Threads Per Inch Explained
The tire casing is the underlying structure of the tire, providing a stability and a frame for the rubber compound of the tire tread to adhere during construction. The casing is constructed of a woven fabric like material laid across one another at a 45º angle to the direction of rotation allowing the tire to bend and flex in a predictable and controllable manner. The density of the weave of the casing is defined as Threads Per Inch (TPI), and in general the higher the TPI number, the higher quality of the resultant tire. Higher TPI numbers represent finer threads making up the casing weave, creating a more supple tire better able to conform to the ground, providing a better handling and performing tire.
Ere Research road tires use top performing 120 TPI or more economical 60 TPI casings for the ultimate in supple and responsive tires.