The Effect of Tire Break-In on Force and Moment Properties

A tire break-in procedure has historically been used prior to tire force and moment testing for three reasons: to reduce variability, stabilize the data, and simulate service. For low slip angle force and moment data it is shown that the tire break-in does not achieve these objectives.

Break-in is a result of viscoelastic changes and permanent deformation in the tire carcass materials, not a surface roughening or wear effect as has previously been assumed.

It is recommended that no break-in be used in low slip angle force and moment testing. This action would eliminate the break-in variable and lead to reduced testing variability and more stable data.