Umm, I'm looking at the weight from 170 lbs to 60 lbs in 6 sets and something doesn't add up? I mean, it's 170 lbs on the first set and I'm trying to wrap my head around this.

Thanks guys for all the replies... I tried to keep my rest time not more than 40secs...

The reason I drop a lot is because, when I tried heavier weight, I can't even lift them for more than 3 times I suppose, my arm just wont get str8 after the 3rd rep or even 2nd... Its like my mind is not commanding the the muscle. So I try to do more lighter weight to make my muscle use to it...