Ridley Noah 1204A Frameset
While most bicycle companies would be content to rely on their tubesets for an aerodynamic advantage, Ridley's research and development on their flagship Noah go far beyond tube shapes and bike geometries. The latest generation of Ridley's groundbreaking Noah shares the same proven aero features as its earlier iterations — including an aero downtube, internal cable routing, an aero seat tube that extends into an integrated seatmast, and a deep rear wheel cut-out. What sets the Noah apart from other aero bikes is its use of Ridley's R-Flow technology. As we all know by now, drag increases exponentially with airspeed, which means small changes to reduce your drag will have a disproportionately positive impact as your speed increases. R-Flow technology focuses on one specific issue of bicycle aerodynamics.
According to Ridley, your wheels produce eight times more drag where they pass through your fork and seat stays due to the turbulence of the colliding air masses there. The Noah is built to minimize this drag thanks to its use of long, slotted airfoils built into both the fork legs and the seat stays. These airfoils redirect oncoming air away from the turbulent areas near the wheels.
The story of the Noah doesn't stop at R-Flow. Ridley used oil mapping in the wind tunnel to isolate spots of turbulent airflow. And where structural limitations kept them from re-sculpting the frame, they applied a textured surface treatment for boundary layer control. Ridley calls it 'R-Surface,' also affectionately referred to as 'aero paint.' These thin strips of texture are amazing; they purposely trigger a known amount of turbulence that re-energizes lost boundary layers, ultimately re-establishing laminar flow and minimizing drag. In other words, they carefully create an airflow mess in order to make an unprecedented cleanliness. Airflow control is why you see vortex generators on aircraft wings, and why you see dimples on golf balls. And it's exactly what Ridley does with their R-Surface paint.
The Ridley Noah comes in five sizes from X-Small to X-Large and is available Black/White/Red. Given its semi-compact geometry, we strongly suggest that you focus on the effective top tube length as you make a determination of the proper size. The Noah FB requires a press-fit BB30-compatible bottom bracket and a braze-on front derailleur. It includes a 120 gram seat clamp assembly that allows an 18mm range in saddle height and comes with 1mm micro-spacers for small adjustments. Ridley also offers an aftermarket clamp that provides 40mm of height adjustment. With the frame weight at less than 1200 grams, comparisons with other bikes are favorable for the Noah, as you save some weight for the seatmast/clamp assembly. In the end, there's virtually no weight penalty. Given the aerodynamic upsides of the Noah, the fact that weight is a non-issue makes it that much more appealing.