What do you guys think about going with a shorter crank? I rode 170's when I raced last, which felt better than 172.5 (which I currently have), but I'm debating on trying some 165's to open my hip angle even more, and get my back even flatter (I would have to raise the seat 7.5mm, and keep the bars where they are). I'm interested to hear if you guys have tried this.