Vittoria ultralite road bike tubevittoria ultralite road tubes in various sizes and varying presta valve lengths features sizes 650 x 1923c 700 x 1923c or 700 x 2528c presta valve 36mm 42mm or 51mm 51mm presta valve has a replacable valve core weights 55g to 95g each depending on size buyvittoria wheels tyresfrom chain reaction cycles the worlds largest online bike store