TWA is an abbreviation with many different meanings. Some of them are well-known, and others only are known by a small number of insiders. The latter definitely applies to the Tire and Wheel Assembly, a product – or rather a solution – that is a crucial element for any car manufacturer. In 2019, approximately 92 million motor and electric vehicles were produced worldwide. Let’s presume these are regular cars with four wheels; this means almost 400 million rims and tires were needed in one single year.
Just-in-time and Just-in-sequence delivery
Most car manufacturers rely on specialist companies to put a Tire and Wheel Assembly together and deliver it at precisely the right time or sequence (called Just-in-Time (JIT) or Just-in-Sequence (JIS)) in order for the TWA to be mounted immediately. That way, there is no need for huge stock TWAs. All the manufacturers need to do it to mount them, and the new car is good to go.
Components of a Tire and Wheel Assembly
Let’s have a closer look at a TWA. What do you need? First of all, there is the tire, generally made of synthetic or natural rubber. Next, you have the rim, usually made of pressed steel or cast aluminium. Add a valve to inflate the tyre and put some balancing weights, and you have your TWA.
How is a TWA fit
Once we have all these ingredients, we need a process to combine them all. At Eurofit, we distinguish between three processes: basic, intermediate, and high level, depending on the type of TWA or customer requirements.
- In the basic process, we mount the valve, lubricate the rim and tire, fit the tire to the rim and then add the balancing weights.
- In the intermediate process, we follow the same steps but add matching, bead seat optimisation, low-speed tire uniformity measurement of the TWA and visual inspection.
- When it comes to the high-level process, we again add important steps, focused on measuring all kinds of variables that contribute to a smooth ride. The process also helps to decrease vibrations in the car. One example is high-speed tire uniformity control (at about 120 km/h) at the level of radial, tangential and lateral harmonics.
Delivering high-quality TWAs requires experts and the most capable machines, as well as an eye for innovation. That is why we invest heavily in optimising processes on a daily basis in order to deliver ‘the perfect TWA’.