Olympic bar

An Olympic bar has thick sleeves that spin independently of the shaft, usually on bearings or bushings, which lets the plates keep rotating instead of twisting the bar in your hands during lifts like cleans or snatches. The 2 inch sleeve diameter is the reason Olympic plates, which have a matching 2 inch hole, only fit this style of bar.

For apartment training, length is the main constraint to check, since a full 7 foot competition bar needs more room to load, rack, and maneuver than a small room may have. Several shorter bars in the 5 to 6 foot range exist specifically for tighter spaces, trading some load capacity and whip for a smaller footprint.

When buying, compare weight capacity and whip to how heavy you actually plan to load it, since a bar rated far above your needs may feel stiff for lighter, faster lifts. Check the knurl pattern for center marks if you plan to squat or bench with consistent hand spacing. A common mistake is buying an Olympic bar after already owning standard plates, since the hole sizes do not match and neither will fit the other.