What does durometer refer to in a mountain bike tire?

The durometer is a measurement of the hardness of a mountain bike tire's rubber compound. It is measured on a scale from 0 to 100, with 0 being the softest and 100 being the hardest.

The durometer of a mountain bike tire affects its traction and rolling resistance. A softer tire will have more traction but will also roll slower. A harder tire will have less traction but will roll faster.

The ideal durometer for a mountain bike tire will depend on the type of riding you do. If you are doing a lot of climbing and descending, you may want a softer tire for increased traction. If you are doing a lot of long-distance riding, you may want a harder tire for reduced rolling resistance.