The standard test is a marathon event in itself: the tyres run in the test rig for over a month – up to 1,000 hours to be more precise – at a speed of 75 mph (120 km/h).
A large number of drum test rigs conduct endurance testing on truck tyres in a variety of test positions. There are also high-speed test rigs for testing car tyres at speeds as high as around 250 mph (400 km/h). Further test machines capable of applying high loads are available for testing truck tyres and special agricultural and industrial tyres. Endurance testing doesn’t look at how a tyre wears but what it can actually withstand: When and why does it reach the limit of its structural endurance? In addition to high-speed testing, there are also burst, bead unseating and plunger tests, which are carried out to ensure and document compliance with all regulatory requirements. On top of this, internal testing beyond the limits of structural endurance is also routinely carried out.
The Endurance Testing department
Endurance Testing is one of the largest test departments within the R&D arm of Continental Tyres. This is where prototypes for new tyre developments as well as random samples from ongoing production are taken for endurance testing. This involves a preliminary inspection of the tyre before it is fitted onto a special wheel rim. The tyre is conditioned, i.e. pumped up to the required test pressure and brought up to temperature, before being mounted on the test rig for testing at the desired load and speed. The tyre is regularly inspected over the course of the test run, after which it is sent to the internal analysis group where it is not only cut open, but also undergoes X-ray or CT scanning. The investigations shed light on where the tyre failed structurally and why.
Endurance Testing is one of the largest test departments within the R&D arm of Continental Tyres.
The high-speed tests are of particular interest for car and van tyres. These involve testing the tyres under conditions that comfortably exceed their speed rating symbol in order to ensure that the tyre is fit for the market. The test results are evaluated by the tyre analysis specialists and fed back into the tyre development process.
The findings from endurance testing provide vital guidance in product development, helping to make sure that work is progressing in the right direction when creating future tyre models. Quality management testing for current models accounts for around 25% to 30% of the test runs. Most test jobs originate from product and platform development and mainly involve original equipment tyres and tyres for the replacement market.