Barbell is the lifeline of gym lovers. Gym goers (this excludes calisthenics guy), no matter bodybuilders, powerlifters, or weightlifters, all need to frequently perform barbell exercises. The barbells for these different categories also have some variations, be them big or small. This article will provide an introduction on the variations among the barbells. I group the barbells into three main categories: regular, powerlifting, and weightlifting. These categories do not include the special kinds of bars such as trap bars and curl bars.
From top to bottom, men's, women's, special use weightlifting bars
The most significant variation is the weightlifting bar. To analyze the design of weightlifting bar, one needs to start from its functions: snatch and clean jerk. Both movements require extremely strong grips on the bar, as well as extremely fast speed of lock-out movement. The strong grip can be provided by heavy knurling on the grip area, and since snatch and clean have different grip widths, the whole bar should be knurled. However another concern is that when the athlete starts to pull the bar, the knurling touches and scratches his/her shin; when the bar is locked on the athlete's collarbone, the knurling also causes unnecessary pain. To reduce the friction on such body contacts, those portions are made smooth. There is one short knurling portion in the middle of the bar, but that is left for historic reasons (one-handed snatch). I personally think it is quite helpful for grabbing the bar. Besides knurling, in order to get a strong grip one also has to use the hook grip. This makes the weightlifting bar thinner than the regular bar, which makes it easier to wrap fingers over on the thumb. There are also notches on both the inner and outer portion of the bar, which are references for the athlete to grab on. The last design involves the dynamic structures of the bar: the sleeves and bearings. Those roller bearings allow the weight plates to rotate freely during the lock-out motion, reduces the risk for wrist or elbow injury and the loss of grip during the process. This design makes such a big difference. I have tried doing cleans with a regular bar, and constantly I felt the loss of grip since the angular momentum on the plates brings the entire bar into rotation and forces itself to leave my palm. This is a significant phenomenon even in standing row with the bar. On the other hand, I have tried bench press with weightlifting bar, and I can feel how shaky my wrists were since they are able to rotate freely under pressure of the weights, making the whole process very unstable. The weightlifting bar is also highly malleable, allowing a few inches bend to provide the room for a lift from the ground, as well as the "bounce-up" for squat clean, which saves the athlete some energy. A standard weightlifting bar is 20 kilograms in weight, 28mm in diameter, and 220cm in length for men, and 15 kilograms in weight, 25mm in diameter, and 201cm in length for women (Olympic games use kg as the unit). Crossfitters should use this type of bar.
From top to bottom, barbells for weightlifting, common practice, and powerlifting. Some common lengths of regular barbells: 120cm, 150cm, 180cm. Diameters: 26mm, 28mm, 29mm
The regular bar, with the necessary knurling parts to provide grip, may remove the knurling in the middle to reduce production costs. As mentioned above, the bearings are tighter to prevent the instability from rotation.
The regular bar is the most common type of barbell in the gym and can be seen in all kinds of exercises other than weightlifting, including bench press, some casual squats and deadlifts, or even curling and rowing. Due to its popularity, there are types with different malleability, weight, and length. Some make 35-lb bars for women and 45-lb bars for men, some make shorter and lighter bars for beginners. Some only leave the smooth portion in the middle, for a better touch on chest or back. Tons of variations.
The powerlifting bars mainly focus on the "three big ones": bench press, deadlift, and squat. Those are not the "casual" types of the regular bar since huge weights will be applied to them during competition. Barbells for each item are designed slightly different to fit for the specialty of that motion. Bench press emphasizes stability, and the forces are pressing into your palms instead of leaving them, so a thicker diameter can help with the grip. Deadlift shares some characteristics with the clean, so deadlift bar is quite similar to weightlifting bar, thinner and more malleable, but does not have rolling bearings. Squat bar maintains the middle knurling portion to increase friction on athlete's back and can stand extremely high pressure, usually over 3,000 pounds, without noticeable deformation after removing the weights.