Ballasting your Agricultural Tyres

By Phil Rowntree - Farm Tender - 0428 659 056

How often do you change ballasting and or tyre pressures on your Tractor? IF, VF, LSW, rag, radial, 4, 6, 8, and 10 ply tyres. Width, profile and size: what do I need, and what's the difference? So many questions when it comes to wheel Equipment.

Let's apply the following few paragraphs to a tractor that is towing an Air Seeder. SAY A JD 9570R ON DUAL 80/70R38'S.  Let's also note that different tyre and machinery manufacturers will recommend different setups. Also, ballasting calculators are available online to point you in the right direction.

It's a Goldilocks challenge to get ballasting perfect; however, getting close to the mark can dramatically improve the performance and efficiency of your Tractor. 

An over-ballasted tractor can have considerably higher fuel consumption (low amount of wheel slip), and at the other end of the scale, a ballasted Tractor (too much wheel slip) will have the same high fuel consumption. Clear as mud?

When setting a new machine up in the paddock, I would like to see a 55% rear and 45% front weight ratio while stationary and no drawbar load applied. Once under load, the aim is 60% rear and 40% front, and throughout the day, this can change just because of fuel tank positioning. From there, visually, we would set tyre pressure to give 3 lugs on the ground front with 2 - 2.5 lugs on the ground rear. When under load preference front and rear is 2.5 - 3 lugs on the ground. 

At this loaded point we need then to assess wheel slip and again this will vary in opinion. My goal was from 5% to 10%. If there is excessive slip more weight and increase tyre pressure to suit 2.5 - 3 lugs on the ground. If slip is low, less weight tyre pressure down to suit 2.5 - 3 lugs on ground.

Having your Tractor ballasted and pulling at a suitable slip can save a considerable amount of wear, time and fuel. Too much weight means you are using extra fuel just to move the weight, and too much slip gives this same result. Factor 3% less slip to your fuel usage, and you may get a shock. 

The "just right" ballast level for your Tractor depends on your individual operation. Some Farmers are okay with a little more slip and a lighter machine, while others want to pin all the power to the ground.  Please always refer to the tyre manufacturer's recommendations.

Ultimately this is a short version of what really needs to be managed on a case by case basis. I suggest consulting your Machinery and tyre Dealer.