The holes that are built into the sidewall of Sentry tires are known as Deflector Holes (or Aperture Holes). They are vital to maximizing each tire’s quality and operating life.

Raw rubber needs to “cured” to the right time and temperature to achieve the most optimal elasticity. Too much heat and the rubber will harden and become brittle, which will make the rubber “flake” off during operations. Too little heat during the manufacturing process will make the tire too soft. Consequently, the tire will start peeling between the different layers because optimal bonding has not been achieved.

During the curing process, the biggest challenge is to ensure the heat is properly distributed into the center of the tire. For example, suppose you bake a cake at a really high temperature in a short amount of time. In that case, the cake’s exterior will be crusty and possibly burnt. The cake center may still be very “liquidy” since the heat has not gotten a chance to distribute to the cake’s core. If you bake a cake at too low of a temperature, it will probably take triple the amount of time to cook.

Therefore, the Deflector Holes allow us to inject heat directly to the tire’s center and ensure that the rubber in the center is appropriately “cured” without over curing the tire’s exterior.

During regular tire operation, heat starts building up on the tire’s surface. The longer you run the tires, the more the temperature gets distributed into the center of the tire. This usually wouldn’t be an issue with air tires since as heat builds up, the air simply expands in the tire. Air tires are built with a certain degree of elasticity, allowing the tire to expand without damaging the rubber. Too much air and it will pop like a balloon.

However, with solid tires, the heat has nowhere to expand; thus, it gets absorbed into the rubber. As more and more heat builds up, it changes the rubber’s properties, making it harder and harder. The Deflector Holes help the heat escape from the center of the tire more quickly while the machine is resting.

Since solid tires have no air in them, the ride can be quite rough, increasing operator fatigue and discomfort. In more severe cases, operator injuries can occur. The Deflector Holes serve as a cushioning mechanism to absorb shock from debris impact. When combined with the “flat-proof” nature of solid tires, Deflector Holes dramatically enhance your operators’ productivity.