A question that Goodyear is frequently asked is ‘what is the biggest tyre you make?’ The answer is the RM-4A+ Off The Road tyre in size 59/80R63, which is as tall as a large elephant and of a similar weight . This massive OTR tyre has been developed to carry hundreds of tons of rock and other materials and is part of the RM (Rock Mining) range of tyres the company produces.
This gigantic 63 inch (rim diameter) tyre is sold around the globe to be fitted to the world’s largest mining and earthmoving equipment operating typically in coal, hard rock, gold and copper mines. At 4.023 meters in overall diameter, this tyre is taller than the legal height of most semi-trailers in Europe (4 metres) and a metre taller than a basketball hoop. Its 5,400 kilograms are packed with advanced technologies and it is capable of carrying a load of 100,000 kgs at speeds of up to 50 km/h.
The technologies the tyre contains are related to its materials, construction and design. The 63-inch tyre has a steel casing and belting construction, and is precision-made, using state-of-the-art, fully integrated tyre manufacturing equipment. Computer simulation tools were used to assist in the tyre’s design, and Goodyear works closely with Original Equipment Manufacturers to help ensure tyre size compliance on their vehicles. Goodyear’s 63-inch tyre has been designed for optimal performance. Its features include Goodyear’s cool-running CycleMax tread rubber compound; interlocking centreline grooves for enhanced stability and additional heat relief. High-angle/non-directional grooves help promote traction and a sidewall scallop helps reduce heat build-up. The 63-inch tyre is available in two sizes: 53/80R63 and 59/80R63; with three compound variations and two tread depths (E3 and E4), which result in a total of 12 variants being available.