The pro plt ergo drop handlebar a lightweight and strong 2014 aluminium road racing drop handlebar for oversized 318 mm clamp diameter pro plt ergo drop handlebar features lightweight and strong 2014 aluminium road racing drop handlebar for oversized 318 mm clamp diameter 2014 aluminium is a high strength aluminium alloy commonly used in the aircraft industry and a wide variety of high strength engineering applications making it the ideal choice to produce this l