Metzeler Racetec RR: New racing supersport tyres unveiled

Metzeler has released details of a new racing supersport tyre – the Metzeler Racetec RR – at EICMA. Here’s what the press release has to say…

RACETEC™ RR, the successor of RACETEC INTERACT™, is the new METZELER tyre available in K1, K2 and K3 compounds and is characterised by high grip in all conditions, with precision, excellent stability and consistent performance.

The origins: the Road Racing world

RACETEC™ RR is the evolution of RACETEC INTERACT™, produced in line with the development of new bikes, and comes directly from the experience of METZELER in Road Racing competition in which the brand of the elephant has been participating with good results for many years. In 2014, riders supported by METZELER stood on the podium 39 times with 16 wins in the major road races. With substantial efforts in these activities, METZELER was able to completely renew its sporty range of tyres and, during 2013, developed and launched SPORTEC™ M7 RR and now, exactly one year later, has completed this renovation project with the new Racing Supersport RACETEC™ RR.

In particular, RACETEC™ RR has been designed and tested in major competitions such as the North West 200, Metzeler Ulster Grand Prix, Southern 100 and especially the Isle of Man TT, where it won the Supersport class by equipping the Triumph Daytona of Gary Johnson. These races do not take place on track, but on roads that are open to the public throughout the year and in which you can find all the situations that each rider encounters in everyday riding. For this reason these events were chosen by METZELER as a test and development ground.

The origins of RACETEC™ RR are clear from its name: RACETEC™ identifies the METZELER range of products dedicated to sport while RR, defined as Road Racing, testifies to the context in which this project was born.

Who is RACETEC™ RR aimed at?

RACETEC™ RR is dedicated to racers of all levels plus trackday riders who use the circuit for their hobby.

In the K3 compound option specifically, the RACETEC™ RR is designed for all owners of supersport and naked bikes who enjoy a sporty riding style and who want the ultimate grip even on the road, looking for excitement and a high performance level.

The features and the benefits of the new RACETEC™ RR

RACETEC™ RR includes the technologies, materials, advanced processes and know-how achieved by METZELER tyres in recent years, bringing a new level of performance. RACETEC™ RR offers new profiles, structural materials, compounds and tread pattern.

Road Racing is one of the most difficult and challenging competitions due to the combination of factors such as the long race distances, , high average speeds, elevation and temperature changes along with the variety of road surfaces. RACETEC™ RR is designed to meet all these different situations which may be encountered in one race, providing unmatched mileage and consistency, combined with a great versatility.

The main benefits of RACETEC™ RR are:

• Grip in all conditions, both on road and on track thanks to the versatility of the compounds

• Precision and stability, useful features both in during ‘lean’ as well as on the straight due to the ability of the tyre to absorb the roughness of the asphalt

• Performance consistency throughout the life of the tyre

In particular, the rear tyre of RACETEC™ RR is bi-compound and is able to offer excellent grip in cornering together with great stability at high speeds.

Unlike its predecessor, all the sizes and compounds of RACETEC™ RR have the speed index W in brackets, which allows these tyres to be used on roads open to the public and not just on circuit.

Road Racing events are usually high mileage, up to 240 km in total, on average more than twice the distance taking place on circuits. For this reason, the duration and the ability to preserve the integrity and performance of the tyre proves to be a key factor for victory. RACETEC™ RR is the winner in this area due to the characteristics of the compounds and tread design.

The compounds

All the compound specifications used in the RACETEC™ RR are characterised by a high abrasion resistance due to the equal dispersion of ingredients, obtained by a patented mixing process.

To face with the changing conditions that may be encountered during the same race, METZELER has greatly expanded the versatility of the compounds.

If for example the K2 version of RACETEC INTERACT™ was intended to be used with difficult road conditions and low temperatures, now the new K2 compound of the RACETEC™ RR offers high performance even at increased temperatures and on  more smooth asphalt. Similarly, the K1 compound of RACETEC™ RR can now also be used in conditions of lower temperatures and with a more aggressive road surface.

To achieve this goal, work was focused mainly on the formulas of the compounds, balancing polymers, resins and reinforcing fillers to generate different properties.

