A road transport system of a header of a harvesting machine includes two pairsof wheels andtwo wheel frames. Each wheel frame is connected to a pair of wheels. The twowheel framesare rotatable between a field operation position and a road transportposition. A header of aharvesting machine includes two pairs of wheels and two wheel frames. Eachwheel frame isconnected to a pair of wheels. The two wheel frames are rotatable between afield operationposition and a road transport position. A method of converting a header of aharvesting machinefrom a field operation mode to a road transport mode includes: releasing wheelframes of theheader from the header； rotating the wheel frames from a field operationposition to a roadtransport position； and enabling kingpin steering connections between at leastone of the wheelframes and a pair of wheels.
