The discreet coloured bead strip allows you to colour coordinate the tyre to match your bike perfectly without losing the blackchili tread performance the gp4000 s ii is versatile enough for race wheels or training wheels read the wiggle blog review of the continental grand prix 4000s ii folding road tyre here continental have also expanded the size range with an additional 28 mm version added this provides improved grip in poor riding conditions increased puncture protection and greater com