2016 Cervelo R5 Dura-Ace 9000 58

Internal cable housing looks clean and can keep your bike's cables running smoothly for a long time. But there's a second reason to run cables inside the frame. Aerodynamics. The internal routing is part of the 7.4 watts of savings this frame nets you over the previous R5. A bigger part is the better sculpting of the various frame tubes leading edges. By putting the earlier R5 into the wind tunnel, they found its tubes fairly aero, and they went about figuring how to reduce drag without compromising ride quality. And that's what they did, by sculpting the leading edge and changing the corners of the trailing edge, they get the same ride with the wind seeing less tubing.The ride balances compliance, with ultra-thin seat stays and a fork that's been designed to give more in the vertical plane, with stiffness. That stiffness can be found with laterally stiffer fork, an oversized tapered 1 3/8" lower steerer tube, a diameter to balance both rigidity and ride quality, and a head tube that's