I've just upgraded from a 1" bar to my first 2" olympic bar. I'd never realised until it arrived that the collars rotate on the bar.
Why is this and why is it not seen on 1" bars?
1 Answer
Olympic barbells are designed to perform Olympic and Olympic-adjacent lifts which are the Snatch and Clean & Jerk.
As you can see they are very active movements, and the plates don't spin as the lifter rotates their hands around the bar.
If the collars didn't rotate, the added friction on the weight to the collars would rotate the entire bar including the part that the lifter is holding on to. This would greatly increase the difficulty of the lift as well as just make it a lot more unsafe.
With rotating collars, the weight moves freely during the motion and the lifter doesn't have to worry about stabilizing.
The 1" bar simply is not designed to perform such movements (at least not well). It was designed for affordability and ease of maintenance since there aren't any ball-bearings that need oiling up every once in a while.
