The zipp service course sl 70 ergo handlebar is an aluminium handlebar which is a bike fitters go to bar for its all round excellence the ergo bars with their flat tops and 70mm reach the horizontal distance from the bars stem clamp area to center of the brake perch and its 128mm drop vertical distance from bars stem clamp area to bottom of drops it helps put the rider low and in control without compromising comfort please note zipp handlebar widths are measured from the centre to centre