BIREL RACING LINE - KF
The three models available for the KF classes have features that are often complimentary so that, in a competitive environment, almost all teams make at least two versions available to their drivers. That is in order to find the best productivity regarding the tires used, the conditions and the configuration of the track. Let’s look at the principal features of each of the Birel KF models for the 2009 season.
RY 30-S1:
The body is made of 30 mm pipes and is characterized by a front axle design that has the “C”s of the spindles anchored to the front crossbeam. Also in the front zone there is a single torsion bar. It is especially advised for use with soft tires and on rubberized tracks. But, due to the torsion characteristics of the body, it is also very effective in the youth classes (for example the KF3) where, usually, hard tires are used. Ending up very “free”, in fact, takes the best advantage of the limited power of the engines used in these classes. The removable 4th bar next to the seat is also functional in this sense.
RY 31-S1:
The body cross-members are built with 30mm pipes while the crossbeams are 32 mm. The profile is a recalculation of the previous model R 31 with the spindle “C” anchored at the height of the largest torsion bar where the cross members meet at the front crossbeam. Also in the front there are two usable torsion bars, with the larger one acting on front end behaviour and the smaller one increasing the rear axle grip. This model is an excellent compromise for versatility, adapting itself very well to both soft and medium-hard tires. Its strong point is its excellent fluidity and the general balance between the front and rear ends.
RX 32-S1:
The body is entirely built of 32 mm diameter pipes. The design is very similar to the RY 31-S1 version with the only difference being (besides the diameter and some technical specifications of the pipe) that there are two bends in the crossbeam in front of the seat and the one behind it. This model is particularly advised when grip is needed, thus for barely rubberized tracks, low temperatures and with the use of mediumhard tires.
Novelties for 2009
Among the most significant novelties introduced with the new certifications is the new model RY 30-S1 (made with 30 mm pipes). A conventional one, it allows the driver to easily find an excellent set-up offering excellent performances for all uses: from the youth classes up to the top categories. On the other hand, models RY 31-S1 and RX 32-S2 are advanced in comparison to the previous certification. Both versions were updated, especially concerning the technical specifications of the pipe. Among the prerogatives and the equipment common to the entire line, there is the removable 4th pipe at seat height (removing it “frees” the chassis at the rear axle while more grip is guaranteed with it in place) and the new “large” front spindles with a diameter of 25 mm characterized by the possibility of varying the shaft (with material alternatives as with the axles) using a special key that is supplied with the kart. The housings used are the “FL 09- 14” (with new graphics) that maintain the aesthetic lines of the previous ones but that were optimized with their weight reduced by about 1.3 kg. Finally, on the entire line, there is an HQ exhaust support in order to facilitate mounting the rear housing and a new machined foot rest.
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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 2 mm 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 123.5 cm between the back and front cross beam and 22 cm between the back and the axle (see pag. 29). 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 based on the specific needs of each class and each driver. The most important novelty is in the possibility of using all of the magnesium Freeline components with the rear axle: hubs, flanges, brake disc holder and rim holder. This option guarantees a lighter weight compared to the standard components (in aluminium) of about 1.5 kg as well as improving the fluidity. 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 when there are also front brakes mounted) from steel or 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 pilot has with one solution or the other. And finally, the Freeline seat by Tillet will be available.
CRY 30-S1
Is advised for categories that use soft tires and for use on rubberized tracks. But it is also excellent for the youth classes that, although using medium-hard tires, require a “free” chassis due to limited engine power.
CRY 31-S1
Is advised for categories that use medium- soft tires. It is absolutely the most versatile model, adapting itself very well to all track conditions. Excellent balance is one of its strong points as is its precision when entering a curve.
CRX 32-S1
Is advised for categories that use medium- hard tires. It offers an excellent grip, also adapting itself well to more slippery tracks and to drivers who prefer a precise chassis, especially in fast curves.| CRY 30-S1 | CRY 31-S1 | CRX 32-S1 | |
| HOMOLOGATION | 25/CH/14 | 26/CH/14 | 79/CH/11 |
| FRONT STABILIZER | STANDARD | DOUBLE | DOUBLE |
| REAR STABILIZER | OPTIONAL | OPTIONAL | OPTIONAL |
| SIDE STABILIZER | 25/CH/14 | STANDARD | STANDARD |
| Ø TUBES | 30 | 30/32 | 32-(30) |
| WHEEL BASE | 1040 | 1040 | 1040 |
| REAR WIDTH | 645 | 645 | 645 |
| FRONT WIDTH | 715 | 715 | 715 |
| LENGTH | 1600 | 1600 | 1600 |
| AXLE | 50X2X1040F | 50X2X1040F | 50X2X1040F |
| BRAKING SYSTEM | HYDRAULIC CX | HYDRAULIC CX | HYDRAULIC CX |
| BRAKE POSITION | FRONT+ REAR | FRONT+ REAR | FRONT+ REAR |
| FRONT BRAKE DISC | 150X4 A/150X6 G | 150X4 A/150X6 G | 150X4 A/150X6 G |
| REAR BRAKE DISC | 200X7 A/200X9 G | 200X7 A/200X9 G | 200X7 A/200X9 G |
| TANK CAPACITY | 10 LIT CA | 10 LIT CA | 10 LIT CA |
| STEERING WHEEL | 320 MTS | 320 MTS | 320 MTS |
| DISK CARRIER | 50 HQ | 50 HQ | 50 HQ |
| CROWN CARRIER | # | # | # |
| FRONT HUBS | 75 HI TECH | 75 HI TECH | 75 HI TECH |
| REAR HUBS | 50X95 HI-TECH | 50X95 HI-TECH | 50X95 HI-TECH |
| WHEELS | DF130 + DF210 | DF130 + DF210 | DF130 + DF210 |
| PODS | CIK 09-14 | CIK 09-14 | CIK 09-14 |
