I started lifting weights (again) and accurately tracking my progress (I bought a “cheap” workout and weight loss plan, which requires a lot of data so you can see your progress (or regress)). When bench pressing and doing squats on the (Cybex) Smith Machine I had assumed that the bar weighed 45 pounds like a free bar does and added it to the total weight. It wasn’t until my most recent session (finished about 30 minutes ago) that I realized that the bar doesn’t in fact weigh 45 pounds…but weighs anywhere from 7 to 30 pounds, according to what I saw from a quick search. I should have realized that it wasn’t 45 pounds because it felt pretty light. Google says that the average weight tends to be about 15 pounds, but I have no idea.
I was also using the (Cybex) overhead should press machine and saw that the plates past 50 pounds went in 15 pound increments. Then I noticed the additional weight at the top, disabled by a pin. When I lowered it down on to the stack there was no number on it. Was it 5 pounds? 7.5 pounds? 10 pounds? Who knows?
How are people supposed to know how much weight they’re lifting if things aren’t numbered properly? They have these huge stickers that say everything, but they can’t put “bar weighs 15 lbs” on it?
I would mildly disagree. Knowing your numbers for a lift can help you estimate where you should be on related lifts. It can also help you very roughly gauge your progress compared to others. The mechanical advantage, friction, and other physical aspects of any given machine play a huge role for sure, but one can broadly make comparisons.
What does that mean? You are where you are. Where you should be is where you end up when you do your best. Knowing the absolute resistance on a machine doesn’t help with that.
If you mean comparing to other people, I strongly recommend against this. Compare against your past self, and only your past self.