Tech Focus | AP06, the new Parolin Racing Kart braking system

Back

Exclusive Content

Tech Focus

AP06, THE NEW PAROLIN RACING KART BRAKING SYSTEM

Max Bernardi

18 June 2018

The braking system is undoubtedly one of the most crucial elements in the performance of a kart. During the 2018-2020 approval session, Parolin Racing Kart decided to renew its AP05 model, keeping all the strong points, but improving its rigidity and, therefore, its braking capacity. Let's find out about the secrets and latest technical features of the new AP06 braking system

The starting point of the new AP06 baking system is the previous AP05 model, highly appreciated for its performance and strength. Based on this, and thanks to the experience gained on the track by the Parolin Racing team in international competitions, the technicians of the Italian company continued its development, aiming to increase the system’s performance. The pads and pistons are the same size, given that the AP05 proved to be reliable from the point of view of tyres and it had been continuously updated over the years. The focus was instead on increasing rigidity and reducing torsion during braking.

THE PROJECT

As with all Parolin Racing kart accessories, the design of the baking system also started with the technical department, where the drawings of components are developed using 3D drawing software. The first prototyping phase takes place using a 3D printer, which quickly develops a prototype with the dimensions and actual shape of the brake caliper. This allows you not to stop the CNC machines used for its production and, at the same time, check the dimensions and machining. The subsequent phase is the actual production and, after this, testing on a track, which are essential for checking all the new components of the baking system.

REAR CALIPER

The main changes with respect to the previous approval focused on the rear caliper: in the new AP06 system it is no longer made using two half-shells, but is completely made from a monoblock of aluminium, which ensures less bending and, therefore, greater rigidity. All this translates into an increase in braking force. The Parolin technical department redesigned the internal oil channels from scratch, a noteworthy effort which, however, produced remarkable results. Being a monoblock, the pincer is also less complicated for maintenance purposes: obviously, the fastening screws and o-rings between the two half-shells are not there, and moreover the brake bleeding is simpler, since it is only carried out once.

RADIAL MOUNT

Another novelty of the AP06 system concerns the caliper attachment, now in athe radial version. This modification allows limiting torsion when braking, but above all it is advantageous in speeding up the dismantling of the caliper from the coupling, unscrewing the two fastening screws without having to loosen the brake disc hub. The brake disc is a floating and self-ventilated one, and the standard version has a diameter of 180 mm, although there is also a 195 mm brake disc as an option.

WEIGHT

The monoblock has made it possible to considerably reduce the weight of the caliper which can also be noticed from an aesthetic point of view due to its more compact dimensions. Furthermore, the various CNC machining processes have also favoured heat dissipation capacity, an important factor in ensuring high level performance continuity under stress.

BRAKE PUMP

No changes compared to the past for the brake pump with oil recovery tank. This regards an element made from a solid aluminium block, with a 22 mm diameter piston inside. A characteristic lever is fastened to the rod connected to the brake, which is longer and has three anchoring positions to give the driver more options to choose from depending on braking preferences: the lower the rod is fastened, the greater the force to be exerted on the brake pedal (whose stroke is shortened). The higher the lever is fastened, the more the pedal stroke lengthens and the braking force decreases.

BRAKING DISTRIBUTOR

The braking distributor, already developed for the old braking system, is designed to have the widest adjustment stroke between the front and rear (obviously this only concerns systems that have both front and rear brakes). The adjustment is made by a "ratchet" which moves four positions at each turn, with each position being a ¼ millimeter. The positions are identified by a click thanks to the machining performed on the knob, which allow you to understand the movement on the distributor.

The braking distributor, like the entire baking system, was also designed to reduce weight

FRONT BRAKE CALIPER

The front brake calipers are the same shape as the rear calipers but are more compact. There are two 27.5 mm diameter pistons inside. They are also made from a solid block of aluminium and machined by CNC machines that allow a precision of one hundredth of a millimeter. The radial attachment, designed to reduce torsion during braking is also at the front. The tapered shape allows the greateest possible reduction in weight while maintaining the rigidity of the caliper thanks to machining from a solid piece. The reduced weight is also fundamental from the point of view of the rotating masses, external to the central axis of the kart; in fact, these must be as light as possible to improve the behaviour of the chassis on long bends.

Comparing front calipers: the new AP06 model, above, and the previous AP05, below

The front discs are also floating and self-ventilated. They are 150 mm in diameter

PADS

Three different pads can be used for the new AP06 baking system: hard, medium and soft. Each, of course, has a different degree of hardness of the friction material, allowing drivers to find their best feeling with the braking system depending on their driving style. The pads are deliberately small in size: in fact, the Parolin technicians believe that only force exerted by the piston against the pad directly affects the disc. Larger pads are likely to carry less thrust in the external areas. The housings of the pads are fitted with magnetic pistons to allow them to return to their correct position once the disc has been clamped.

FRONT HUB

Great attention has been paid to the front disc hub, developed in the smallest details starting from a CNC machined 90 mm diameter round bar. By analysing it you can appreciate the triangular side openings, made to reduce weight. They are placed in a position not parallel to the horizontal axis in order to ensure more mechanical resistance to the hub and, therefore, more rigidity. Also from the point of view of heat dissipation, generated by the friction between the disk and the pad, the hub has the important task of favouring the escape of hot air through the openings.

The triangular openings reduce the weight of the front hub and favour cooling

RADIAL MOUNTS

Lastly, the new attachments are also interesting, and as mentioned earlier, they are in a radial position: a position that reduces the torsion of the brake caliper during braking. Obtained from a solid piece and tapered to reduce weight, the front and rear attachments facilitate the dismantling of the brake caliper. The new system, especially in relation to the rear caliper, allows the speeding up of system maintenance activities and making changes to the chassis setup.

In the AP06 baking system the atatchments of the front and rear calipers are radial