To get there they started out by keeping more than 60 percent of the bar width at the same 318 mm diameter as the clamp area then they strategically redesigned the carbon laminate structure adding strength around the clamp to handle clip on extensions and stiffness to handle sprinting loads despite its stout characteristics the slc2 cuts no corners in terms of ride quality due to zipp39s vibration absorbing vclc technology the only zipp carbon drop bar designed for clip on extensions