Fuel For Thought
by Rod Morris
Copyright © 2006 Top Gun Motorcycles. All rights reserved.  Distribution or publication of this document (electronic or otherwise)
is prohibited without the express written consent of the author. For more information or to request permission to publish this
document, please see our
contact page. For information on our pledge to maintain your privacy click here. To learn more about
your friends at Top Gun Motorcycles, read about us
here.
09/09/2011

Welcome To Fuel For Thought

Written by: Rod Morris

Glossary of terms and abbreviations:
MSM - Multisurface Motorcycles/Motorcyclist
MMP - Multisurface Motorcycle Products
TGMP - Top Gun Motorcycle Products

MSM Weight Classifications:
Lightweight (LW) - up to 250lbs
Middleweight (MW) - 251lbs - 300lbs
Light-Heavyweight (LHW) - 301lbs - 350lbs
Heavyweight (HW) - 351lbs - 400lbs
What's NEW!
Top Gun Motorcycles
Happy KLR650 Owner

"I got my spring within a few days of sending. Installed it with some rachet straps.

I had raising links on the KLR but changed back to stock. I'm running the shock with the
pre-load on the first position. It works perfect and eats the bumps.  I wish I had bought
a spring sooner and saved my $80 on the links. I used to sag my KLR about 5", now it
barely sags at all and I actually get the range of travel it should.

Nice product and thanks for great customer service. I will recommend TOP GUN to my
friends.

Stu"

Note: According to suspension experts contacted, the "only" correct way to get proper
sag height and ride height is with the proper spring.

What Happens To My KLR650 Shock

We get many questions on what spring would work best for certain load weights and
our answer is always the same. We use total load weight that's on the bike "ALL" the
time. That's the rider with normal riding gear on and any other added weight like boxes,
bags, bars, tool kits, guards etc. The key to the answer is the load weight "ALL" the
time. How much load weight that's on the bike if you rode every day to commute with
the same briefcase, tool bag, side bags to carry a computer, notebooks or whatever.
The spring rates that we suggest are always with the pre-load on a lower setting so
that when you occasionally add a passenger or extra heavy load of camping gear,
there are up to 4 more pre-load settings available. Remember, "one spring does not fit
all situations". The only other option for always having the correct spring rate is to own
a second shock set-up for those situations or be able to easily change the spring when
needed.

Every stock motorcycle shock and forks will eventually need to be serviced. We've
found that the KLR650 shock can need servicing as low as 3000 miles or as high as
25,000 miles depending on the type of riding and other factors. Rider weight, load
weight and type of riding conditions are three of the most common factors that affect
how long the stock shock will go before needing a service.  
Don't let this happen to your bump
rubber
Here are some of the reasons why the
KLR650 shock gives out sooner than
some others. The main culprit is the
wimpy stock shock spring. It has a
rating of about 5.1kg as compared to
our 6.6kg, 7.4kg and 8.0kg which were
all designed specifically for the
KLR650 shock instead of the "one fits
all" concept of some other aftermarket
units. We've found that the 7.4kg
spring is the most needed rate for the
average KLR650 owner (more sold
than any other rate) which means that
"total load weight" for this group is
between about 230lbs to 280lbs. When
you compare that to the stock spring
you can see why it doesn't take much
of any type of riding to pound the poor
shock into submission. Two things
happen when the spring is too soft –
not only do you slam into the bump
rubber more frequently, as you slam
down on the poor quality bump rubber
some of the parts inside the shock are
suffering harsh abuse and wear out
quickly. In some cases we get a shock
with the bump rubber in various stages
of destruction with a few of them totally
missing.  

There are two main components inside
the shock body that basically control
compression and rebound. The piston
and shim stack are at the top which
controls the oil/nitrogen mixture to
keep the compression smooth. Luckily
the piston never seems to wear out as
we've never needed to replace one.
The seal head is down lower and has
two rubber seals that the shock shaft
rides through. Unfortunately, the two
seals wear out extremely fast when the
stock shock is getting beat-up and
almost always need replacing.
Rebound is controlled by the damping
wheel (A models) or screw (E models)
located on the outside at the lower
shock end. We recommend starting
out with both types on #1 setting as
the oil holes are biggest there and
provide smoother damping. Adjust as
necessary.

At the first shock service we always
recommend installing the proper spring
at the same time.   Basic service
includes new oil, nitrogen, high quality
bump rubber, inspect the shock, and
clean and lube the pre-load unit. When
you include a spring of your choice we
install it at no extra charge.

Most customers that install the proper
spring comment that it's the single best
improvement they've done to their
KLR650.

Avoid this DR650 Mistake

This is going to sound like the most
basic and simple thing that just couldn't happen, yet it does - getting the oil filter in
wrong at oil change. When you remove the oil filter cover you find that it has a small
spring pushing the filter. You remove both, remove the old filter, clean out the excess
oil and install a new filter (every other oil change).
How hard can that be? It's not hard, but a simple mistake can leave the engine in
potential danger. The silly little spring can and has been installed against the engine
with the filter pushing against it. The oil cover goes on fine and you think all is well until
next time. That spring is there to help press the oil filter against the engine for a tight
seal. When installed wrong the filter collapses the spring but leaves a slight gap that
allows unfiltered oil to enter the engine. It may not be very much unfiltered oil but who
knows what gremlins get through and end up in bearings or other sensitive areas.

We don't know of any damaged DR engines (yet) attributed directly to this error but the
potential exists, so be careful.

KLR250

There are a great many KLR250 owners in the same boat as KLR650 owners in that
they all need a better shock spring; so we started inquiring around. There were a few
unconfirmed rumors that the KLR650 shock fit the KLR250 but we couldn't find a
reliable source other than a comment on a KLR250 blog. We also had KLR250 owners
asking if our KLR650 shock spring would fit their shock. Again we had no definitive
answer. We even tried to find a used KLR250 shock on Craigslist and eBay that we
could at least try our spring on but to no avail.

A KLR250 owner recently asked the same question but went much further after we told
him we just weren't sure our spring would work. He did his own detective work and
found a thread which indicated that our spring indeed would work on the KLR250 shock
and he wanted to order not only a shock spring but a set of forks spring too. Below is
his e-mail after I sent him the parts

“I installed it (spring) today without much trouble. The new spring is a bit shorter and
the outside diameter is a bit larger than the stock spring, but not enough to cause a
problem.

"I installed the upgraded fork spring this weekend too. Pretty good upgrade for a total
of $200, front and rear.  Paul W.”

Paul picked up a lot of his information at www.klr650.net.

We'd still like to know if the KLR650 shock would work if anyone has that info.
Stock shock components before
rebuild
Rebuilt components ready to
install
Ready for action!