Barbell squats without a squat rack / cage? | The Big 7 | Forum

I'm a member of two gyms with five locations, and none of them have a squat rack or squat cage.  I'm limited at the my main location (I'm usually there because it's where my sons have swim practice) to a 20-pound curl bar with 105 pounds of plates.  But the other locations have the standard 45-pound bars with plenty of weight.  Three of them have Smith machines, but I don't really like them.

What I've been doing is this:  I'll clean what I can and get it on my back, and my wife will run from side to side putting on plates (always 10's or 5's so I don't topple over).  I'll do my set, then she'll remove them until I get where I can handle the rest.  It works, but the loading / unloading just extents the agony…

I know I could always enlist a third person to help.  But I know there has to be a better way…  If I'm really wanting to do barbell squats rather than dumbbell squats, how can I best do this?