CHIKO Bottom Rubber Wearability Test

Grind the bottom rubber with two pieces of 40# sand paper,

back and forward for more than 25 times.

The weight laid on top of the sand paper shall be 1400g for 75 mm² rubber, 1700g for 76-95 mm² rubber and 2200g for 96-120 mm² rubber.

Qualification Standard:

Heel of Grade A:  Loss of rubber thickness after test < 0.4mm

Heel of Grade B:  Loss of rubber thickness after test < 0.6mm

Heel of Grade C:  Loss of rubber thickness after test < 1.0mm