I have been ridding for just over 2 years, I have always been super flexable. I can't seem to get my back flat, it bends just below my ribs(on the back). It doesn't hurt at all. I recently rode a century and alot of it was pace-line in the drops, and still no pain. My fixie is to small and has over a foot of drop and the pressure on my hands is the only pain. I have read about lung capacity change, but my chest seems to stay relatively open even with drop. the first bike fit i got sat me upright w/ bars way above seat. (he said my back would hurt.) Right now i have around 3 inches of drop, and the bike is super comfortable.
I am wondering if anyone has any experience with this. Thanks

I have been ridding for just over 2 years, I have always been super flexable. I can't seem to get my back flat, it bends just below my ribs(on the back). It doesn't hurt at all. I recently rode a century and alot of it was pace-line in the drops, and still no pain. My fixie is to small and has over a foot of drop and the pressure on my hands is the only pain. I have read about lung capacity change, but my chest seems to stay relatively open even with drop. the first bike fit i got sat me upright w/ bars way above seat. (he said my back would hurt.) Right now i have around 3 inches of drop, and the bike is super comfortable.
I am wondering if anyone has any experience with this. Thanks

Not sure exactly what your question is. Are you concerned about not having a flat back? You should look at pictures of Lance Armstrong on his TT bike - not a flat back. A lot of this is personal physiology, but tilting your pelvis forward tends to flatten the back. The downside is that it may put more pressure on some tender bits and cause numbness of the kind you don't want.

all other aside, is this bend in my back bad long term.

Cyclists tend to develop strength along the front of the body, and inflexibility along the back side of the body.

Stretching and weight training can compensate for this.

But if the riding position works for you, then it works. Typically, the more core strength you have the lower you can ride in the drops. The more power you put into the riding, the lower you can sit in the drops.

But there's a zillion issues going on with regard to position. Generally, if you're not going numb and having shooting pangs down the limbs, your position is just fine.

Howsomesoever . . . Stretching, flexing, and compensating weight training for "balance" are good ideas.