|Welcome to Ultramax Support
at Ultramax Racing Chassis, we put a tremendous amount of effort
into each and every product we put on the market. However, we
realize that it is not enough to give you the highest quality
product that we can produce...
That is why we are dedicated to making sure that you get the
most out of our product through our technical support programs
and online owners manual area offered on this site.
Start Owners Manual Area:
This setup tutorial is
designed to do just that by familiarizing you with your
Ultramax Chassis and giving you the necessary information
on chassis preparation and setup analysis that will
put you ahead of the pack for the next racing season.
Although this tutorial Mentions just one of our chassis
designs, the instructions do apply generally to all
of our chassis. In the following pages we are going
to break down the process that we have found to be most
successful in assembling a chassis once it is received
from the factory. We will cover topics like squaring
and alignment, front end geometry, seat and body mounting,
at the track setup analysis and several other important
issues that are necessary to keep you out front for
future racing seasons and beyond.
1 - Out of the Box
The first thing that should be done when you receive
your chassis is to make sure that you have received
all of the necessary equipment from the factory. We
try very hard to include everything needed to put the
finishing touches on your chassis once you receive it
but hey, we tend to make mistakes from time to time
just like everyone else. So, keep us in check and go
over this quick check list to make sure that you have
all of the necessary equipment to make your assembly
process a quick and easy one. The following things should
be included in every chassis purchase:
2 Squaring and Alignment
and right side seat strut along with 4 bolts
and nuts for each strut and seat hook up point.
wheel with hub, three bolts, three nuts and
three cotter keys.
wheel nuts and 6 sprocket hub nuts.
column lock and pin.
Once you have made sure that all of the necessary
components are there, you are ready to move
on to step two which many consider to be the
most important step in assembling a new chassis.
One of the most important parts of assembly on a new
chassis is making sure your chassis is square from front
to rear and that all of the front end geometry is set
to your desired specifications.
It is very important that a certain process is followed
when setting your front end geometry and squaring your
If the process is not followed, your front end may get
out of align with itself and the rear axle giving you
poor scaling consistency and on track performance.
In this section, we will outline this step-by-step process,
breaking down each step for a better understanding of
its roll in your chassis on track performance.
Step 1 Leveling your Chassis
It is a good idea to level your
chassis when setting your front-end geometry so you can take
accurate measurements when setting up your front-end. A surface
plate used when scaling a chassis works well in completing
Simply level your surface plate and leave the scale plates
off. Without wheels or tires, place the chassis flat on the
surface plate and make sure that it is stable and level on
You are now ready to move on to step two.
Step 3 Setting your Caster
2 Setting Your Pitman Arm
Front-end geometry consists of a series of angles that set
your caster, camber, king pin inclination and Ackerman. Each
angle must be set correctly and work together with one another
in order for your front end to work at its optimum level.
The first step in doing this is making sure your pitman arm
is set perpendicular to your level surface as shown in the
picture on the left.
A digital smart level that can be found in any hardware catalog
is a good tool to have when completing this step. To check
its alignment, simply place the smart level parallel to the
pitman arm on each side and turn the steering shaft the necessary
direction to get the two angles to equal. The angle that you
are looking for is around 4° - 5° on each side.
Once this is completed, lock your steering lock down on the
steering shaft and place the locking pin in it. You are now
ready for step three.
Each chassis comes with the right front caster set at 10° and
the left front caster set at 8°. These settings are obtained
when both sides have the center notches lined up on the caster blocks
as shown with the left front in the center picture below. For almost
all conditions, these caster settings will be a good starting point.
However, there are certain situations where a different setting
may be desired for a better weight jacking effect. For this case,
both the right front and left front caster blocks come equipped
with three lines both forward and backward from the original notch.
Each line forward or backward is a 2° change in caster. Therefore,
on the right front you can go as low as 4° of caster or as
high as 16° of caster. Similarly, on the left front you can
go as low as 2° of caster or as high as 14° of caster.
The following figures illustrate how this works using the left front
as an example with the picture on the left set at 6°, the middle
at 8° and the right at 10°.
built into a racing chassis to promote weight transfer,
which is a major factor in producing the bite necessary
to negotiate each corner on the track. Generally, more caster
will produce more weight transfer and more bite and less
caster will produce less weight transfer and less bite.
So, on high speed, hard biting racetracks, less caster will
be needed since the racetrack itself will be producing most
of the necessary bite. Similarly, on low speed, low biting
racetracks, more caster will be needed in order to produce
the necessary amount of bite in the chassis.
Running more caster in the right front than the left front assists
the kart in turning left on corner entry, this is known as caster
split. The more caster split that is ran, the more the chassis wants
to pull to the left thus, helping the kart turn on corner entry.
In a situation of too much caster split, the kart will generally
turn in very well on corner entry but pick up a push at the apex
of the corner due to an insufficient amount of weight jacking by
the left front. If there is not enough caster split in the front
end, the driver will have to apply a lot of input to get the kart
to turn getting into the corner, making the kart feel tight in the
front, or possibly twitchy in the rear, on corner entry.
A few good rules of thumb on caster for those who are less experienced
with it are as follows:
2° of caster
split is a safe amount of split for most all conditions. If you
are not experienced with caster or simply dont like to adjust
it much, this split will be the best overall setting for you. It
is our recommendation that you dont exceed 4° of split
and never run less than a 0° split.
Using the right front as a baseline, we have found that
you will generally not need to run more than 14° of caster.
Most times if you run more than this you will create too much weight
jacking to quick and will be unable to keep the kart consistent.
Likewise, 6° of caster is the least amount we recommend running.
Lower settings than this tend to cause a pushing condition due to
a lack of weight jacking.
Naturally, these are simply guidelines to follow. Every racetrack
is different and may require caster settings outside of the parameters
we have outlined above. However, if you stay within these parameters,
we feel confident that your front-end settings will be within a
safe range and should be sufficient under most conditions. Now that
your Caster is set, we are ready to move onto step 4.
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by Ultramax Racing 2595 Rutherford Road Greenville, SC 29609
Tel. 864-322-0504 Fax 864-322-0266