80 kg today!
So I went for the free weights. The bar weighs 20 pounds and I put a 50-pound disc on each side and then lay back on the bench and lifted it. That was 120 pounds. It was difficult, but more than that it was scary. I kept imagining me tilting it and one of those huge discs falling off or somehow I don't get it back into the cradle and it decapitates me.
There should have been clamps to secure the plates to the bar to prevent them from sliding off. I suggest trying it again, next time asking a guy at the gym to spot you (if you can't get it into "the cradle" your spotter will lift it for you, preventing injury). If you have the weight secured and a spotter, you'll be able to lift safely, thereby allowing you to figure out how much you can actually bench.