Drive tyres and steering tyres
A wheeled combine is driven by its big front wheels, under the header, and steered by smaller rear wheels: the opposite of a tractor. The drive tyres carry most of the machine's weight, including a full grain tank, so their load rating matters more than on a tractor.
Common drive sizes are 23.1-26, 23.1-30 and 18.4-30. Steering wheels usually take 13.0/65-18, 12.0/75-18 or 10.50-18.
Fitting 18.4-30 instead of 23.1
Older New Holland Clayson combines (8055, 8060, 8070, 8080) list 18.4-30 as an alternative drive tyre. It is narrower than 23.1, so it sinks more in soft or wet fields, but it is made in Pakistan by General, Servis and Panther and is easier to find. Fit the same size and ply on both drive wheels, and make sure the rims suit the tyre.
Look after combine tyres
- Check pressures before the season and follow the operator's manual: a full grain tank adds tonnes to the drive wheels.
- Choose a high ply rating for drive tyres, which carry the grain tank and header.
- Look for cuts from stubble and stones, which wear the sidewalls.
- Between seasons, park on firm, dry ground out of the sun.






