Vittoria randonneur tech g road bike tyrevittorias randonneur tech g road bike tyre represents a real revolution in bicycle tyre design with the use of a unique g graphene material produced by vittorias technology partner directa plus g isotech compound results in a durable tyre that is ideal for city commuting touring use and even wet weather riding advanced compoundstandard rubber tyres have a requirement to be optimised for one or two characteristics such as making the tyre harde