometimes but with enough research, you will see a pattern of either setting that people have had success with, or that the components are so poor from the factory that they need to be replaced.
WC: What’s one thing that everyone can benefit from?
MM: Proper tire pressure. Many people adjust this to compensate for a suspension shortcoming. Gold Wing riders were running their front tires at 40psi to prevent cupping. This prevented the cupping but compromised braking, wet weather traction, and cornering. It masked the real problem which was a poorly sprung front fork. It’s also better to replace worn components than to adjust around them.
WC: Can you walk through a “how-to” for the regular rider to find a suspension setup that allows them to be more confident on the street?
MM: Start with deciding if you like how the bike already handles. You need to write down your current settings so you can always go back to them. Nobody wants their suspension to be worse. You have to ask when you make a change, “Can I really feel the difference?”. Changes always seem better at first because they are different, that’s not always the case. You need to really look at whether the change increases the three cornerstone items. Go back and forth between your original settings and the new setting to check.
WC: Want to add anything more?
MM: Suspension works on a bell curve. Somewhere in that range is what works for each rider. We all have a suspension philosophy but every once in a while someone comes along who needs something different or doesn’t fit into that concept. That’s when we go back and make changes to how we think.