SUMMIT
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Summit does not require any specialized knowledge or understanding
of its unique suspension and drivetrain to perform typical, everyday
setup and tuning adjustments. Adjustment procedures for alignment,
spring rate, damping, steering and ride height are covered here.
SUSPENSION TUNING
Springs
Summit’s springs have
been carefully selected
to provide the best
combination of roll
stiffness and bump-
absorbing ability. If you
wish to install softer or
stiffer springs, Traxxas
offers optional tuning
springs. Higher rate
springs are stiffer, and
can be used to reduce
sag, body lean, and brake
dive for a more responsive handling feel. Lower rate springs are softer,
and will increase traction and suspension articulation when traversing
difficult terrain. Refer to your parts list for a complete part number
listing. Springs are identified by dots of color on their ends.
Optional springs available from
Traxxas are listed to the right.
Refer to your parts list for a
complete part number listing.
Higher rate springs are stiffer.
Springs can be identified by
dots of color on one end.
Ride Height Adjustment
Summit’s ride height can be finely tuned by adjusting suspension sag
via the pre-load adjusters on the shock bodies. Thread the pre-load
adjuster down the shock body to raise Summit’s ride height, or thread
the adjuster up the shock body to lower ride height. If threading the
pre-load adjusters to the maximum ride height position still allows more
suspension sag than you prefer, stiffer springs should be installed.
Adjusting the Pivot Ball Caps
The pivot ball caps should be adjusted so
that the pivot balls operate freely in the
axle carriers with no excess play. Use the
provided four-way suspension multi-tool to
tighten or loosen the pivot ball cap.
Rockers
(Progressive Rate/ Suspension Travel)
One of the most exciting aspects of Summit’s suspension is the inboard
shock (damper) arrangement that uses pivoting rockers to translate
vertical wheel travel into linear shock motion. The rockers can be
changed to increase or decrease the maximum wheel travel and also to
change the progressive rate of the suspension.
The progressive rate determines how much the force at the wheel
produced by the springs being compressed (wheel force) will vary with
suspension travel (or vertical travel of the wheel). On a progressive
suspension arrangement, the wheel force will increase at a faster and
faster rate as the suspension is compressed. It feels as though the shock
spring gets progressively stiffer the more you compress the suspension.
On a linear suspension arrangement, the wheel force increases linearly as
the suspension is compressed. The spring does not feel any stiffer, even
when the suspension is fully compressed. This provides a very “plush”
feeling suspension with seemingly bottomless suspension travel.
A total of three different rocker arm sets are available for Summit. All
will allow the wheel to travel a total of 90mm in the vertical direction.
From the ride height position, the wheel will be able to travel 60mm in
the upward direction (bump), and 30mm in the downward direction
(droop). Summit is equipped with the long-travel rocker arms for
120mm of total travel. The progressive rate can be increased or
120mm Travel
Dot Color Spring Rate
Double Yellow 28.0 lb/in (4.9 N/mm)
(Standard Rear)
Double Orange 30.8 lb/in (5.4 N/mm)
(Standard Front)
Blue 33.7 lb/in (5.9 N/mm)
Purple 36.5 lb/in (6.4 N/mm)
TUNING ADJUSTMENTS
Compression 2/3
Sag (Droop) 1/3
Ride Height
Total Travel
Axle Centerline at Ride Height
Axle Centerline at Max Compression
Axle Centerline at Max Sag
Important: The shocks are
assembled at the factory
with a center-to-center
distance (between the rod
end balls) of 87mm. Any time
the shocks are removed and
disassembled, this distance
should be checked to ensure
proper operation of the
suspension.
87mm
Rocker Arm Total Travel Progressive Rate
Progressive 1
90mm
(60mm up / 30mm down)
Low
Progressive 2
90mm
(60mm up / 30mm down)
Medium
Progressive 3
90mm
(60mm up / 30mm down)
High
Long Travel
(stock)
120mm
(80mm up / 40mm down)
Low
