Bike fit / correct riding position

Watch Sunday in Hell - Eddy Merckx is constantly tinkering with his bike. Your flexibility varies from day to day so if you know what you are doing you can improve your performance with minor tweaks. A cyclefit or similar will get you into the overall sweetspot for your comfort and performance. They will also set you according to your preference (eg more comfort or more power) though cyclefit tend to go more for comfort.

There's a piece in the Andy Pruitt book about Merckx senior and why he was always tinkering with his bike setup. Longer thigh bones than normal if i remember correctly.

But I am weird.

+1 :)