What is a cross ply tyre?
The cross ply tyre was invented in the 1920s and marked the end of the beaded edge tyre which was used until then. The advantages of this tyre were a lower accident risk and easier mounting of the tyres. Polystyrene plies were used for the first time – hence the name. These were worked into the tyre diagonally. At first the tyres were mounted using a tube. Not until the end of the 50s was it possible to mount the tyres without a tube by using an inliner in the tyre in connection with a hump rim. The measurement was still in inches, for example 5.60-15 or 5.50-18.
