In Southeast Asia most tire manufacturers have factories producing our motorcycle rubbers. Tires are the silent heroes of modern motorcycling and tire development is occurring at a great rate. Most of us motorcyclists depend daily on the strength and durability of our tires, even without knowing anything about the production process or development. So how are tires our tires made?
Rubber is harvested from rubber trees and is then mixed with other compounds in a big pot to make the tread mixture. This gunk is then extruded from a machine in a long strip and cut into individual tire lengths.
The tire carcass is then made by weaving steel or textile together and sandwiching it between rubber sheets to make a flexible structure. Thread angles are varied to give the carcass different strength properties. Steel cables are then formed into circles to create the tire's bead, then this is attached to the carcass to make the tire's final body before the tread is added. This is called a green tire, although it isn't green.
The green tire is put into a mold and heated while a bladder inflates inside the tire to force it into the mold. The inside of the mold contains the tire's tread pattern. Then it's cooked to vulcanize the compounds and bond it together, creating a tire.
The little bits of rubber that stick up from new tires are called spews and are where excess rubber escaped from the mold up breather gaps. These spews are trimmed off and the tire is complete.