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Tour Tech – The leading edge

By Matt Pacocha

Ridley’s new Dean time-trial bike


Belgian-based frame builder Ridley has completed two new models in time for this year’s Tour de France with the goal of putting Silence-Lotto’s top rider on the top step of the podium in Paris on July 27.

Anyone can hope, of course, but Ridley has the technological chops to back it up. Aside from Team Columbia’s prototype Giant, which we’ll look at in another piece, Ridley’s Dean and Noah are the big tech stories of this year’s Tour. And, unlike Columbia’s new time-trial bike, both Ridley models are slated for 2009 production.

Ridley owner Jochim Aerts

Ridley owner Jochim Aerts


Ridley owner Jochim Aerts said the brand began with one goal: “To have the fastest bikes in the world.” And he thinks Ridley has hit that mark with two new bikes that represent the culmination of four years of development: The Dean, a new time-trial bike, which Cadel Evans rode to third place in the Stage 4 time trial; and the Noah, a completely revamped bike for the sprinters and worker bees on Silence-Lotto.

Airfoil technology
Both new bikes rely on an aerodynamic technology licensed from Oval Concepts that Ridley has dubbed RFlow. Building upon Oval’s Jetstream, it reduces drag from the wheels by building airfoils into the fork blades and seatstays.

The Dean’s RFlow fork with airfoil technology licensed from Oval Concepts


Rflow accelerates the air passing over the fork using two airfoils in each leg and seatstay. The air passing over the outside edge of the first foil creates a vacuum around the upper axis of the spokes and tire that sucks air away from the wheel past the second foil’s outer edge; the spokes, remember, are passing in the opposite direction to the air, thus creating a large amount of drag. The airfoil technology is supplemented with additional aero features, including an Oval Concepts aero brake (made by Tektro) mounted behind the fork and frame sculpting that hides the bolt for the brake. The bike also features hidden cables and horizontal dropouts.

Oil mapping
Once the basic aerodynamic structures of the bikes were set through months of wind-tunnel testing, Ridley used a testing method called oil mapping to achieve further refinements. The goal is to eliminate turbulence and create laminar airflow, meaning to keep the air attached to the surface and flowing smoothly. Oil mapping provides a finer level of accuracy than taped-on streamers, and Ridley used what it learned to decide where to apply its R-Surface aerodynamic paint.

Texture — the dimpling used on skinsuits, swim suits, golf balls or a Zipp wheel — can help air flow smoothly across a surface. The concept is somewhat counter-intuitive, since the texture is clearly rough to the touch, but that roughness creates a small layer of air that adheres to the aero surface. The result, when the dimpled item is in motion, is a smooth boundary layer that allows air to move much more quickly than if it hit the actual surface of the bike.

Unlike other bike manufacturers, Ridley applies its texture using paint. The process, which is patented, is applied in the key areas defined using oil mapping on both the Dean and Noah.

Construction and materials
Ridley builds the bikes using its 30-, 40-, and 50-ton carbon fiber. The number refers to the modulus of the fiber, with the 50-ton being the highest and only used in key areas of the frame to add stiffness; 50-ton material makes up only about 5 percent of the frame. Both bikes use a monocoque molding technique on the front triangle and a new foam molding process for the detail areas, like the seatstays, fork blades and the headtube of the Dean.

Foam molding is a new process that allows Ridley to mold in fine details to the frame; it’s more precise than the bladder molding technique used in other areas. Ridley first makes an internal (reverse) mold from foam; it is dipped in latex rubber and carbon is layered over it. The foam mold with its accompanying carbon is then placed in a CNC clamshell mold and cooked, which melts the foam from inside as the carbon is cured. The new process sharpens the trailing edges of the airfoils so that they perform better aerodynamically. It also allows Ridley to hollow mold the nose of the Dean’s headtube.

Race tested by Evans and McEwen
The Dean was designed with circuitous ProTour time-trial courses in mind, and Ridley claims that it’s almost as agile as one of its road bikes. In addition to its slightly slacker angles, the new bike affords lower positions than its previous model. When Evans was asked what struck him about the new bike, he replied, “I’ve never had a bike that allows me to get this low before.” Since a rider accounts for 60 to 80 percent of aerodynamic drag, finding the best possible aero position is probably the single most important feature.

Ridley and Evans claim that in back-to-back tests on the track at a fixed 45kph speed, the Dean required 15 fewer watts than the earlier Chronus time-trial bike. Both Evans and McEwen raced the Dean during this year’s Giro d’Italia with good results. McEwen said that the new bike gave him a new confidence in races against the clock.

During a press conference to launch the new machines, he said: “Not being a time trialist, I feel like one [on that bike.]”

Ridley equipped the entire Silence-Lotto team with Deans for the Tour. McEwen has also been riding and racing the Noah since April, and he, Dario Cioni and Yaroslav Popovych are riding Noahs during the Tour. Evans, meanwhile, has stuck with his Helium road bike.

Ridley says the Noah is a huge advantage for the whole team, especially for McEwen in the sprints and the rest of the Silence-Lotto worker bees in the chase. The energy it saves McEwen can be applied to his sprints, but the rest of the team benefits as well.

Morgan Nicol, Oval Concepts’ marketing director, explained it like this: Evans will benefit the least from the new bike, because the team protects him from the wind. But his teammates – those charged with the job of protecting him – can do their jobs with less effort.

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