Technical Bulletins

SIDEWALL UNDULATION - RADIAL TIRES

F-026-X

Date:

SEPTEMBER, 1991



The sidewalls of radial rear tractor tires may exhibit a wavy (undulated) appearance, to some degree. The undulation appears as a raised area below each lug, in both sidewalls.

All radial rear tractor tires may exhibit this phenomenon, because the body cord path of all plies run in the same direction (bias ply tires have the cord paths crossing one another) allowing the sidewall more freedom to expand. 

This expansion may vary slightly in the upper sidewall area based on tread pattern lug locations, resulting in slight undulations (see photo).

The undulations are an appearance condition only. They do not affect tire performance. Customers should be made aware that undulations in the sidewalls of radial rear tractor tires are normal.