Usually depends on the age of the machine. If it is fairly new then the counterbalance usually makes the bar weigh 15 pounds instead of the standard 45. If it is an old machine, then sometimes there is NO counterbalance and it weighs 45 lbs. You can usually tell simply from the weight of the bar without any weight.
Today I can do what others will not so that tomorrow I will do what others cannot.
The difference between winners and losers is that winners do things that losers don't want to do.
I read somewere they are usually 16-25. But like they said it all depends on the style and how the counterweight is set.
Just going from one to the other in our gym you can tell there is a weight difference.
"When I use the word intensity I mean the ability to continue past and through the pain barrier where your mind pleads to stop and in fact convinces your body that you have hit failure, but you push through. How far you push through that barrier is the level of intensity with which you train." -- Twin Peak