Recent rule changes by Historic Kart race series promoters RetroRacer’s have brought their flagship Formula A class into line with the similar F100 Spirit of the 90’s series.
In future competitors in the RetroRacer formula A series will be able to use either the current Mojo D2 / Vega W5 rubber or with immediate effect Komet K1H and Komet K1w tyres.
Further to this the weight limit of the RetroRacer pre 95 class will fall into line with F100 at 148kg. The weight of the 2 series pre-2000 classes already being the same.
A spokesman for RetroRacer said “We want to give everybody the chance to compete whenever and wherever suits them. It seemed a no brainer to make it easier to cross between the two series which had very similar regulations anyway. It would be great for F100 competitors to experience the atmosphere of an all historic kart meeting such as we organise and we felt that it was necessary to facilitate this.
Now competitors can cross between the two series without even having to do as much as move a block of lead.”
In the mid-1970s a well known and successful Italian industrialist produced a tyre for 100cc karts called the Four Star. I believe I am correct in saying that the fronts were only made available to his racing son and I know that I am right in saying that a pair of Four Star rears in those days cost about the same as a full set of tyres may cost today! However, these tyres were a must have performance aid and those who needed them managed to afford them and were glad to do so. Their life expectancy was somewhere in the region of 40 laps, but the grip level was something that most people had never experienced before. The name of this successful industrialist was Rovelli, his son Felice won the World Championships in 1976 (using the Four Star tyres) and 1977. The family also owned the mighty Sirio brand of kart engines, a name that was later absorbed within the IAME range of products. Four Star tyres were also sometimes known as Sirio. These tyres were the forerunners of the Vega brand which started in production in 1984 at Lainate just north of Milan in the northern industrial heartland of Italy. Sergio Mantese was a tyre technology expert working for Pirelli and was excited by the prospect of manufacturing his own products specifically for the karting industry. The production of tyres cannot be compared to the engineered components or finished items from any other industry.
To draw a comparison to the manufacture of pasta might have some parallels but it must not detract from the complexity of producing a tyre that has the required level of quality to be used for racing at the height of competition. Vega moved to their existing factory at Saronno ten years ago. Drawing on their extensive experience they were able to purpose build the production areas to suit their extraordinary requirements. Producing kart tyres is not an industry that has many members, I hazard a guess at no more than ten in the world. Therefore it is not possible to go to an engineering exhibition and take your pick of the requisite machinery. For this reason Vega have their own design engineer who is responsible for the continuous development and maintenance of their plant. The first phase of the production involves the mixing of the tread compound. For every 1000kgs of tread compound there can be up to 40 ingredients, these are called prime materials. Vega have their own on-site laboratory with staff permanently confirming the consistency of these prime materials. As each prime material is chosen it is measured to the nearest gram as part of the make up of 1000kgs of compound. The mix is then monitored for temperature and is then remixed twice more before being extruded into the finished article. The compound is measured for thickness at regular intervals and a sample is taken every 30cms.
These samples are coded and sent to the laboratory where they are checked for consistency. Despite the ingredients in tyre production being dirty, black, volatile and jam packed with toxins, the Vega factory is clean, quiet and dust free. Their air extraction, filtration and conditioning systems are not just about the modern requirements of health and safety, they are fundamental to the production of high quality kart tyres. Following the production of the compound it is then passed through a complex piece of machinery that converts it into a tread, ready to be laid up onto the tyre carcass. The tyre tread is instantly recognisable, every different compound is colour coded along its whole length and the tread depth is also controlled to 0.1mm or 4 “thou” in old money! This depth control is applied along its length as well as across the width. There are constant visual and measured quality control checks. A different rubber compound is used for the sidewalls and for the laminated textile carcass. The bead of the tyre is made from rolling plated steel wires and embedding them in rubber as they are turned, again using a unique machine. The bead is eventually fitted over the edge of the sidewall material and a final piece of rubber compound is added to complete the airtight seal where the tyre meets the wheel rim. The extruded tread is cut using an ultrasonic blade to produce such an accurate cut that the join cannot be found once the tyre assembly is complete. The ultrasonic blade has to be cooled by an air jet to stop the two pieces of rubber fusing back together immediately. The various components of the tyre are assembled with the help of lasers to ensure that any risk of a misalignment is eliminated.
The assembled tyre is then taken through into the vulcanising shop where nine vulcanising machines work round the clock. They are gas heated and require some hours to reach operating temperatures, each has its own air extraction system. Two men operate the nine machines. It is at the point of vulcanisation that the tyre takes on its final form. All writing on the sidewalls, the “Vega” badge and any specialist badge such as “JAG” or “GB” is also added at vulcanisation. The tread on wet tyres is moulded at this time as well. Vulcanising takes 10 to 12 minutes per tyre and as such has to be the most time consuming element of the production of each single tyre. The tyres are then racked to cool before going for final quality inspection, wrapping, boxing, storage and despatch. Paulo Mantese, son of the founder, who showed us round the factory, was very candid about the production of tyres. To quote his own words “a tyre is a living thing”. The rubber is a natural product and can therefore be affected by heat, cold, humidity and light. There is a 2% quality failure rate on the production of Vega tyres and this is believed to be one of the lowest wastage rates in the world and something which all members of staff are constantly striving to reduce. Many of these quality rejects are only cosmetic damage that would not affect the performance of the tyre, however they are never allowed out onto the open market. Vega has another production facility at Ales in Southern France. Vega France do not produce any tyre compound, it is all produced at the main factory at Saronno in Italy. Vega France produces most of the economy class tyres and those for the French market.
