OTR Tyres for Heavy Equipment: Sizes, Tread Types and How to Make Them Last

Off-the-road (OTR) tyres carry loaders, articulated and rigid haul trucks, graders, telehandlers and wheeled excavators. On large mining trucks a single tyre can cost tens of thousands of dollars, and tyres are often the second-largest operating cost after fuel.

Reading an OTR tyre size

• 23.5R25: 23.5 inches section width, radial construction (R), 25-inch rim. A common size for medium wheel loaders.
• 29.5R25, 26.5R25: larger loader and ADT sizes.
• 59/80R63: the giant ultra-class haul truck size (59-inch width, 80% aspect ratio, 63-inch rim).

Radial vs bias

Radial tyres run cooler, give better traction and longer life on haul roads and loaders. Bias-ply tyres have stiffer sidewalls and resist cuts, still used in some severe-service and low-speed applications.

Tread types (TRA codes)

Deeper treads resist cuts and last longer in abrasive rock but run hotter at speed.

How to extend tyre life

• Correct inflation: under-inflation is the most common cause of premature failure. Check pressures cold.
• Haul road maintenance: remove spilled rock and keep a grader working.
• Avoid wheel spin on loaders; use traction control and appropriate rimpull settings.
• Watch TKPH/TMPH ratings on haul trucks so tyres do not overheat.
• Rotate and repair cuts early.
• Consider tyre chains for loaders in severe rock.

Solid and foam-filled tyres

In scrap and demolition, solid or foam-filled tyres eliminate punctures but give a harsher ride and add weight.