RACETEC™ RR is available in K1, K2 and K3 compounds. Motorcyclists can easily distinguish one compound from the other thanks to the labels on the side and the coloured stripes on the tread.

• K1 – SOFT in soft compound. It has a label on the side with K1 written in blue and a blue stripe on the tread

• K2 – MEDIUM in a compound of medium hardness. It has a label on the side with K2 written in green and a green stripe on the tread

• K3 – HARD is the harder compound. It is distinguished by a label on the side with K3 written in yellow and a yellow stripe on the tread

With regards to the rear solutions, the criteria for application is based on the severity of the asphalt, on the external temperatures and on the duration of the performance required.

For example, hot asphalt loses some of its natural mechanical grip becoming smoother and more slippery. In these conditions a soft compound (such as K1) is necessary, as it can penetrate the asphalt surface as much as possible.

Cold tarmac, on the other hand, tends to be more aggressive and rougher, offering more mechanical grip which, while on the one hand is an advantage, on the other hand can cause the tyre to rip and tear, which therefore needs a compound with more mechanical resistance (such as K2).

For the front solutions the criteria for which to use is based not only on outdoor temperature and track layout (many bends or long straights, etc.) but also on the rider’s aggressiveness/riding style which affects the front tyre.

In general, with regards to weather conditions, when the track temperature increases, the compound tends to lose its compactness and rigidity. This behaviour can cause movement problems in the ‘leaning’ stage. A more rigid compound such as K2 can reduce this effect.

Conversely, when the track is cold, the compound tends to become more rigid and this leads to a penalisation in regard to grip and stability while braking. In these conditions it is better to use a soft compound such as K1.

The K3 compound is dedicated to non-competitive use and can be used at any temperature, in any condition or abrasiveness of the asphalt, and is able to offer a significantly greater mileage.

Another distinctive feature of Road Racing is the presence of very long straights, where the bikes keep speeds above 300 kph for a long time. This situation typically generates a warming of the central section of the tyre that is in contact with the ground and a cooling on the sides. As a result, when entering the curve after a straight, the side may not be in the correct operating temperature and then be able to ensure the necessary grip. RACETEC™ RR uses a bi-compound rear solution with a “Cap and Base” structure in which the centre compound supports the lateral compound positioning in the substrate of the tread. While generating less heat, this centre compound is able to distribute it in the substrate and then heating the compound present on the sides.

With this solution, the longer the straight, the more time the central compound will be in contact, consequently warming the side sections, reaching and maintaining the operating temperature and ensuring perfect grip when dropping into the turn.

The tread pattern

The layout of the central longitudinal grooves is designed to have a compact tread in the central section to optimise straight line stability.

The position of the transverse grooves provides cornering grip in all road conditions while minimising the effects of wear.

The structure and the profiles

Stability is a key factor in road races. High speed straights trigger vibration through the bike which can affect performance.

The innovative carcass material used in the structure of the RACETEC™ RR elevates its lateral stiffness to minimize these problems.

In the case of a road circuit, its peculiarities represented by manholes, repair patches and jumps etc, can also create a sudden loss of adhesion.

The profiles of the crown and sides have been designed to absorb roughness and, at the same time, dampen the deformation of the impact without generating vibration.

The sizes

RACETEC™ RRwill be available at all METZELER retailers from January 2015 in the following sizes and compounds:

Front:

120/70 ZR 17 M/C (58W) TL K1

120/70 ZR 17 M/C (58W) TL K2

120/70 ZR 17 M/C (58W) TL K3

Rear:

160/60 ZR 17 M/C (69W) TL K2

160/60 ZR 17 M/C (69W) TL K3

180/55 ZR 17 M/C (73W) TL K2

180/55 ZR 17 M/C (73W) TL K3

180/60 ZR 17 M/C (75W) TL K1

180/60 ZR 17 M/C (75W) TL K2

190/50 ZR 17 M/C (73W) TL K3

190/55 ZR 17 M/C (75W) TL K3

200/55 ZR 17 M/C (78W) TL K1

200/55 ZR 17 M/C (78W) TL K2