Troubleshooting guide

Bearing Carriers:

The axle bearing carriers can have an influence on the axle stiffness since the portion of the axle

between the bearing and the hub is the part that flexes. If you widen the rear track, you are losing a bit

of traction because the distance from the bearing carrier to the hub is greater. The normal installation

is with the long bearing race (carrier) pointed inward.

To effectively soften the rear axle a bit, the third bearing can be set loose in the frame housing. The

normal bolts are replaced by bolts of a smaller cross-section and the bearing is not secured with locking

screws to the axle.

Turning the long race of the axle bearings outward will stiffen the axle ends and gain grip. Bolting the

third bearing securely in place and tightening the set screws to the axle will also stiffen the axle and

increase grip.

Remember, the bearings all function like fulcrums with the axle working like a lever, so the flexing on

both sides of the bearings affect the overall stiffness of the rear assembly. If the bearing is not moving

smoothly in the hanger, it can absorb and release energy in an uncontrolled manner which can cause

hopping in the corners.

Rear Axle Assembly Run-Out:

The wheels, axle, hubs and tires will all inevitably have a certain amount of run-out or deviation from

being perfectly round. Sometimes these small individual irregularities can add to each other to form a

significant out of round condition. This will, in effect, often feel like an out of balance tire and will tend to

upset the kart at the middle and exit of the turn when dynamic loading is greatest.

The kart may feel loose and hoping, but the effect can be subtle to the driver. The tuner may keep

trying to tighten the kart to the point of binding, but the problem could be run-out.

Careful assembly of components will help minimize run-out by using the irregularities of each individual

element to balance each other and not provide a cumulative problem.