There is more to choosing an ATV tyre than just the size required. ATV tyres are made and tested to work under certain criteria and limitations and the marking found on the sidewall of the tyre, all help choose the correct tyre for the application.
Maximum Inflation Pressures show what the maximum pressure that should be used to 'seat the beads' of the tyres onto the rim. ATV tyres are notoriously difficult to fit and it is tempting to inflate the tyre pressure far beyond the maximum pressure marked on the sidewall. This can cause premature failure of the structure of the tyre and is something that should be avoided at all costs. The use of the correct tyre lubricant and fitting equipment is always recommended to ensure the safe operation and continued reliability of the tyre.
Operating Pressure shows what the optimal tyre pressure is to use in the tyre. If the tyre has a load speed index, the operating pressure is where the maximum load and speed are achieved. Inflating the tyre beyond the recommended operating pressure will not increase the carrying capacity or performance of the tyre.
Load Index is the limit of weight that the tyre can safely carry at the recommended operating pressure. ATV Tyre manufacturers design the tyres to operate within certain weight parameters. Once the tyre has passed the tests, it is awarded a load rating. It is essential that the correct load rating is used for ATV tyres. Most all terrain vehicles used around the farm are worked hard and fitting a tyre that doesn't meet the requirements of the conditions can lead to premature wear, tyre damage or failure. Load indices are usually denoted by a number. The number itself is not the actual weight carried but represents the maximum weight that the tyre has been designed and tested for. Most tyres have a load index between 0 (45kg's) and 90 (600kg's). For more information on the ATV tyre load index, please visit our load index chart page.
Speed Rating is the maximum speed that the tyre has been designed to operate at. As with the load index, the speed rating is an important part of any tyre purchase. Ensuring you have the correct tyre for the job means better operation, reduced downtime and associated costs and increased overall value. ATV tyre speed indices are usually shown as a letter ranging from C (37mph) to N (87mph).
Some ATV tyres may not have any load speed index marked on the sidewall, but most e-marked tyres will show the load speed index. The load speed index is usually clearly marked on at least one of the sidewalls of the tyres.
Ply Ratings can be quite confusing in modern times and used to be the standard way to represent the overall strength of the tyre. Ply rating used to show how many plies of rubber that were used to make up the construction of the tyre. For example, if a tyre had a 6ply rating, it would be made up of 6 plies (layers) of rubber. Modern advances in all terrain vehicle tyre technology have lead to other materials than rubber being used and construction methods increasing the strength of the tyre. The PLY rating is less commonly used to convey the number of plies and is now more relevant in showing the strength of the tyre AS IF it had that number of plies of rubber. ATV tyre ply rating is still useful in assessing the overall strength and puncture resistance of the tyre.
E-Marks show the specific number allocated to the tyre, that have been allocated for use by the EU. The 'E mark' or 'e number' shows that the tyre has been manufactured to a specific criteria and recorded by the EU for use in the EU. All tyres used on PLG registered vehicles including All terrain vehicles must have e marked tyres to be classed as roadworthy / legal. E marks are also a requirement to pass an MOT test in the UK for PLG registered vehicles.