For most exercises, I've found that when going from dumbbell to barbell, it's at least double
your dumbbell weight. ie, I can curl 40 pounds in each hand, with a bar, I can do about 90.
I bench 40 in each hand, and do about 125 with a bar. So there I guess it's triple. Just
find a bar, a bench, and keep loading weights till you can't do more than 8.
