When Orbea set out to build an aero road bike, they decided to define their mission as building an aero road bike that is still very much a practical road racing bike. They succeeded by taking a different route to their goal. The Orca Aero OMR is aero, stiff, and integrated.
First, a word on their geometry. The Orca Aero shares head angles, seat angles, bottom bracket drop, chainstay length and fork length with the identically sized Orca OMR. Reach is nearly the same, though stack is a bit different, and wheelbase a bit longer. Overall, it rides very much like the standard Orca, but with a bit more stability, not a bad thing for a bike that is designed for high speeds.
In terms of aerodynamics, they benefitted from their collaboration with the aerodynamicists at Mondragon University, and were freed up by the UCI, which recently relaxes their requirements of aspect ratios of frame tubes. The UCI used to dictate that bikes had no more than a 3:1 ratio, meaning that no tube could be more than three times longer than it was wide. As a result, the fork is, in sections 3.8:1, which allows the fork to better control the airflow around it. And this is in addition to the oversized tapered steerer, bumping up from 1 1/8” to 1 ½”. Many aero bikes skimp on the taper to minimize frontal area. Orbea believes that stiffness at the crown is worth the penalty, as the bike steers better. If you compare The Aero fork to the OMR fork, you’ll find it is 4w faster at 50kph (this speed is the standard measure for aerodynamics), resulting ins a savings of 8.4 seconds over 50km.
They also took a micro-sectioning approach to their frame, adjusting shapes over the course of the tube lengths to maximize aero impact. That’s why they went for a multi-shaped wide and shallow Kamm-Tail-like design for the downtube, which works at both smoothing the air that has passed over the front wheel and protects the water bottle. They even went with three bottle posses on the downtube. They call it Orbea MMS or Multi Mount System. Use the lower mounting points for a single bottle, the upper if you’re running two bottles.
The seat tube lower section is designed to shroud the rear wheel. Joining the seat stays below the top tube is both aero and adds a little compliance. The seat stays are shaped to thin as they travel from the seat tube to the rear axle, a nod to both aerodynamics and compliance. Even the seatpost is redesigned, with an oval shape that can be run forward or backward for either 23mm of setback or for forward, tri’-style positioning. The seatpost clamp sits flush with the top tube, and they even designed a rubber cover, to both further improve aerodynamics and keep debris out.
The wide BB386EVO bottom bracket shell is part of the aero package, as is ICR, Internal Cable Routing, which is based on a single plate at the top of the downtube. It can handle mechanical as well as wired electronic and wireless electronic shifting. The brakes are direct mount, which isn’t as aerodynamic as fully hidden integrated brakes, they not only stop better, but the cable routing is smoother for less friction, and servicing is much, much easier.
All told, their aero work saves 27 watts for the complete bike. That’s 27w saved at 50kph, resulting in s time savings of 82 seconds over 50km. The savings at lower speeds won’t read as dramatic, but they add up even more—the more you’re riding, the more they add up. (BTW, if you go with a complete bike, it comes with an integrated handlebar/stem combo, which is worth another six watts of savings.)
The shaping also makes the bike stiff. This is the stiffest Orbea in the lineup, which should interest bigger riders as they benefit the most from added stiffness.
The bike comes with a front derailleur hanger that allows you to install chainrings up to 56-teeth on the outside, 46 on the inside. The maximum tire width his 28mm, just like the Orca OMR. Big tires are comfortable, and with many wider rims, offer little aero or rolling resistance penalty.
The Orbea Orca Aero OMR road bike keeps aero bikes road friendly.