Technical Director for Compkart
- Fully mounted tire
- Wheel balancer (found at J3 Competition or other reputable kart retailers)
- Stick of wheel weights
- Side cutters (A.K.A. diagonal pliers), to cut wheel weights
- Wheel nuts, to fix wheel to balancer
- T-handle wrench, to fasten wheel nuts
Whether it's for a new or used set of tires, unbalanced wheels can cause vibration in your kart that can play a major role in chassis handling. This can cause inconsistent tire wear, corner handling, straight line speed, and in extreme cases, driver fatigue. It’s always important to balance all four wheels, but the fronts are going to be the most important if you’re in a time crunch. Also, a wheel should be balanced each time a tire is mounted to it.
To start, you’ll need a fully mounted tire with 15 pounds of pressure. This air pressure can vary, but 15 is a good standard that will allow you to see or hear any air leaks, while also not over inflating the tire. Mount the wheel to the balancer, just as you would to your kart.
Now we need to find the heavy spot in the wheel. To do so, lightly spin the wheel. When a heavy spot exists, the wheel will rotate back and forth on the balancer and eventually settle with the heavy spot at the bottom. If no heavy spot exists, the tire will come to a stop without wanting to rotate back. The majority of wheels will be off balance, but can range from ever-so-slightly all the way up to a significant amount.
After the wheel has settled, cut off your first piece of weight. This weight can vary, but start around a quarter of an ounce before you get more experience at predicting how much you’ll need. Now stick the weight to the opposite side of the wheel as the heavy spot, which will be the top of the wheel on the backside. It’s also very important to obtain good adhesion to the wheel so it does become a flying object when the wheel starts moving at full speed.
Now it’s time to see if the wheel is balanced or if you need more weight. Rotate the wheel 90 degrees counter clockwise (12 o’clock to 9 o’clock) and release. If the heavy spot still wants to rotate to the bottom, it’s showing that the heavy spot is still unbalanced and you’ll need to install a second weight.
If needed, stick another weight in the opposite direction as the heavy spot and repeat the process. The wheel is balanced when you can release the tire and very-little to no rotation is achieved.