Bump Steer - BOMBARDIER 1996 Ski-doo MX Z440 Handbook

A cross-country carbide does not need to be razor sharp. In fact, testing should be done with a
slightly dulled edge, that way your set-up will be right for the majority of the race. If you test with
sharp carbides, your chassis set-up will be off when the runners lose their edge after 5-10 miles.
The amount of pressure exerted on the rear (or heel) of the ski is controlled by the rubber block that
fits between the spindle and the ski. Excessive heel pressure results in hard steering. Also, ski drag
can be reduced by removing excessive height from the rubber block. This can have a favorable
effect on top speed under certain snow conditions. On newer plastic skis there is an adjustable
steel L-bracket that controls the amount of pressure on the rear-of the rubber block.
, A15F2SS
1. 3 mm (1/8 in)

BUMP STEER

Bump steer refers to the amount of change in the toe out of the skis as the suspension moves
through its total vertical travel. Block up the machine so that the skis are just off the ground and
remove the springs from the shocks. This will allow you to cycle the suspension and measure the
bump steer on your vehicle.
You will need a reference point to measure to as you cycle the suspension through its travel.
Because you will be lifting the ski and suspension assemblies as you are measuring, you should
use a reference point that is not easily bumped out of position. A pair of concrete blocks set on a
line about 50 mm (2 inches) away from the edge of the ski and parallel to the ski works nicely.
Section 03 CHASSIS PREPARATION
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03-79