Tread Life / Tread Wear
There are well over 25 different variables that can affect tread life: the tread compound, the alignment of the tyre, the road texture, the tread pattern, idiosyncrasies in an individual’s driving style, and more.
This high level of variability can make it extremely difficult to make objective comparisons and observations in a testing environment.
Testing for Tread Wear
On-vehicle tread wear testing is very challenging and expensive to conduct.
The shortest on-vehicle treadwear tests require 7,200 miles of travel, while other protocols require 150,000 miles or more.
Additionally, on-vehicle tests require a series of specific procedures to ensure repeatability. This can include specific courses, frequent checks of vehicle alignment and loading, and close monitoring of tyre inflation pressure.
Indoor tread wear testing in a controlled laboratory environment is usually a more accessible option due to cost and the ability to limit more variables.
An important factor to consider when it comes to treadwear is footprint pressure distribution.
Footprint pressure distribution assessments can be conducted in a controlled laboratory environment to measure wear throughout a tyre tread before and after tread wear testing.
Uneven distribution of footprint pressure can lead to abnormal and irregular wear, which can cause problems and shortens the lifespan of the tyre.
For example, areas with low contact pressure may experience faster wear due to more scraping and sliding against the road surface.
Tread Attributes Benefiting Long Tread Life
A tyre engineer seeking to increase the lifespan of a tyre tread may;
- Maximise the contact area and minimise void areas.
- Reduce the size and quantity of circumferential grooves and slots.
- Maximise tie bars to minimise squirm and deformations, especially in the shoulder ribs.
- Maximise tread depth.
This information has been reproduced with the kind permission of Smithers
Smithers is an independent, third-party testing and consulting company with a history in the tyre industry starting back in 1925. Their team has many years of experience in the tyre and rubber industries and have created this information as an educational resource on the general science behind tread development.
As an organisation, Smithers do not actively develop tyre treads for commercial use in the market.
Tread design is a complex, highly specialised activity that must take into account each manufacturer’s design and development goals.
© SMITHERS, 2021