Top Gun Motorcycles
Technical Insights
by Elden Carl
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12/01/2007

Suspension 101

As you may know, we at Top Gun have introduced two custom rear springs (sold by
MMP) for the stock KLR650 rear shock; a 6.6kg and a 7.4kg.  We toyed with the idea of
producing an 8.5 or 9.0kg but were afraid the stock preload mechanism might be over
stressed by such a heavy spring.

Finally a vast majority of 1987 through 2008 KLR650 riders will be able to hold their
rear ends up with out resorting to anything as radical as a raising link.

It’s simple suspension dynamics 101.  If you weigh 200lbs and carry a few pounds of
gear on the rear rack of your stock-shock equipped KLR, you probably have
approximately 5 inches of rider-up sag and around 2.5 inches of usable rear wheel travel.  
You also have increased rake and trail to the tune of approximately 29 degrees and 4.7
inches respectively; which will make your bike handle on the street more like a wheel
barrow than a proper KLR.

You can get your rake and trail back to factory specs by raising the rear of the bike with
raising links, but you still only have approximately 2.5 inches of usable rear wheel travel
under the above circumstances.  If you install Top Gun’s new spring and a raising link you
will get your proper ride height and 5 inches of usable rear wheel travel back but now you
have a twitchy, stink-buggy (high in the rear) KLR you wouldn’t want to take off road
(approx. 27 degrees and 4.1 inches rake and trail).

It’s that simple folks; you lift up the sagging back of your bike with a spring - not raising
links.

In my garage there are three KLR650 shocks (Ohlins) and three sets of custom links.  The
closing lengths of the shocks match the links which are (A) stock, (B) lower the rear
.800”and (C) lower the rear 1.200”.  Rear shock set-up (A) is for street with stock rake and
trail, (B) is for rocky to moderately decomposed-granite conditions, and (C) is for sandy
conditions common in northern Baja. (Todd's Note - most of us only have one shock, but
you can safely lower the KLR .8" without having to restrict rear shock travel. Having a
second set of links is an easy way to transform your street bike into a better dirt bike for
off-road use. The increased rake and trail will give you slower, more stable steering for
loose conditions.)

Crashing is not good for the human body or the bike and should be avoided at all cost.  
Riding ability, proper load distribution, stable steering, good suspension, proper tires
inflated with correct air pressure are very important to safe riding.

One of the most famous sayings in motorcycling is: “more trail, less flail”.  If your raise
the back of the bike and load it down up front with all kinds of stuff, do yourself and your
bike a favor and stay on the pavement.
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