The name “drag” curl comes from the movement of the bar – you actually “drag” the bar up the torso. With the front shoulders out of the equation, the majority of the work is done by the biceps.
The drag curl is a variation of the standard barbell curl that attempts to eliminate the front deltoid involvement from the movement. The answer is yes, drag curls are a modification of the standard curl that can maximize your efforts and really work the biceps harder The question is: can the curl be modified to hit the biceps better ?
The barbell curl is the most popular biceps exercise, and with a good reason – it works the biceps nicely and builds mass.