Tech Tips - Tires
-as seen in The Pulse Newsletter, October 2017
Where the Track Meets the Tires
Before each pull starts, all tractors must enter their respective classes and ensure they are set up properly for each class. Among specified requirements for each tractor class, proper hitch height and the weight of your tractor must meet exact criteria.
But there’s something a lot of pullers might not think about checking. The track! Is it soft? Is it hard? It is tightly packed? Is it loose? Is it wet? Or is it dry? All of these different track conditions dictate different tire pressures.
And what about your tires? Are they wide? Narrow? Stock? Professional? And more importantly - what about tire pressure?
Let’s talk about tire pressure and how it affects your pulling performance.
Tire pressure is very important in pulling...and there are many factors that play a role in deciding the correct pressure for your tires during a pull:
Different tire pressures create different degrees of traction during a pull.
Different tire types from different companies also require different tire pressures.
Different rim width is something to consider when checking tire pressure. The wider the rim, the more air your tire needs in order to keep the middle of the tire in contact with the ground.
The condition of the track is very important when preparing for a pull - a loose track requires less tire pressure. Harder tracks usually requires more tire pressure to create the perfect amount of traction.
All pullers should make notes at each pull, recording the track conditions; the tire pressure you use; the type tires you use; and how well you pull. These notes will help you when you return to that track to pull again.
When measuring tire pressure, you should have a tire gauge that tops out at only a few pounds...maybe 25 pounds to the maximum. That way you can be very precise in your tire pressure measurements. After all, sometimes you may only want to inflate or deflate your tire a small amount, possibly as little as 1/2 pound, more or less.
And keep in mind, most pulling tires leak over time, so you need to check tire pressure immediately before pulling your tractor. Just because the tire pressure was correct last week, doesn’t mean it didn’t change over time. The weather and temperature might effect tire pressure as well.
Another clue to your correct tire pressure setting is left behind on the pulling track itself. After your pull, when you unhook from the sled...pay attention to the tracks and holes your tires make in the track. Important clues lie there in the dirt. If you made holes in the track with your tires, check their shape.
A correct tire pressure digs a flat hole in the track. However, if your tire digs a hole with a mound of dirt in the middle, your tires are sucking the ground up in the middle of the tire...therefore, your tire pressure is too low. Over-inflated tires will leave a skinny hole in the track.
If you have questions about how your tractor hooks to the sled, ask the sled-operator or any track official.