EB14: New Pro-level Noah SL Aero Road Bike From Ridley

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With feedback from their Pro-Tour sponsored Lotto-Belisol team, Ridley has developed an evolution of their Noah FAST aero bike concept into the professional-level Noah SL. The Noah SL fits in between the 2 bike the pro-team picks from, the Helium and Noah Fast, pulling benefits from each to create a bike to keep weight low, while still giving riders the aero advantages they’ve come to demand for the fast and bunch sprint races.

Come past the cut for detail on the development and the tech on the new bike.

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Ridley began the development of their FAST concept in 2010, with a move to aero tubing profiles and building the brake systems into the frame and fork to remove them from the wind. Since that time they have built the FAST concept into the Noah aero road and Dean TT/triathlon bike lines to benefit from incrementally improved aerodynamics.

Ridley carries over some of the top-end aero tech into the SL, while cutting a bunch of weight and making it more friendly to the pro team race environment, in part by carrying over the chainstays and dropouts from the Helium SL. What comes over for aero benefits are their F-Tubing profiles and the F-SplitFork, while the frame does with standard brake mounting to aid servicing.

The F-Tubing’s main goal is to keep the air flowing directly over the tube’s exterior. Ridley claims that by inmolding grooves into the leading curves of their truncated NACA profiles, micro turbulence is created that allows a boundary layer of air to form and to ’stick’ to the tube, allowing a smooth laminar airflow hugging the profile and off  the trailing edge.

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Ridley’s testing shows the F-Tubing yielding a 7% average aerodynamic drag reduction across many yaw angles vs. the widely used truncated NACA profile.
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The F-Splitfork is also updated with a more improved smooth transition to the frame downtube, and a headtube design more integrated to flow smoothly into the toptube, all the way to an integrated seat clamp to reduce airflow disturbance.
A more compact rear triangle with dropped seatstays has several advantages beyond aerodynamics. First, it’s lighter because there’s less material. Second, it’s stiffer lateral for better power transfer. Third, it can be made more comfortable since forces from the rear wheel are dissipate first by the seat tube rather than driving it directly upward to the seat post. As for aerodynamics, the benefit is that it helps hide the rear brake. Surprisingly, Ridley keeps the rear caliper in its traditional place rather than put under the bottom bracket, making it much easier to service (especially for pro team mechanics leaning out of the support car at 50km/hr) and keeps the brake cleaner overall.
A big plus is that the bike is designed around 25mm tire clearance on wide aero rims. Ridley’s project manager actually says that is a pretty conservative statement, with 28mm tires clearing on the bike, something that we think is probably true just from looking at the room around the brake bridge and at the chainstays.
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The bike sits in a premium spot between the Helium SL, their lightweight race bike, and their Noah FAST, their more standard aero road bike. For Andre Greipel, on hand for the product launch, it could easily become his single race bike on most days, where he can reap  the aero benefits, and light weight, while still meeting his super sprinter stiffness requirements.
With this development the aero road line for 2015 includes the Noah FAST with integrated brakes and seat mast, with the Noah SL somewhat in the middle, and the Noah ISP with regular brakes but an integrated seat mast. As for weight the goal was to keep the bike under 1kg, and the result is a claimed 980g for a size M. How that compares to the FAST system apples-to-apples is that the SL is 200-250g lighter, all things being equal. (The FAST is ~1200g with brakes integrated, and the FAST fork is ~450g with brakes integrated.)
Ridley is very committed to developing their bikes for the pro tour peloton, with the new Noah SL a bike truly engineered for teh pro team. This commitment is apparent most obviously in their commitment to the Lotto team, the longest running sponsor in the ProTour, an their newly signed 6 year sponsorship of the renamed Ridley-Lotto-Soudal for 2015-2020, the longest contract commitment yet in the ProTour. It was also seen on the day Tony Gallopin unexpectedly took the yellow jersey  at this year’s Tour, and Ridley quickly jumped to work with the CEO driving overnight to give the frenchman a custom yellow bike to ride on Bastille Day.

Comments

Psi Squared - 08/26/14 - 9:32pm

I think lessons are in order so that people will understand that there are multitude of NACA airfoils: 4-digit, 5-digit, 3-digit camber lines…….. Ridley’s new airfoil likely fits or fits very closely a NACA generated airfoil with the exception that Ridley has added boundary layer control features.

Quickie - 08/26/14 - 9:33pm

I think I need a lesson just to understand your lesson.

Will Hilgenberg - 08/26/14 - 9:51pm

And here is your lesson for your lesson Quickie;
http://en.wikipedia.org/wiki/NACA_airfoil

And Psi Squared. I agree completely. Although not all profiles are going to fit the NACA profiles. Especially at tube junctures.

Xris - 08/26/14 - 10:34pm

Screw lessons, ride faster

Guy - 08/27/14 - 12:16am

I agree, apart from the truncation the overall shape of the airfoil could be easily modeled onto a 5 digit. I think they are referring to a traditional 3 digit of old, which they really shouldn’t be talking about because bike manufacturers haven’t really used those for years… But I appreciate the consideration.

Mario - 08/27/14 - 4:01am

Why not tuck the brake behind the fork?

Tomi - 08/27/14 - 8:40am

@Mario because studies always showed it didn’t provide any advantage while being less convenient.

Greg - 08/27/14 - 10:30am

@Xris
Those who know talk about it, those who don’t ride faster.

WK - 08/27/14 - 2:37pm

Golf ball concept

John M. - 08/28/14 - 3:37am

It’s actually hard to believe that anyone is using ancient NACA airfoils anymore, especially for low speed applications like bicycles.

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