Hammer strength incline

[ajgen]

The other day I did a chest routine where I did

machine pec fly 5 x 10-15 - 140 (pre-fatigue)

Bench press 3 x 8 - 185 lbs

then went I went to the incline press hammerstrength machine, I added 3 plates on each side and was able to bus out a full 3 sets of 8 reps.

That's weird to me because I can only do 160 lbs on incline barbell, so why is there such a huge difference in the weight?

Does gravity and the use of stability muscles make that big of a difference? Or is there some sort of mechanism in the machine that allows people to move more weight?