Unlike when Mr. Webb and Mr. Lawson started riding on their Hodaka “Swamp Rats” with no major adjustments to speak of, today’s motorcycles can be customized to fit each individual rider with factory precision. With modern motorcycles being so adjustable, there are few things that confuse the Dirt Bike magazine staff more than dialing
in suspension settings. Is it riding too high in the back, pushing the front end in corners, packing, rebounding too
fast, or could it just be the track conditions today? These are all questions that arise that make our heads explode.
Starting with the basics
SUSPENSION 101 WITH
PRECISION CONCEPTS’ BOB BELL
Step one, and always the starting point, is to make sure
you have the proper spring for your weight and riding
ability. Spring rates are determined by rider weight, rider
height, type of riding and bike. There is no simple formula,
but there are some basic guidelines.
Start with the shock and the ability to set sag. There are
two types of sag associated with motorcycles: rider sag
and static sag. Here is the process to check sag: First, put
the bike on a stand with the wheels in the air; be sure that
your swingarm, linkage and shock bearings are in good
shape. If they are worn out, the sag measurements will not
be accurate. Take a measurement from the rear axle to a
straight-up point on the rear fender. This will be the refer-
ence point of “0.”
Now, take the bike off the stand and sit on it at the front
of the seat where it begins to slope up. It’s helpful if you
have an additional person to balance the bike; otherwise,
Once you have decided on a rear spring, you will need
a matching front spring. Most suspension shops can help
you here. One note: you should have your spring rate test-
ed. There is a variance from the manufacturers, and if your
current spring tests either low or high, you may be buying
the wrong spring.
Ride height can also be adjusted. A tall rider will make
the bike pitch more front to back than a shorter rider. Also
four-strokes pitch more, especially under braking.