The 18″ diameter press wheel is parallelogram controlled not the tyne, and the press wheel pressure can be altered on the run as soil types and moisture conditions vary.
55mm (2″) semi pneumatic press wheels are standard for most machines, and some customers use solid tyres behind their tractor wheels to prevent the tyres from choping out so badly.
In sandy soils the 80 mm wedge prevents side walls from caving in but still allows the speartip to penetrate.
100mm (4″) soft flat tyres work well for customers with very soft country, because it prevents the tip from penetrating too far.
NEW! Ask us about the Agi-Hub Zero maintenance wheel which has the seal and bearing fully contained within the casing. This prevents the seal from getting chopped out by trash and dirt from turning the grease into a grinding paste.