How do I understand all the markings on the tyre sidewall?
Firstly there are several Tyre Size Markings. Predominately today we use the Radial Markings, for example, 480/70 R 34, this indicates 480 is the Nominal section width (in mm), 85 is the Aspect ratio H/SW (in %), R is Radial construction, 24 is the Nominal rim diameter (in inches).
What is important about a tyres Static Loaded Radius and why is it essential to correctly match dual wheels?
The SLR or Static Loaded Radius of the tyre is the distance from wheel axle centre line to the supporting tread surface at a given load and pressure in a static condition.
When ordering your dual wheels for your tractor it is important to match the SLR of the wheel of the tractor to the Dual Wheel being fitted. When fitted, under no load the narrower tyre may look as if the radius is smaller than that of the wider tyre. However, when the tyre is in work the wider tyre has a greater deflection than the narrower tyre and will, therefore, apply an even distribution of load.
What is the load rating of the tyre on my machine?
The load rating of any tyre is indicated by a 3 digit Load Index which is embossed into the tyre sidewall. This gives you the maximum load that can be carried at the speed indicated by the alphanumeric Speed Symbol. The Speed Symbol gives a range from A1 – G and relates to a forward speed in kph.
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