GreenPlease wrote:
Same hip angle or same saddle height? 165s on my TT and 175s on my F-Si. I would think hip angle would be more important.
Same hip angle is most important. Close to same saddle height is next. How upright the aero position on a fat bike or mountain bike is almost irrelevant other than when transfer to real TT bike the entire position rotates forward, meaning a bit more weight on the upper body and marginally different muscle recruitment in terms of how the weight of your leg interacts with gravity on the power phase and recovery phase, but that's all miniscule compared to hip angle and saddle height.
I have a spin bike in my basement with saddle nose 3 inches behind BB and bars 2 inches higher than saddle, but hip angle is actually more closed than my TT bike....no issues going from that to the TT bike. I believe it was Rapp who had his road bike saddle position slammed so far back that when he was in the hoods it was same hip angle as TT bike and the drops was more closed, and then going to TT bike was a breeze. The upshot was that riding the road bike with the butt so far over rear wheel, it's super stable and safe in traffic etc etc while getting almost all the adaption needed to go to TT bike.