The 2010 Racing chassis line takes benefit from the important development done by Birel Motorsport in agonistic field. This constant work has allowed some evolutions on three models with Cik-Fia homologation, that are the RY 30-S2, RY 31-S2 and RX 32-S2.
Among the “visible” novelties there are the “C” spindles, which will have a smaller dimension and provided with a more functional eccentric bushing system, with a 4mm screw, able to ease the camber and caster adjustments. Moreover, the reinforcements on the rear bearing cases have been removed, so to guarantee the chassis a better fluency.
In the end, a new support of the seat has been introduced on the right part in order to improve the balance of the chassis and the place for the engines. From the production point of view, it must be underlined the excellent quality control that Birel chassis have to face during each working phase, so much that even the racing division races with standard karts.
From the technical point of view, the RY 30-S2 model is created with 30mm tubes and it is characterized by a front axle design with the spindle “C” anchored to the front crosspiece and a sole torsion bar. It is very versatile and suitable for every kind of category, resulting very “free” and “fluent”. The RY 31-S2 model has the frame metal struts in 30mm tubes, whereas the crosspieces are made with 32mm tubes.
The “C” of the spindles are anchored at the bigger torsion bar height, where the metal struts join the front crosspiece. There are two torsion bars: the bigger one acts on the front axle behaviour and the smaller one increases the rear axle stability.
This model offers a slightly higher grip compared to the 30mm tubes version, whereas for less rubberized and slippery tracks, a better feeling can be found with the RX 32-S2 model, which has a frame completely created with 32mm tubes. The design is very similar to the RY 31-S2 version, only differing for two foldings in the front crosspiece and behind the seat.
FRONT BRAKES
They are optional for the KF classes where they are admitted by regulation. The discs are 150, available in steel, while the control is manual, on the steering wheel. Necessary when passing, they are not to be passed up in the competitive arena.
CHASSIS
The three available bodies are different due to some technical specifications and the diameter of the pipe. Common among all models is the superior construction technology and quality, while from the productivity point of view, each version although having specific prerogatives, always offers excellent versatility.
EQUIPMENT
Standard equipment includes the magnesium rims with 6 anchor points, the 50x2x1040 axle, the large spindles in the front and the components (flanges, disc carrier and crown carrier) in aluminium along with the 4th removable bar next to the seat and the new Freeline pods (complete with rear bumpers) that are lighter by about 1.3 kg.
REAR BRAKE
The system has extremely high efficiency standards. It is hydraulic with a 200 “W” disk and callipers mounted on the front of them. The disk can also be requested in steel or cast iron: along with braking efficiency, the cast iron version allows for better modulation when braking and optimizes the operational temperature.
KZ / SHIFTER RACING LINE // CRY 30-S2 / CRY 31-S2 / CRX 32-S2
Also in 2010, three models will be available for the KZ and Shifter categories: the CRY 30-S2, CRY 31-S2 and CRX 32-S2. The devolpment work has particularly focused on the CRX 32-S2 model, optimizing some specifics of the frame and the optionals, which has lead to excellent results.
Instead, the spindle “C” dimensions have been reduced in all the range, where a more functional eccentric bushing system with a 4mm screw has been mount, in order to ease the camber and caster adjustments. Moreover, the reinforcements on the rear bearing cases have been removed, so to guarantee the chassis a better fluency. In the end, a new support of the seat has been introduced on the right part in order to improve the balance of the chassis and the place for the engines.
From the production point of view, it must be underlined the excellent quality control that Birel chassis have to face during each working phase, so much that even the racing division races with standard karts. From the technical point of view, the RY 30-S2 model is created with 30mm tubes and it is characterized by a front axle design with the spindle “C” anchored to the front crosspiece and a sole torsion bar.
It is very versatile and suitable for every kind of category, resulting very “free” and “fluent”. The RY 31-S2 model has the frame metal struts in 30mm tubes, whereas the crosspieces are made with 32mm
tubes. The “C” of the spindles are anchored at the bigger torsion bar height, where the metal struts join the front crosspiece. There are two torsion bars: the bigger one acts on the front axle behaviour and the smaller one increases the rear axle stability. This model offers a slightly higher grip compared to the 30mm tubes version, whereas for less rubberized and slippery tracks, a better feeling can be found with the RX 32-S2 model, which has a frame completely created with 32mm tubes.
The design is very similar to the RY 31-S2 version, only differing for two foldings in the front crosspiece and behind the seat.
FRONT BRAKES
Discs 150 “W” available in steel or cast iron and high technology blue coloured callipers. The front end inclination can be stabilized according to the driver’s preference using a brake transfer case.
CHASSIS
The three available bodies are different due to some technical specifications and the diameter of the pipe. Common among all models is the superior construction technology and quality, while from the productivity point of view, each version although having specific prerogatives, always offers excellent versatility.
EQUIPMENT
Standard equipment includes the magnesium rims with 6 anchor points, the 50x2x1040F axle, the large spindles in the front and the components (flanges, disc carrier and crown carrier) in aluminium along with the 4th removable bar next to the seat and the new Freeline pods (complete with rear bumpers)
that are lighter by about 1.3 kg.
REAR BRAKE
The system has extremely high efficiency standards. It is hydraulic with a 200 “W” disk and callipers mounted on the front of them. The disk can also be requested in steel or cast iron: along with braking efficiency, the cast iron version allows for better modulation when braking and optimizes the operational temperature.
BASIC SET UP
Apart from the tires and engine sizes used, the Birel technicians have identified a fairly versatile starting set up that can be used as a foundation before making changes to the chassis based on its driving characteristics and track conditions.
These standard adjustments call for 2mm of convergence opened in front, 5 mm of cambering open underneath and the caster neutral at zero; the 1040 “F” axle; the front bar and the 4th pipe anchored; the front carriage with two internal weights and the posterior one at 139.8 mm.
Finally, the seat is positioned with the standard measure of 124 cm between the back and front cross beam and 22 cm between the back and the axle.
The accessories (hubs, axle flanges and disc-holder) are meant to be in aluminium. With that in mind, once action is taken on the various adjustments allowed, whether on the front or rear end, it is best to remember to do only a few operations at a time.
Obviously, besides the adjustments, the behaviour of the chassis can also be modified by the accessories. For example, using magnesium components, the “fluidity” can be optimized when the track becomes “rubberized” during the course of the event and the grip increases.
THE OPTIONAL
There are some options common to the entire line for personalizing the kart, basing on the specific needs of each class and each driver.
For example it is possible to use all the magnesium Freeline components for the rear axle: hubs, flanges, brake disc carrier and crown carrier. This option guarantees a lighter weight compared to the standard components (in aluminium) of about 1,5 Kg as well as improving the fluency.
Front hubs are also available in magnesium. It will also be possible to personalize the brake system by choosing the material for the brake disc (or discs if there are also front brakes mounted) between steel and cast iron.
The first offers strong and decisive braking while cast iron allows for better modulation of the brake, also optimizing the operating temperature.
The effectiveness of both is very similar, therefore the choice is linked to the feeling that the driver has with one solution or the other.
In the end, the Freeline seat by Tillet and the new pedal-key machined in a sole piece, with the refined design for the young drivers, are available. |
