|To have good working suspension, there are several
things you need. If you skip a few steps - your suspension will
never be what it could be.
1. You need the correct up travel of the front and rear wheels.
2. You need the correct down travel of the front and rear wheels
(also referred to as droop).
3. You need the correct progression in spring rates in the front
to keep from bottoming and from rolling in the corners to much.
4. You need the correct progression in spring rate and valving in
the rear to give a plush ride and still keep from bottoming.
5. You need the correct valving inside the shock.
6. You need the have the ride height set correctly.
7. You need to have the rebound and compression adjuster set
8. The front and rear of the quad need to be balanced (ride
height and shocks must work together).
Some of these items are easy for you to check and adjust - some
need to go to a shock expert to have a few adjustment made - and
some may require different parts to be installed on your quad to get
the best ride possible.
First lets take a look at each one and how it effects you ride
1. If you have too little up travel of the front wheels - your
quad will hit the bumper (on the shock) to early and you will need
to compensate by running a much stiffer setup due to the lack of
front wheel travel.
If you have too much up travel of the front wheels - your frame
can hit the ground.
If you have too little up travel of the rear wheels - your quad
will hit the bumper early and kick the back end up very easily.
If you have too much up travel of the rear wheels - your frame
will hit the ground.
2. If you have too much down travel of the front wheels - your
quad will roll to much in the corners - the front end will come up
to high in the front when accelerating giving you poor steering
control of you quad since it is transferring too much weight to the
If you have too little down travel of the front wheels - you will
need to compensate for the lack of travel with with a very stiff
front end to keep from bottoming - the front end will then dance
over the rough terrain instead of tracking the ground nicely.
If you have too much down travel of the rear wheels - your quad
will roll on down hill corners as the rear comes up to high and
transfers to much weight to the front - the back end will also swap
side to side when braking in rough terrain as the back comes up to
high and will not track the ground nicely.
If you have too little down travel of the rear wheels - you will
need to compensate with excessive spring preload and a stiff shock
to keep from bottoming due to the lack of wheel travel.
3. The front spring curve can be built with various
combinations of springs, spacers, and crossovers. A few things to
look for in a good spring curve - lift up on the front of the
quad till the shocks fully extend - now push down on the front of
the quad - it should be a nice smooth transition thru the down
travel with no distinct changes as the springs crossover into the
next spring - push down on the front of the quad several times and
then let go - the upper spring should be supporting the weight of
the quad without hitting the crossover point - now have someone the
same weight as the rider stand on the pegs and do this again - the
extra weight will let you push the front end down further into the
travel so you can feel more of the spring curve - everything should
still be smooth - push down several times and let go again - the top
spring should now be 1/8 - 3/8 inches close to hitting the crossover
point - again the top spring should be able to support the quad and
The combination of the center spring, if there is one
and the main spring is the next thing to check - with the rider on
the pegs - push down on the front bumper until you have most of you
weight on the bumper (150#) - now look to see how far the body or
seal head is from hitting the bumper - bounce down on it gently and
then recheck - you should have a distance of 3/4 to 1 inch before it
contacts the bumper when you have about 150# on the bumper and the
rider standing on the pegs - you should also be able to gently
bounce down and almost hit the bumper without hitting any harsh
spots in the spring curve - if there is harsh spots in the spring
If you spring curve is to progressive - it will be to soft
at the top of the travel, to stiff at the bottom of the travel, and
will give you a harsh ride. If the spring curve has to little
progression - it will act like a single spring and bottom easily on
any hard hits - it will also roll a lot in the corners.
FAQ#1: What is a crossover??
A: The crossover is a part that
makes contact with another part and transfers the remaining increase
in pressure to the main spring. That can be different looking parts
on different shocks. The first photo is of the crossover that is
used one one stock shock conversion. The second photo shows how the
crossover fits on the shock. The third photo shows the shock and
crossover with the spring installed. The fourth photo shows the
shock compressed to the point that the crossover is 3/16 inch from
hitting or crossing over. The last photo shows the shock compressed
to the point where the crossover contacts the collar above it and
all the remaining pressure is going into the main spring.
What should my ride height be??
A: That is a loaded question that
does not take into account how your shocks are built. If the
compressed and extended lengths of your shock are correct for you
quad, application, and components - then your race sag should be
around 4.5 inches for XC, 3 inches for dunes, 3.5 inches for TT, and
5 inches for MX - depending on the track or terrain you are riding
on. If you setup your quad by ride height alone - you can take a
perfectly good set of shocks and jack up the quad so bad it will
never handle right. Measuring ride height is essential as a reference
especially when calling in for technical support.
How do I measure my race sag??
A: Have someone lift up on the
front and back of your quad till all the suspension is stretched out
to its max. Then measure the distance that the bottom of you frame
is from the ground, both front and back. That should be from 11.5 to
12.5 inches on an XC quad, 12 to 13 inches on a MX quad, and 7.5- 8
inches on a TT quad. Then have the rider stand on the pegs and
measure the frame to ground measurement again. The difference of those
2 measurements is your race sag.
FAQ#4: What should my
distance to crossover be??
A: First off the race sag needs to be
set where you be be riding it before you worry about the crossover
distance. Adjusting the race sag will effect the crossover distance.
Be sure to measure your distance to crossover with the rider
standing on the pegs. The crossover distance should then be 1/8 to
3/8 inch. The lower the number - the better it will corner and
the stiffer the shock will feel - a longer distance will give you a
FAQ#5: What do I do if my quad rolls to
much in the corners??
A: First make sure you race sag is set
correctly, then verify that the crossover distance is within range.
You can then either install a longer crossover or run the next
stiffer main spring.
FAQ#5: How much progression do I
want in my front spring curve??
A: Your front spring curve must
work in conjunction with the shock valving to provide the plushest
ride possible without bottoming harshly. If the spring curve and
valving combination is to stiff - you will not use all your travel
and will have a harsh ride quality. You want the combination of
valving and spring curve to allow you to use all your travel yet
still provide good cornering and bottoming resistance. It is a
balancing act and what works for you may be too soft or stiff for