The factory in France has lower running costs and is well placed to service the domestic French market. Vega currently produce 600,000 tyres a year, this is slightly under maximum capacity. Using their existing plant and machinery it would be possible to increase production up to a maximum of 850,000 with the simple addition of a few more personnel. Their world markets are developing. Their home market, Italy, is stable at approximately 30% of production. The rest of Europe, predominantly France, Germany and the UK accounts for another 30%. The rest of the world takes care of the balance of 40%. A significant number of tyres go to Australia and New Zealand while the biggest developing market is America. It seems that any requirement for a hike in production is likely to be driven by a greater demand from the USA. Interestingly, wet tyres only form 5% of the total production. I would have been way off beam if you had asked me that one! Vega accept that the majority of their sales come from the National classes racing all over the world, however they do consider the need to be at the top of International competition to be essential to the future of the company. It is the evolution and the need to be abreast of the very latest technology that will keep them at the top of the game alongside the other big players in this very specialised niche industry. Paulo’s brother Stefano is heavily involved with the testing of tyres and spends much of his time at circuits with the world’s top drivers and teams. There is a constant need to progress and evolve the product range. The future TAG classes will have more torque and potentially more horsepower than the existing 100cc classes. Vega sees this as another potentially evolutionary change to the requirements of the tyre. They talk about elasticity of the carcass, mechanical grip and lateral grip.
The ways in which engines perform clearly have a major effect on the type of tyre production chosen for each power level. Although I have always said that each class should have a tyre that has the correct window of grip level to suit its power and weight, this statement, while correct, is only scratching the surface of the complexity of the ideal production for each specific purpose. Vega are producing the tyres for the ICA and JICA classes at European and World Championship level this year having won the contract from the CIK. These contracts are not won easily. It is a testament to the longterm quality and consistency of the product that has earned them this prestige. Vega has won five World Championship titles and countless National titles all over the world. Alex Zanardi is the spiritual son of Vega having won on their product when he was at the top of the karting game in the 1980s. Vega employs 50 people. In Saronno they carry out the whole tyre production process including design and development of machinery. The main laboratory is at Saronno also, as is their research and development department. Ales in France take finished material from Saronno and completes tyre assembly, vulcanisation and distribution of their production. It cannot and should not remain a secret that tyres are a living breathing thing that have a very complex construction based around a natural product, rubber. Rubber comes from trees and Vega buys their rubber from all over the world. Each tyre compound is always produced from rubber from the same source and each batch of product received at Saronno is laboratory checked for consistency against the previous delivery. The thoroughly modern production methods employed at Vega are now producing some of the best karting tyres in the world. The performance and durability of the tyres now in use here in the UK could never have been achieved ten years ago and it is no longer necessarily true that a new set of tyres will be faster than a lightly used set. My visit was a real eye opener, I hope this article has opened your eyes too to the complex world of tyres.
Dust off your pink and purple racing suit; Formula 100 ñ Spirit of the 90’s (F100 90s) is rapidly gaining popularity, and attracting a real mix of drivers, from British Champions, to novice drivers. Some big names are already taking part, keen to relive this special time in karting, with more big names currently completing kart restorations in order to compete next year.
But it also seems to have grabbed the attention of the less experienced as well, keen to see what all the hype is about. It helps that kit is inexpensive in comparison to many other formulas. The kit can be picked up on the auction sites, with complete packages including two motors, wheels, tyres and kart for less than £1000, it’s a cost effective way to go karting, with full sized grids after only it’s fourth round.
The series exclusively runs pre-year 2000 karts using 100cc direct drive, air cooled, reed or rotary valve engines and is aimed at competitors who wish to race this era of kart. All equipment is presented for racing in the same form as it would have originally been used in the 1990’s.
The emphasis is on competitive, fair, safe, enjoyable, and affordable kart racing, and to re-live this special period in kart racings’ history. No clutch, no starter motor, no battery, no radiator, no pump, no rev limiter, no gears; pure, unadulterated karting at its very best.
Oliver Scullion, series organiser spoke to Karting and said: “The best thing about F100 90s for me is the emotion I see in people’s faces when they drive one. It’s really as simple as that. That’s why I wanted to start the class. I am a 90s karter, and nothing really gets to you like a DSD or VR98. I want other people to have the opportunity to experience what I’ve been so lucky to have experience. As it’s within a competitive environment it’s not just a demo. This is the real deal, this is proper racing, on proper karts! Some of the names that have entered the class, and looking to in the future are testament to the emotion is brings out in people. If you haven’t ever tried one, give it go!”
Next race meeting will be held at the spiritual home of 90’s karting – Clay Pigeon, on Saturday 27th September.
1994 Britsh Champ and local boy Jamie Patten will be the man to beat, and Karting Legend Terry Fullerton will be there to chose his ‘F100 driver of the day’ and a present the trophies.