Traxxas 56076-1 - Manual (Page 22)

22 • SUMMIT
TUNING ADJUSTMENTS
decreased by installing different rocker arm sets. The rockers are labeled
Progressive 1 to Progressive 3. Progressive 1 rockers will provide a low
progressive rate that maintains consistent damping force across the
whole range of suspension travel. Progressive 2 rockers provide a larger
degree of rate change, and Progressive 3 rockers have the greatest rate
difference. Progressive 3 rockers will improve high-speed cornering on
smooth surfaces by providing a firmer feel. Remember that Progressive
1, 2, and 3 rockers all provide 90mm of travel, 30mm less than the
Summit’s stock 120mm long-travel rockers. This may improve road
handling, but will reduce suspension articulation in rough terrain. Body
roll, brake dive, and rear squat will also be reduced. Always change all
four rockers as a complete set. Do not mix rates and travel.
When using the Progressive 1, 2, or 3 rockers, Traxxas #5439 springs
(3.8 rate gold) provide a good starting point for suspension tuning.
The chart below demonstrates the effect of the various rocker arms on
wheel force as the suspension is compressed. On the progressive rate,
wheel force is light at first and increases as the suspension is compressed.
SHOCK TUNING
Shock Oil
The 4 oil-filled aluminum shocks (dampers) effectively control the
suspension movement by preventing the wheels and tires from
continuing to “bounce” after rebounding from a bump. Changing the oil
in the shocks can vary the suspension damping effect. Changing the oil to
a higher viscosity oil will increase damping. Lowering the viscosity of the
oil will cause the suspension damping to be reduced. Damping should
be increased (with higher viscosity oil) if the model is bottoming easily
over jumps. Damping should be decreased (with thinner viscosity oil) if
the model is hopping over small bumps and feels unstable. The viscosity
of shock oil is affected by extremes in operating temperature; an oil of
certain viscosity will become less viscous at higher temperatures and more
viscous at lower temperatures. Operating
in regions with cold temperatures may
require lower viscosity oil. From the
factory, the shocks are filled with SAE-
50W silicone oil. Only use 100% silicone
oil in the shock.
Replacing Shock Oil
The shocks have to be removed
from the vehicle and disassembled
to change the oil.
1. Remove the lower spring retainer
and shock spring.
2. Remove the upper shock cap
using the shock wrench and the
suspension multi-tool.
3. Empty the used shock oil
from the shock body.
4. Fill the shock with new silicone shock
oil up to the top of the shock body.
5. Slowly move the piston up and down
(always keeping it submerged in oil)
to release the air bubbles. Let the
shock sit for a few minutes to allow
any remaining air bubbles to surface.
6. Slowly thread the upper cap with the installed shock bladder onto
the shock body with the suspension multi-tool. The excess oil will
bleed out of the small hole in the shock cap.
7. Tighten the shock cap until snug. Use the included steel shock
wrench to hold onto the shock body while tightening.
Shock Pistons
The shock pistons can be replaced with the available optional pistons to
vary the amount of damping. Optional pistons with bypass holes that
are larger or smaller (1, 2, or 3) than the factory-installed stock pistons
can be used to decrease or increase damping respectively. Change the
pistons if you only have one weight of shock oil available to you. From
the factory, Summit is equipped with #2 pistons in the front and #2
pistons in the rear.
Constant Rate Travel
Wheel Travel
Wheel Force
0
2
4
6
8
10
12
14
16
18
20
10 20 30 40 50 60 70 80 90
Progressive Rate Travel
A. Tighten/Loosen Upper Cap
C. Remove/Install Rod End
B. Tighten/Loosen Lower Cap
Multi-tool Shock Functions
All of the toe links are installed
on the truck so that the left-
hand thread indicators point
to the same direction. This
makes it easier to remember
which way to turn the wrench
to increase or decrease toe
link length (the direction is the
same at all four corners). Note
that the groove in the hex
indicates the side of the toe
link with the left-hand threads.
A camber gauge (available
at your local hobby shop)
can be a useful tool for
alignment setting.