Off The Road (OTR) tires are for trucks or large vehicles that usually move through difficult terrain. Without these tires, most trucks wouldn’t be able to make it to the other side. The quality and validation of OTR tires are overlooked by The International Standard Organisation (ISO), European Tyre and Rim Technical Organisation (ETRTO), Tire and Rim Association (TRA), and the Japan Automobile Tires Manufacturers (JATMA). All of these institutes have validated and designated the TRA as an international standard for OTR tyre manufacturing.
According to TRA, the four different types of OTR tires are as follows:
· Compactor (C)
· Grader (G)
· Earthmoving (E)
· Loader & Bulldozer (L)
OTR tyre tread thicknesses & patterns
The choice of the type of OTR tyre being used depends on the terrain characteristics and the weight that the truck has to pull. Tread depth or tread thickness and tread pattern are two other factors that help decide which type of OTR tyre to choose.
Tread thickness and tread pattern are usually associated with the flotation and smooth running of trucks even on uneven and rocky terrain. The type of thickness and pattern being used for an OTR tyre also determines its ability to resist cuts, heat, and wear.
The most commonly used tread thicknesses are:
· The regular or standard depth for OTR tires
· Deep which is 150% thicker than a regular OTR tyre
· Very deep which is 250% thicker than a regular OTR tyre
The TRA has assigned six different numbers to OTR tires. These numbers indicate the tread pattern and tread thickness that the OTR is manufactured with. Every number assigned to these tires is different based on different use cases.
Here are the different tread depths of OTR tires and their indicating numbers.
1. A ribbed tyre with a regular thickness
2. Traction tyre with a regular tread thickness
3. Rock pattern with a regular tread thickness
4. Rock pattern with a deep tread thickness
5. Rock pattern with a very deep tread thickness
6. A smooth tyre with a very deep thickness
The different types of OTR tires use different patterns and thicknesses based on the required traction and the track that they will be used for.