Originally Posted by
caloso
Before you change anything on your bike ask yourself whether you could be bending your elbows more.
This. No need to make any changes to your bike to start, just lower your position. Have someone take a video as you ride by and figure out where your head needs to be to get a flat back, then practice riding in that position and see how it goes.
You'll often be faster riding on the hoods with your forearms parallel to the ground rather than riding in the drops.
Here are some tips from Gerard Vroomen (Cervelo founder):
Body position vs bar height – part 1