tyre testing at continental's contidrom
putting the rubber to the road
Think That Tyres Are Just, Well, Tyres? Think Again. Andy Enright Visits Continental Tyres' Contridrom Test Track In Germany To See The Lengths Manufacturers Now Go To In Getting Their Rubber Right
They come fitted to the wheels of your car, they're made of rubber, they wear out, you buy a new set. That's about the scale of the involvement that the average motorist has with their tyres. The advanced technology and painstaking testing that lies behind every set that makes it to market is a mystery to most of the people who use them and few could even imagine the level of development work that the tyre industry's major players carry out behind the scenes. The fact that tyres work, is enough for the majority of motorists but to get an idea of just why it is that they work so well, we took a trip to Continental's Contidrom tyre testing facility Just outside Hanover in northern Germany.
The Contidrom is part of a worldwide network of facilities that Continental use to develop and hone their products. The sites are spread far and wide so that, at any given time of year, the company's engineers always have access to the full range of weather conditions to put tyres through their paces. The Contidrom is Continental's main proving ground for tyre testing in Europe, although they also operate a winter testing facility in Arvidsjur, Northern Sweden. In addition, the company utilise further locations at Ivalo in Finland and Idiada in Spain, while also testing regularly in the Alps and at Germany's Nurburgring. Further to this, Continental own the huge Uvalde proving ground in the Texas desert that gives the option of summer testing in the European winter and they can access facilities at Wanaka in New Zealand when the need arises for winter testing during the European summer. There are various other locations employed by the globetrotting engineers too, including MIRA near Coventry in the UK, all helping to ensure that Continental products are up to the demands placed on them by customers.
Tucked away in a rather inauspicious location 35km northeast of Hanover, you could easily drive right past and never know the Contidrom was there. A small sign on an unremarkable suburban street points you down a long single lane road. At the end, a set of gates in the high wire fence slide open. You pass through, crest a small hill and there it is stretching out in front of you like a huge automotive theme park. The Contidrom opened in 1967 and a process of continual updating and improvement over the years has rendered it Continental's most modern testing facility. It serves as a model of alterations made to other proving grounds around the world so the facilities there are pretty-much state of the art.
The Contidrom is comprised of a range of tracks, testing areas, workshops and offices. Its time is split between Contenental themselves, leading car manufacturers, universities, journalists carrying out consumer tyre tests and the emergency services who conduct driver training on site. The scale of the facility is highly impressive and when you think that globally there are numerous other locations like this dedicated to research and development work on tyres, you start to appreciate that there's more to those rubber rings on the wheels of your car than meets the eye.
The total area of the Contidrom is 395 acres and the various test tracks are laid out within that. They range from wet and dry handling circuits to a high-speed bowl and various areas designed to test the grip, braking, wear and acoustic performance of tyres. The testing carried out on the site is divided up into subjective and objective. The subjective tests involve drivers evaluating the performance of a vehicle and its tyres on the tracks while the objective tests are carried out in controlled conditions with specialist equipment used to record accurate data on the vehicle's performance. Both types of data are then used in evaluating the tyres and the vehicles they're fitted to, ultimately leading to improved products and new technologies.
In the objective testing, vehicles are typically fitted to a rail system which controls their speed and direction. This set-up is used by Continental engineers to test a tyre's response under hard braking in wet and dry conditions or to measure its aquaplaning performance. Sensors are employed to measure speed and stopping distances with the guide rail ensuring that the car is always braking on the same surface so results can be accurately compared. In addition, there are also various acoustic tracks where different types of asphalt can be driven over and microphones measure the levels of noise that are being transmitted through the tyres into the cab.
The objective testing is largely white coat and clipboard stuff but the Contidrom also has facilities where the test drivers can push cars and tyres to their limits. Much of the facility is ringed by a 2.8km banked oval which is used for high speed stability and braking tests. The banking at either end of the track is steep enough to make clambering up it on foot virtually impossible and the compression forces when you drive through the middle of it at 150mph are something to be experienced. Turn to look out of the driver's side window and all you'll see is sky, but you're being pushed so hard into your seat that which direction down is becomes a matter of some uncertainty.
Vehicles are routinely tested beyond their limits at the Contidrom and one test for 'critical inflation pressure' sounded particularly daunting. Tyres are driven at increasingly high speeds with increasingly high tyre inflation pressures to discover at what point tyre and rim will part company. It sounds a dangerous exercise but it's all carried out under controlled conditions in the name of safety so that risks to the public can be minimised.
Water on the road is usually a prompt to slow down but the Contidrom's wet handling circuit offers scope for drivers to push tyres to the edge of their wet weather grip. A system of sprinklers creates a film of water across the surface of the 1.9km circuit so that you're basically driving on a shallow puddle. The amount of grip that modern cars with modern tyres can eek out here is remarkable but the speeds at which the twisting track can be negotiated are dramatically reduced by the presence of all that water. A similar system of sprinklers is used to wet the 'small circle', where cars lap a tight ring of tarmac with treacherously slippery cobblestones at its centre. The idea is to gradually increase the car's speed over a number of laps with a sensor hidden in the tarmac timing each one to determine grip level of the tyres. The other option is to blast around the circle winding on armfuls of oversteer trying to maintain a balanced slide, this practice tells you little about the dynamic abilities of the tyres but it's great fun.
A visit to the Contidrom will be a real eye-opener for anyone who has never given much thought to the work that goes into designing and producing the tyres on their car. It can only really instil confidence in the rubber on your vehicle when you appreciate the time, investment and technology behind the production of modern tyres. The work carried out at the Contidrom is central to the development of all Continental products and although experience of visiting the facility was an extremely enjoyable one, what you really take away is the scale of the operation and its dedication to producing world class tyres.