Originally Posted by
burnthesheep
I went 175 to 165. It's actually the difference, times two. The way I see it.
You gain 10mm in aero by raising the saddle for the 10mm less at BDC. Then you gain 10mm towards hip angle at TDC.
I may be wrong on that, but feels that way to me!
Not sure I understand the "times two"
. If you gain 10mm in aero, it means you did not raise your stem so your hip angle is more pronounced than it was at BDC. But because your crank arm is 10mm shorter, hip angle at TDC is probably similar than what it was with the 175 crank. To me the real advantage is that you can decide what to do with the 10mm (aero, hip or split between the two).