The tractor and machinery industry is welcoming a challenge by the Minister of Agriculture to train New Zealanders rather than continue relying on seasonal migrant workers.
Suppliers claim that fitting duals offer several advantages. Not least is the ability to create more grip from the greater surface contact between the tyres and the ground, that in turn means less wheel slip, less wear and tear on tyres and less fuel consumed.
Add to that good agronomic reasons such as reduced soil compaction leading to better soil structure, allowing the free passage of water and nutrients to plant roots: these should offer increased production, making the case for fitment of duals a convincing one.
Euroduals, distributed in NZ by Ag- Attachments, Hamilton, are manufactured by Schaad Starco in Switzerland. This company is said to be Europe’s largest supplier of wheels, tyres and complete wheel/tyre assemblies to the aftermarket and OEM markets.
The company claims that its attention to detail during manufacture sees the fitment of calibrated spacer rings that offer a perfect fit. This removes the risk of “jamming during fitment and removal and ensures the loads imparted by the fitment of the secondary wheels are directed through the spacer ring and not the clamps. This results in the number of clamps required to secure duals being reduced”.
MD Plus and HD Plus fitting systems are offered for tractors rated to maximum horsepower settings of 200 and 600 respectively. Both have a heavy-duty ‘socket’ that is fitted to the original inner wheel, that connects the clamp with the outer secondary wheel via a short threaded and adjustable rod.
The design means that tensioning or releasing clamps is quick and easy, with the connecting rods removed from the sockets without the need for hooking or unhooking.
The other key design difference sees the clamping ring being placed inside the dual wheel assembly, meaning a short distance for the connecting rods, resulting in secure attachment, even when reversing, with the added benefit that tractors up to 200hp will only need four clamps, even when fitted with 42-inch wheel equipment.
Likewise, that same design detail means there are no alignment issues requiring heavy and cumbersome wheels to be ‘spun’ to align properly with the clamps. Once the wheel is positioned against the original inner wheel, clamps can be quickly attached and tightened, meaning that when not required the duals can be removed to prevent excessive wear or reduce transport width.
“The quality of the manufacture of these dual sets means that fitment is extremely precise, letting us reduce the number of clamps down to four on most tractors,” says national sales manager for Ag Attachments, Martin Gray.
“In some situations, especially if the horsepower creeps above 400hp, we would suggest that six clamps might be required.”