Barbell collars are used on barbells and dumbbells to prevent the weight disk from loosening or falling off. These locking devices are placed on the bar after the weight disks are added. The barbell collar is then locked onto the bar by turning a locking bolt or by a spring mechanism.
Weight lifting is a very exact science. The movement of the weight disks can greatly influence the lifter’s ability to balance and lift the weight. Barbell collars help to keep the weight steady by locking it in place on the bar. This aids the lifter’s ability to balance the weight and also keeps the weight centered over the lifter’s body.
Another benefit of barbell collars is the reduction of injury to the lifter. Loose weights can allow the weight to shift and pull the lifter off balance. When this happens, the lifter is forced to strain unevenly against the shifting weight and the result is often serious injury. Barbell collars keep the weight from shifting.
Newer models of barbell collars are coiled spring devices that lock onto the bar and are more easily released than the bolt-on models. This results in time savings for the lifter. Ease of operation and the ability to remain tight without loosening are responsible for the popularity of these new barbell collars in many gyms.
Many of the older type of collars were held in place with a bolt. Once the weight disks were placed on the bar, the collar slid up against the weight disk and the bolt was tightened against the bar, locking it in place. Often this bolt would slip against the bar and allow the weight to shift. This slipping would not only allow the weight to shift, but would also damage the bar.
Early attempts to combat slipping barbell collars were threaded bars. These threaded bars had collars that were threaded on after the weight disks were placed on the bar. While the threaded collars were somewhat successful in holding the weights tight, they were often difficult to remove and often required tools to loosen them once tight.
The modern weight machine was designed to help combat the negative affects of loose barbell collars. The intention was to keep the weights from shifting due to loose weight. While effective in that regard, many professional weight lifters prefer the traditional free weights and the invention of the spring clip-type collar was born. This type of collar is used in amateur weight lifting and even Olympic events.