A rubber compound for the preparation of portions of pneumatic tyres comprising a cross-linking unsaturated chain polymer base, a filler system and a vulcanization system. The filler system comprises (a) a first carbon black having a surface area less than or equal to 170 m2/gr in a quantity greater than or equal to 25 phr; (b) a second carbon black having a surface area greater than or equal to 250 m2/gr in a quantity such that the ratio between the quantity of the first carbon black and the quantity of the second carbon black is greater than or equal to 3 and less than or equal to 10; (c) a carbon black dispersing agent in a quantity of less than or equal to 1 phr.