The powertap g3 shimano hub is ultra lightweight and the one of the most accurate power metre in the world since our introduction of the worlds first ever wireless power meter in 2006 weve been continually striving to improve it the powertap g3c and g3 hubs raise the bar to another level altogether lighter stiffer ant compatible and better than ever at 325 grams which is only 78 grams more then the a dura ace 9000 rear hub powertap have realised that data can be the difference between