On the road... with Ed Foster
Dunlop tyres factory tour
How to produce almost a quarter of a million racing tyres a year…
Since 1888 when John Boyd Dunlop invented the first pneumatic tyre for his son’s tricycle, Dunlop has been producing rubber for all types of machinery.
Nowadays Dunlop is as busy as ever, and from its motor sport facility on the fringes of Birmingham it produces 230,000 tyres a year. The BMW M3 GT2 in the ALMS and LMS uses some of these, others include Dunlop Historics for many of your classic racers, and a large amount end up on tin-tops in the BTCC. That’s not to mention the tyres it makes for Moto2, motorbike endurance racing and the X Games, or the 6500 tyres it has to produce for the Dubai 24 Hours in mid-January. Dunlop is a rare ‘master of all trades’.
The challenges involved in supplying all these tyres are too numerous and complicated to list here. What’s more, it would be negligent of me to take up space when I could otherwise tell you about the processes and detail that go into making the tyres.
Dunlop doesn’t do official tours, but Kate Rock — PR support manager for Goodyear Dunlop Tyres UK Ltd — did say it could be persuaded. It would be worth trying — the facility is absolutely fascinating.
The first thing that strikes you as you walk round the factory is just how many people are involved in making the tyres. Over 400 staff work in manufacture and distribution for Dunlop’s motor sport arm, and many of these are at machines, physically bending each layer of rubber compound around a metal drum — or a 90-year-old woodwormridden drum if you’re making a crossply. It’s the only original machine like it in the world and it won’t be moved anytime soon as it will then have to conform to 2011 regulations. To give you an example of how labour-intensive tyre manufacture is, a single crossply for a Ford Model T takes seven hours to produce.
Because of the huge variation in Dunlop’s tyres every mixture of compound is fastidiously labelled and measured. Once this has been mixed — up to three or four times — and heated up to 80deg C, the compound is milled out and left to cool. This is only the start of a very laborious process.
It is a relatively common misconception that the compound is then poured into a mould and left to set, leaving a perfectly round and treaded tyre at the end. Nothing could be further from the truth. Not only do tyres include a raft of different materials in them — that are all applied by hand — many have different compounds across each tread. The best example of this is on a motorbike tyre. In the middle of the tread a relatively hard compound is used because when the motorbike is upright (which is most of the time) the need for excessive grip is quite low. As you move across the tyre to the outer edge the compounds can and usually do become softer, giving you more and more grip the further you tip the ‘bike over.
This works well for road ‘bikes but is taken to another level with racers. If the tyres are to be used at a track with lots of left-handers, then the left side of the tyre will be made of a harder compound, as that’s the side that will wear the most. Hence it becomes very important to fit race and road tyres the right way, and there is always a directional arrow, even on slicks.
Underneath all this is what’s known as a JLB, or a Jointless Belt Band. This is a strip of rubber that contains five threads of Aramid (a material used for bulletproof vests) alongside each other. This is peeled off like tape from a roll and applied to the bottom layers of the tyre so that it can’t expand. Ever wondered why dragsters’ tyres get larger and larger as they hammer down the quarter-mile strip? It’s because drag tyres don’t use JRB, as an ever-expanding tyre helps the machine go faster and faster. An expanding tyre on a corner would produce a very different outcome.
Once all the different layers have been added — from the inner liner, the body plies and the sidewalls to the treads — the tyre is cured at 160deg C. A rubber bladder inflates inside it, which then makes the outer edge expand into the mould, and 20 minutes later you have a finished — if very hot — tyre. As we wandered past the stacks of finished tyres I couldn’t help ask how long Dunlop Historics would keep, knowing that our MGB was sitting on three-year-old rubber. It turns out the tyres will keep for quite a long time (not necessarily three years) as long as they are wrapped in bin liners to keep the sunlight out and not stored in a workshop where electric tools emit ozone. Two things we have neglected to do with the MGB’s tyres…
The Dunlop tour was truly fascinating, and it’s well worth calling the company to try and persuade them to let you look round.
EAST PRESTON, UK
Famed car maker has changed its focus to two-wheeled transport
Any car companies have made bicycles, and many bicycle companies have gone on to make cars. Rover was the first company to build mass-produced bikes in Britain and Peugeot was the first to do the same in France.
It’s rare, however to hear of a car company that now only builds bicycles. As anyone with a passing interest in bikes will tell you, it isn’t a fast way to make money. But Cooper which made its name as an Fl constructor and stormed the world of rallying with the Mini, has done just that.
Mike Cooper son of John, is relaxed and smiling when we meet at Cooper Bicycles in West Sussex. He has gladly walked away from the difficulties of the car industry and has huge enthusiasm for the (non-motorised) two-wheeled revolution. “I cycle to work every day, which is only five miles, but I’ve lost two stone and I love it,” he tells me after a light lunch at the local pub which, thanks to heavy rain, we drive to in a 211bhp Works Mini Cooper.
“I loved bicycles when I was 12, but at 16 I started to get interested in motorbikes and then cars,” he explains. “It was only when I passed 50 that I got back on a bicycle again to keep fit. I thought ‘we could build a little bicycle business.”
Mike and his family’s enthusiasm has paid off. In 2010, after selling the Cooper name and business to BMW Cooper Bicycles made and sold 1000 bikes. This year it’s planning to build 3000, and 10,000 in 2012. It doesn’t want to move into mass production, but Cooper has big plans, including starting to build units in the UK rather than overseas. Mike wants to reignite the British bike-building industry, which has wallowed in mediocrity since the heady days of the 1940s and ’50s on the Old Kent Road, by making 50 per cent of Cooper bicycles in Britain within five years.
An ex-tuning company building a bicycle? A ridiculous concept? Not at all. The bicycle industry is a strange animal. There are manufacturers, but what they tend to do is buy a frame from China, brakes and gears from Taiwan, some wheels from somewhere else, put them together, add their name and sell it. If you’re a fast learner and understand business, it’s not rocket science.
“It’s a triangle with two wheels,” Mike agrees. “You find a good frame maker and assembling company, and it’s like a sweet shop. You arrive and say ‘I like those chain rings, those pedals, that bell, those grips’. I’ve only been in the business a year but we’ve learnt so much. Everyone is helpful. It’s not like the car industry where everyone is secretive. You can call people for advice and I read a lot of bike magazines.”
Cooper occupies a corner of the market where not many other companies operate. Its bicycles are all road racers/ city bikes and hark back to the ’60s with retro styling. All are named after famous circuits such as Zandvoort Sebring and Monza, and they are, by common consent, brilliant and competitively priced from £600-1000.
This isn’t just a result of reading reviews, as Mike would have you believe. “Of course, I’ve brought some knowledge from the car industry such as understanding rolling resistance and unsprung weight,” he says. “But the most important part on a bicycle is the bottom bracket and hub. The bits that move should be the best bits and everything else works around that.”
We visit the workshop where the bikes are assembled to look at the full range (seven models, with five more planned for this year). The whole range is leaning against a wall, with Stirling Moss’s 1954 500cc Cooper and Jackie Stewarhs Cooper F3 sitting nearby. This may be a bicycle company now, but Cooper hasn’t forgotten its roots.
Some Cooper fans have been lukewarm on the company’s move, but the cycling fraternity has welcomed it with open arms. If Mike’s first range is anything to go by, the future looks bright.