THE NEW FL HI-TECH STEERING COLUMN AND SUPPORT

Max Bernardi

08 January 2021

Freeline, the Birel ART accessory division, has devised two innovative solutions. The first one, which is patented, aims at eliminating the flexibility limitation of the chassis which usually the steering column offers, while the second solution allows to quickly vary the steering geometry

The steering column has the task of transmitting the rotation of the steering wheel to the wheels. In karting, it is a simple 20 mm tube to which the steering wheel hub is fastened to in the upper part while, in the lower part, it is equipped with plates which the steering rods are connected to. The steering column is anchored to the chassis in two points: the lower part by means of a threaded pin that fits into a special support of the frame whereas, in the upper part, most of the chassis adopt a bushing made of a plastic material which has the task of holding the steering column in place while still allowing its rotation.

UPPER BUSHING

When designing the FL HI-TECH steering column support, Birel ART technicians focused on eliminating the torsion constraint that the chassis has in the steering column that is inserted into the plastic bushing in the upper fastening of the steering column itself. The decision to change this detail is due to the fact that the steering column is not aligned between its lower and upper connection points, because of the off-centered angle towards the left of the upper support. The displacement, present on all chassis, serves to balance the weight of the engine with that of the driver, thus improving the distribution of the weight on the kart. The upper support, which is not aligned with the lower one involves an additional step, during the assembly of the steering column, for the slight bend of the two arms to which the plastic bushing is attached to. This action is needed because the two support tubes above the fuel tank can return to their original position, creating tension on the column. Furthermore, the steering column, restricted in a fixed way both at the top and at the base, creates a constraint when the kart enters a turn, thus limiting the torsion of the chassis in the front area. Precisely to eliminate these issues, the new FL HI-TECH steering column support has been equipped with a ball joint which allows a perfect alignment between the upper bushing and the lower attachment while supporting in real time the torsion of the chassis when cornering as well.

The new system designed by Birel ART is installed between the two fastening tubes of the fuel tank and replaces the previously version used with a fixed plastic guide.

The plastic guide used in the support’s previous version did not allow the steering column to move freely, thus creating a constraint in the chassis torsion.