Mojo Tyres: Long lasting

Back in 2003 BRP-Rotax announced that Reifenwerk Heidenau from Dresden in Germany was cooperating to develop and make a range of tyres with demanding requirements. They were to be the perfect tyres to use for the national and international Rotax MAX Challenge (RMC) racing series, and Heidenau was the right partner to fulfil this requirement.

Consistent grip and good balanced track performance and yet maintaining reasonable rate of wear over a given number of laps, these were the key requirements for the manufacture to get perfect racing tyres. These characteristics match the RMC’s concept that stands for equality. “We pride ourselves on safety and equal performance, and that MOJO tyres help drivers in the best way possible if they later want to move into a career in motorsports”, says Helmut Voglsam, head of Rotax kart set up.
 
Together with Heidenau, BRP-Rotax developed a product- and a quality assurance process to keep their promise. The raw material for the running base is delivered by a defined supplier with a report on material analyses. Heidenau takes a sample to be analyzed in the laboratory on site from each batch to check out the supplier’s report.
 
The manufacturing process has been standardized to guarantee consistent quality, and constant production according to the market’s demand (forecasting system of the network) is one of Heidenau’s main strong points.
 
Each MOJO tyre is stored for at least 30 days to be cured, during this time 90% of the aging process is completed.
 
From the very start, all models of MOJO tyres are manufactured to the DIN EN ISO 9001 standard. As from 2011, MOJO tyres are CIK homologated and therefore free of Poly Cyclic Aromatics (PCA).
 
Each tyre its serial number in random order (barcode). The barcode on the tyre, in combination with the Rotax Event Management System (EVA), enables easy control of tyres during RMC races.
 
The company provides three types of CIK homologated MOJO tyres for dry conditions (D1, D2, and D3) and one CIK homologated tyre for wet conditions – the W2 for gearbox and non-gearbox classes.
 
A regular testing program continually evaluates tyres for consistency and performance.
HOW MOJO TYRES ARE MADE
 
At the supplier’s
After a computerized weighing process the different compound components (Polymers, carbon black, special oils without PCA oils, resins, sulphur and 15 other additives) are sent into an internal mixer. In this batch pre-stage production, the compound goes directly into a second internal mixer where the compound is finished off in 450 kg batches.
 
3 different test samples are taken from each batch and are sent immediately to the on-site lab. This 450 kg palletized tread compound is then sent to Heidenau. The compounding process is controlled digitally so as to always guarantee the same quality.
 
At Heidenau
The batches (450 kg each) from the compound supplier go to Heidenau’s Triplex extruder. The compound is transformed into a long strip with the exact shape of the running tread. This machine can process 2,500 kg/hour (three different quality tests per batch).
The running base of each specific compound then receives its permanent coloured marking line so that the type of running base can be identified throughout the various production processes.
 
The next step is the production of steel bead rings.
The calandar machine, the so called “MONSTER” is 12 m long, 7 m high and weighs 53 tons. This machine coats the cord material on both sides with a special carcass-rubber compound (700 m/hour).
 
Heidenau uses several semi-automatic coiling machines and they can produce 18 tyres/hour/machine. Laser beams are used for precise positioning of the single layers.
Tyres are easily identified according to the barcode on each tyre.
On the site, after this production phase, these tyres are called “cigars” due to their shape and the way they have been wrapped.
 
They are then sent to the vulcanization line, where up to 20 moulds of different tyre models can be handled. Each tyre vulcanization cycle requires more than 15 minutes of vulcanization at approximately 15 bar with temperature above 150°C and after a 13 minute cool-down cycle.
 
After cooling, each single tyre is inspected during the quality control process.
 
After printing the MOJO logo on each tyre, the tyre passes a shrinking tunnel for its nylon protection wrapping. Afterwards, before packing, each tyre barcode is scanned.
 
Each MOJO tyre is stored for at least 30 days for curing. During this time 90% of the aging process is completed. This is a very important factor in how tyres are stored.
 
It takes 27:18.3 minutes to produce 1 MOJO tyre.