Specialized S-Works Roubaix SL2

OVERVIEW

NOTHING IS SMOOTHER AND FASTER

Tom Boonen and Specialized share some common goals. One of them is winning Paris-Roubaix. With its exceptional distance (over 250km / 150mi) and brutal pavé (cobblestone) roads, “The Queen of the Classics” is the toughest single day race in the world. Riding one of the very first S-Works Roubaix SL2 bikes, Boonen won the 2008 Paris-Roubaix in commanding style and reestablished himself and his bike as “The King of the Cobbles”.

The all-new Roubaix SL2 is a direct descendant of the prototype ridden to victory by Boonen. It retains the plush ride of previous Roubaix bikes but introduces an entirely new level of performance by way of superior lateral stiffness and torsional rigidity. The Roubaix SL2 delivers an unprecedented combination of speed, efficiency, handling and comfort. The ultimate Endurance Road bike has arrived.

Roubaix bikes are smooth, delivering superior vertical compliance thanks to uniquely designed seatstays, seat tube and curved top tube, as well as Zertz™ vibration damping inserts at the fork and seatstays.

Don't let the smooth ride fool you—the Roubaix SL2 is fast. The massive down tube, tapered head tube, oversized bottom bracket and chainstays, and fork with tapered crown and steerer boost lateral rigidity by 12%, torsional stiffness by 9% and rear end stiffness by a massive 21% for more efficiency, faster acceleration and sharper handling. All this was accomplished while reducing weight by 40g (56cm frame).

Roubaix bikes are stable. The bike that defines the Endurance Road experience features slightly more relaxed geometry than our Tarmac SL2 race bike, but retains the same trail dimension for neutral handling. With a longer wheelbase, ergonomic Body Geometry components, and a forgiving yet responsive frame design, we create the optimal body position for endurance rides.

TESTING

FROM MORGAN HILL TO PARIS-ROUBAIX

At Specialized, we test for two reasons: to make our bikes perform as well as possible and to make them reliable for a lifetime of hard riding. To achieve these two goals, we have developed the most accomplished crew of test riders (including Tom Boonen, Paolo Bettini and Davide Rebellin) and the most advanced test lab in the industry, run by the best engineers.

Many different types of tests are conducted to provide the most complete understanding of what Specialized bikes and components will encounter and endure when pushed to extremes, including:

Performance / Lab. Once the performance goals of the Roubaix SL2 were set, we had a quantifiable target. An initial frame design was crafted, new molds created and a first round of prototypes built. Lab tests were performed measuring stiffness and compliance in every key area and aspect of the frame. The goal was to deliver maximum performance in terms of ride quality, efficiency, and light weight.

Performance / Field. Extensive field testing of prototypes is performed by the world’s best professional riders and the fanatical staff at Specialized. Together, we log thousands of hours of real world riding in grueling conditions. Quantitative data from the lab is compared with the qualitative test rider feedback, and the frame design is revised. We repeated this process seven times in the 56cm size alone to achieve the performance goal set for the Roubaix SL2: Nothing is smoother and faster. The bike passed the ultimate test when Tom Boonen rode it to victory at Paris-Roubaix.

Safety / Durability. Safety and reliability are paramount concerns. Our engineering team pushes every frame beyond its limits in dynamic fatigue, ultimate strength, and impact testing. While most frames pass industry standard safety standards, Specialized has established its own parameters that exceed international requirements, including new CEN International Safety Tests.

FACT

FUNCTIONAL ADVANCED COMPOSITE TECHNOLOGY

FACT (Functional Advanced Composite Technology) defines our carbon development process, one that takes an integrated approach to engineering, material application, manufacturing methodology and testing. This integrated approach enables us to achieve the performance goal for the Roubaix SL2: Nothing is smoother and faster.

FACT IS “fact is” Chassis. The Roubaix SL2 FACT IS (Integrated Structure) frame is made with the largest monocoques possible while retaining perfect fiber alignment and uniform internal surfaces, resulting in reduced weight and increased strength and stiffness per gram. FACT IS integrates several different manufacturing methods to create an optimized structure that is incredibly light and stiff for efficiency, yet compliant for all-day and rough road capability.

