Xpeed D-Series Olympic Curl BarXpeed D Series Olympic Curl Bar The Xpeed D Series EZ Curl Bar is a shorter 120cm length barbell. Traditionally this style of bar is used for exercises that work smaller muscle groups such as your biceps and triceps. In addition, it can often be used in place of a standard barbell when needed for exercises such as bent over rows. A curl bar allows you to use an underhand grip with your wrists slightly supinated, or turned out. Alternately, you can