The Barbell’s Anatomy
General Information
Modern barbells, or Olympic-type barbells, to be more specific, usually consist of two discrete segments, the shaft and the sleeve. Between them, there is a link; this is typically either a bushing or a bearing. The latter two are the main differentiating factors determining a bar's use. Additionally, depending on the barbell type, the knurling and its elasticity, also known as whippiness, are significant differentiating factors. Lastly, a crucial factor determining a quality barbell is its tensile strength.
The Shaft: Athlete’s Grip
Knurling
The knurling is the grip section on a barbell's shaft, marked with cross-hatched cuts. Depending on the barbell type, this area might be gentler, widely known as standard or aggressive knurling. Typically, barbells used in Powerlifting require more aggressive knurling to secure their grip position in hefty loads. On the other hand, Weightlifting and Strength Training barbells are more prone to standard knurling, ensuring movement flexibility.
Center Knurl
The center knurl is also a cross-hatched marked area in the middle of a barbell's shaft. Depending on the barbell's type and usage, the center knurl may be present or absent. The presence of the center knurl is often desired in Powerlifting barbells, as it secures the bar's position in exercises like squatting.
The Sleeve: Rotational Parts
Bushing
A bushing is a metal ring usually made from bronze. Its surface is highly smooth, and its thickness makes it a highly durable material, more than suitable for the rotational mechanism of the barbell. Due to its decent ratio of medium rotational speed and heavy durability, barbells using bushings can sustain demanding workouts where overloading and dropping are necessary.
Bearing
A bearing is a metal ring made from steel. The supremacy of this material lies in its internal mechanism. Needle bearings contain multiple tiny rods on their inner surface, and each one of them spins independently. This mechanism allows for a smoother, faster spin with a long duration, ideal for Olympic Weightlifting training.
Sleeve Length: Maximum Loads
Tensile Strength
Tensile strength defines the maximum amount of stress a barbell can withstand while pulling without reaching a breaking point. Its measurement pressure unit is pounds per square inch or mostly known and abbreviated as PSI. Barbells typically exhibit a range of 150,000-230,000 pounds per square inch. However, the higher a bar's tensile strength is, the more durable it is. Barbells with more than 200,000 PSI are usually worth investing in as they can last longer, sustaining more training sessions and, thus, heavier workouts.
Loadable Sleeve Length
Loadable sleeve length is the measurable distance between the bar's edge and the sleeve's flange. Along with the width of the loadable plates, sleeve length is the ultimate denominator of the maximum load a barbell can handle. Powerlifting bars usually have more extensive sleeve lengths and are typically loaded with narrower steel plates.
Flange Width: The Road to Whip
Flange Width
The flange is the innermost part of a barbell's sleeve. Its width varies depending on the bar's type and usage. Typically, the thicker the flange is, the easier the rack work gets, as it prohibits the bar from colliding on the rack's uprights. A thinner flange is commonly desirable in Powerlifting barbells due to more loadable sleeve space requirements and minor barbell bending.
Whippiness
Whippiness is the amalgamation of how much pressure can withstand and how easily a barbell will flex under a heavy load without permanently deforming its shape from bending. The more whippiness a bar has, the more the barbell load will shift with momentum. Whippiness is a highly demanded attribute in Olympic weightlifting, as it allows a skilled lifter to bounce the weight upwards.
