So why can't we run the tire until we hit the steel band?
- Loss of impact cushioning (Reflex Modulus)
- With only 1-1/2" of rubber worn off tire, 100% of impacts are transmitted to machine (and operator) as there is not enough rubber to absorb (cushion) impacts
- Reduced Clearance
- The less rubber on the drive (front) tires, the lower the mast is to the ground and damage to the mast is expensive to repair while tires are inexpensive to replace
- Reduces Carrying Capacity
- As rubber is lost, carrying capacity is reduced and the tire will split or "radial crack" on the sidewall
- Reduced Heat Dissipation
- With less rubber to absorb and dissapate the heat the tire will start to break down. As the outside diameter is reduced, the faster to tire rotates again compounding the heat problem
How to measure a cushion tire
The manufacturers recommend replacing the tire when the outside diameter (OD) is 1-1/2" off the original OD. There are two methods of measuring a tire to determine whether or not it is worn out.
- Measuring it with a tape measure across the wheel
- Look for the manufacturers name molded into the sidewall of the tire. As a general rule of thumb, when the tire wears down to the name stamped on the tire, it should be changed.
Size | New ID (in.) | Replacement OD (in.) |
---|---|---|
14x4-1/8x8 | 14 | 12-1/2 |
16x5x10-1/2 | 16 | 14-1/4 |
16x6x10-1/2 | 16 | 14-1/4 |
18x6x12-/18 | 18 | 16-1/2 |
18x7x12-/18 | 18 | 16-1/2 |
18x8x12-/18 | 18 | 16-1/2 |
21x7x15 | 21 | 19-1/2 |
21x8x15 | 21 | 19-1/2 |
22x9x16 | 22 | 20-/12 |
28x12x22 | 28 | 26-1/2 |
Please note – this is a guideline only. |
What if you can read the tire size?
Sometimes when speaking to customers, they are unable to read the tire size on the side of the tire; The tire may be worn beyond the recommended minimal outside diameter (OD), or the tire may have been damaged and it is no longer readable.
Click here to see how you can determine your tire size.