STUB AXLES FOR KARTS WITH AN INTERCHANGEABLE INSERT

TKART Staff

23 November 2016

BirelART has designed and manufactured stub axles for a completely innovative kart: the first that allows a rapid change in bending stiffness without having to remove or replace them

TYPES OF INSERTS

There are three Birel ART standard replaceable inserts: soft (blue interior); medium (no colour); and hard (green interior). The rigidity difference is realised using steels with different compositions and treatments.
The Birel ART racing department has additional options available, with hardness variations of inserts that can be minimal to always find the most suitable technical solution to every situation.
However, in the end, even the racing department mainly uses standard inserts for practical reasons.

NUT TIGHTENING

Another interesting feature of the Birel ART stub axles is the thin and light nut used for fastening the stub axle to the rim. Very attractive in terms of design and certainly advantageous due to the reduction in weight, this nut, however, requires a specific key for tightening and disassembly.
The double attachment hole of the steering arm is instead traditional, adapted to vary the Ackermann angle, like the difference between the model for the OK classes and the one for the KZ classes, distinguished by the presence (KZ) or not (OK) of a support for the front brake calipers.

A thin and light nut to secure the stub axle to the rim

A specific wrench to tighten the Birel Art stub axle nut

Traditional double attachment hole for the steering arms for adjusting the Ackermann angle

A support for the brake caliper, only present in the stub axle of KZ classes