Continental grand sport extra road bike tyrethe continental grand sport extra road bike tyre is a high performance tyre designed for heavy duty use a supple 180 tpi casing provides great rolling handling and grip with new nytech breaker technology to offer additional puncture resistance and all at a great price the grand sport extra features a double nytech breaker and a 3ply sidewall making it a real option for long hard training miles or epic spring autumn sportive rides featuressize