Understanding Durometer Readings

Durometer is one of several measures of the hardness of a material. Higher numbers indicate harder materials; lower numbers indicate softer materials.

Hardness may be defined as a material’s resistance to indentation. The durometer scale was defined by Albert Ferdinand Shore, who developed a device to measure Shore hardness in the 1920s. The term durometer is often used to refer to the measurement as well as the instrument itself. Durometer is typically used as a measure of hardness in polymers, elastomers, and rubbers.

Shore’s device was not the first hardness tester nor the first to be called a durometer (ISV duro- and -meter; attested since the 19th century), but today that name usually refers to Shore hardness (other devices are simply called hardness testers).

sooooo, let’s boil down what these means to you, a tire consumer and why durometer readings are incredibly important to engineering tires specific to unique terrains, vehicles, load ratings and air pressue (psi).  To make things easy, a reading of 1 is extremely soft, 100 would be extremely hard.

The term “Durometer” means both the measuring tool, and the unit of measurement. You use a durometer to check the tires durometer.  Generally speaking, a low durometer tire will stick better, and give better traction. But it wears out faster. As a tire heat cycles and wears out, the durometer rises.

The durometer is extremely heat dependent.  As tire compound (rubber) raises in temperature, it becomes sticky. This is important to consider because checking the durometer readings of your cold tires in your garage more than likely  will not alter the readings.  Checking your tire durometer readings directly after use or in direct sunlight in temperatures over 70 degrees may affect your readings.  Trust-worthy tire manufacturers will openly supply durometer readings however all technical specs are based on cold compounds in temperature controlled environments.


EFX TIRES – DUROMETER SPECS

STYLE PART NUMBER SIZE Durometer range
BLADE FA-807 22X11-10 4PR  68±3
BLADE FA-806 23X10.50-12 4PR  68±3
BLADE FA-817 23X10R14 4PR  68±3
FUSION S/T FA-827 205/30-12 4PR  68±3
FUSION S/T FA-826 205/30-14 4PR  68±3
FUSION S/T FA-825 23X9.50R12 6PR  65±3
HAMMER FA-828 22X9.50-10 4PR  68±3
HAMMER FA-829 23X9.50-12 4PR  68±3
HAMMER FA-830 23X9.50-14 4PR  68±3
HAMMER FA-831 22*9.50-12 4PR  68±3
LO-PRO FA-812 225/35-12 4PR  68±3
MOTO350 W-25-8-12 25X8-12 6PR  65±3
MOTO350 W-25-10-12 25X10-12 6PR  65±3
MOTOBOSS MB-28-10-14 28*10.00-14 6PR  65±3
MOTOBOSS MB-30-10-14 30*10.00-14 6PR  65±3
MOTOBOSS MB-32-10-15 32*10.00-15 6PR  65±3
MOTOBOSS MB-34-10-16 34*10.00-16 6PR  65±3
MOTOCLAW MC-26-9-12 26X9.00-12 6PR  65±3
MOTOCLAW MC-26-11-12 26X11.00-12 6PR  65±3
MOTOCLAW MC-29-10-16 29X10.00-16 6PR  65±3
MOTOCLAW MC-27-10R-14 27*10R14 8PR  65±3
MOTOCLAW MC-30-10R-14 30*10R14 8PR  65±3
MOTOCLAW MC-28-9R-15 28X9R15 8PR  65±3
MOTOCLAW MC-28-11R-15 28X11R15 8PR  65±3
MOTOCLAW MC-32-10-16 32X10R16 8PR  65±3
MOTOCLAW MC-33-10-18 33X10R18 8PR  65±3
MOTOCLAW MC-32-10-14 32X10R14 8PR  65±3
MOTOCLAW MC-31-10-15 31X10R15 8PR  65±3
MOTOCLAW MC-28-10-14 28X10R14 8PR  65±3
MOTOFORCE MF-25-8-12 25*8-12 6PR  65±3
MOTOFORCE MF-25-10-12 25*10-12 6PR  65±3
MOTOFORCE MF-26-8-14 26*8-14 6PR  65±3
MOTOFORCE MF-26-10-14 26*10-14 6PR  65±3
MOTOFORCE MF-24-8-12 24*8-12 6PR  68±3
MOTOFORCE MF-24-10-12 24*10-12 6PR  68±3
MOTOGRIP MG-26-9R-14 26X9.00R14 8PR  65±3
MOTOGRIP MG-26-11R-14 26X11.00R14 8PR  65±3
MOTOGRIP MG-26-9R-15 26X9.00R15 8PR  65±3
MOTOGRIP MG-26-11R-15 26X11.00R15 8PR  65±3
MOTOGRIP MG-28-9R-14 28*9R14 8PR  65±3
MOTOGRIP MG-28-11R-14 28x11R14 8PR  65±3
MOTOHAMMER MH-27-9R-14 27X9R14 8PR  65±3
MOTOHAMMER MH-27-11R-14 27X11R14 8PR  65±3
MOTOHAMMER MH-28-10R-14 28*10R14 8PR  68±3
MOTOHAMMER MH-31-10R-14 31X10R14 8PR  65±3
MOTOHAMMER MH-30-10R-15 30X10R15 8PR  65±3
MOTOHAMMER MH-30-10-14 30X10R14 8PR  65±3
MOTOHAMMER MH-32-10-15 32X10R15 8PR  65±3
MOTOHAMMER MH-32-10-16 32X10R16 8PR  65±3
MOTOMAX MM-27-10-14 27X10-14 6PR  65±3
MOTOMAX MM-27-12-14 27X12-14 6PR  65±3
MOTOMONSTER M-30-10-14 30X10-14 6PR  65±3
MOTOMTC W-26-9-12 26X9-12 6PR  65±3
MOTOMTC W-26-11-12 26X11-12 6PR  65±3
MOTOMTC W-26-9-14 26x9-14 6PR  65±3
MOTOMTC W-26-11-14 26x11-14 6PR  65±3
MOTOMTC W-28-10-14 28X10-14 6PR  65±3
MOTOMTC W-28-10-15 28X10-15 6PR  65±3
MOTOMTC W-30-10-14 30X10-14 6PR  65±3
MOTOMTC W-30-10-16 30x10-16 6PR  65±3
MOTOMTC W-32-10-18 32X10-18 6PR  65±3
MOTOMTC W-27-10-14 27x10-14 8PR  65±3
MOTOVATOR MV-30-95-16 30×9.5R16 8PR  70±3
MOTOVATOR MV-30-95-15 30×9.5R15 8PR  70±3
MOTOVATOR MV-30-95-14 30×9.5R14 8PR  70±3
MOTOVATOR MV-28-95-14 28×9.5R14 8PR  70±3
PRO-RIDER FA-811 205/50-10 4PR  68±3
PRO-RIDER FA-814 215/50-12 4PR  68±3
PRO-RIDER FA-821 215/65R10 4PR  68±3
PRO-RIDER FA-824 18x8.50-8 4PR  65±3
SANDSLINGER SS-27-10-14 27X10.00-14 4PR 73±3
SANDSLINGER SS-27-13-14 27X13.00-14 4PR  73±3
SANDSLINGER SS-29-14-14 29X14-14 4PR  73±3
SANDSLINGER SS-29-11-14 29X11-14 4PR  73±3

For more information on durometer readings click here (Wiki)