Suspension Tuning Guide

Ahh, today's sportbikes...aren't they great? Acceleration and power that make the best motorcycles of a decade ago pale in comparison, all rolled up into increasingly compact, yet hospitable packages that don't require Mick Doohan-type skill to access. There's a nice feeling of satisfaction that comes from blowing the doors off of a $120,000 Porsche with a simple twist-of-the-wrist on your $10,000-or-less (insert your brand here) sportbike. In pursuit of that speed, however, the level of sophistication and technology present in the latest two-wheeled machinery has reached unbelievable heights.

That level of sophistication has brought along a few complications. Today's sportbikes not only have incredible straight-line speed, but also their handling capabilities are on par with (if not surpassing) the best racing superbikes of a decade ago. This has required chassis technology to keep pace with the rapid engine development, leading to suspension components bristling with multiple adjustments that can easily confuse the average rider. Sure, spring preload is easy enough to understand; but what the heck is rebound damping? And what does it do with regards to a motorcycle's handling? Should I go toward the stiff end of the spectrum, or the other way? Where do I begin?

Tuning suspension isn't as complicated as it looks; it requires a basic understanding of suspension theory, and how the various components affect suspension action. Once you've got that handled, establishing a basic plan of attack in solving a particular handling problem won't appear so daunting.

What we're going to do in the following pages is make that task of dialing in your sportbike's suspension easier. We'll start by giving you a basic overview of the principles behind spring rates, and rebound and compression damping (no major theoretical essays here; just the basics). We'll also show diagrams that dissect various fork and shock components, and describe how they work so you can see which adjuster does what task.

The next section will include a variety of typical handling problem scenarios encountered by sportbike riders, broken down into two parts: the problem and then possible solutions to start a careful, organized plan of attack. Also included is a detailed chart that specifies handling characteristics that fall on each side of every suspension adjustment (for example, too much compression damping results in this, too little results in that).

There's a section that gives chassis and suspension setup tips for aggressive canyon/street riding, racetrack/riding school days and/or racing; and dragracing, too. And finally, we've included a listing of aftermarket suspension tuning and component companies, so that you can get the pieces and final advice quickly.

This guide will help you gain a better grasp of your sportbike's suspension and how to dial it in to get the most out of your motorcycle. After all, having horsepower is one thing, but if you can't get it to the ground, you'd just as soon be better off on a 50cc moped. Read, learn and enjoy.
-Kent Kunitsugu