The Roubaix SL2 employs the FACT 10r level of material, manufacturing method and final carbon layer. Like all of our frames, the Roubaix SL2 utilizes a sophisticated carbon layup schedule, comprised of multiple precision cut plies of carbon with different mechanical properties. The E390 carbon used liberally in the layup boasts a modulus of elongation of 390 GPa (gigapascals)—extremely stiff, but not overly stiff—just right for retaining vertical compliance, yet ensuring lateral and torsional rigidity. Because the seatstays are so crucial to vertical compliance, the Roubaix SL2 strategically utilizes E285 here, allowing more vertical deflection for a smoother ride.

REAR TRIANGLE

SUPPLE YET STIFF YET SUPPLE

Input from Tom Boonen compelled us to completely rethink the design of the rear end of a bicycle frame. His exceptional power output and sprinting prowess—combined with his ability to clearly communicate keen insight—led to the development of both the Tarmac SL2 and Roubaix SL2.

For the demands of the pavé of Paris-Roubaix, Tom asked that we create a frame that would deliver the efficiency of his Tarmac, with greater vertical compliance, so he would have more energy late in the race.

To achieve the vertical compliance, the seatstays are designed to act like a 3D spring. The stays curve in two planes, enabling them to compress when they encounter bump forces. As always, vibration damping Zertz™ inserts are strategically placed in each seatstay to filter vibrations before they reach the rider.

To ensure lateral and torsional rear end stiffness, the Roubaix SL2 (like its brother, the Tarmac SL2) features seatstays that form a triangle between the brake bridge and the seat tube. This triangulation sets up the entire rear end to be laterally and torsionally rigid, boasting a 21% increase in rear end stiffness compared to the 2008 S-Works Roubaix. The wide, triangulated stance required a specifically designed and tooled seatstay for each of the six Roubaix SL2 sizes and ensures maximum lateral rear end stiffness. When combined with the carefully engineered materials and design of the Roubaix SL2, the perfect balance of vertical compliance, lateral stiffness, and torsional stiffness is achieved.

MID-SECTION

POWER TO THE PAVÉ

The midsection of the Roubaix SL2 is engineered as a system to maximize stiffness. Greater stiffness at the bottom bracket allows more efficient and direct power transfer from the rider to the rear wheel. Improved acceleration and better use of your energy are the result—extremely valuable when covering vast distances and powering through rough terrain.

The down tube, BB shell and seat tube employ a carbon-centric design. By eliminating sharp edges in the structure that have not been optimized for carbon fiber, we have exceeded the stiffness of bikes with wider BB shells and larger diameter tubing.

The seat tube is another noteworthy piece of engineering. The asymmetrical design provides adequate clearance for the crank and drivetrain on the drive-side, but flares outboard on the left side of the bike to maximize lateral rigidity at the BB. The effect is much like taking a wider stance with your feet to keep you more stable.

Chainstay size was increased by 33% and features a refined shape to position maximum material where it strategically enhances stiffness. What is the result of all of these design, material and manufacturing details? The Roubaix SL2 delivers the ideal balance of stiffness and compliance—the perfect bike for long, fast rides on challenging roads.

CRANKS

TOTAL INTEGRATION. MAXIMUM PERFORMANCE.

Nothing is stiffer and lighter than the integrated FACT carbon crank and bottom bracket. Because we control the design of every chassis that features a FACT carbon crank, we’re able to optimize both the frame and crank for maximum efficiency and performance.

An oversized bottom bracket shell houses a pair of large diameter bearings directly in the frame for maximum torsional rigidity and eliminates redundant bottom bracket hardware. Total integration also allows us to employ a dramatically oversized two-piece bottom bracket spindle, one that saves weight and boosts efficiency under peak loads.

Crank arm stiffness is improved through a hollow and more efficient 'D' shape. The two crank arms are attached in the middle using a Hirth coupling for maximum stiffness. In addition, the carbon fiber is continuous from the pedal threads to the alloy spindles at the Hirth coupling. Shifting performance is improved by refining tooth profiles, reengineering the spider (to increase stiffness) and adding a proprietary 3-19 Ni Boron plating to the chainrings.

FRONT END

FORWARD THINKING.

Every aspect of the Roubaix SL2 was developed through an integrated approach. In designing the front end, all conventions and constraints were abandoned, and our engineers were free to develop the fork, head tube, top tube, down tube and headset from scratch to achieve our performance goals. The result? Nothing is smoother and faster.

To maximize stiffness and minimize weight, we employed a carbon-centric design. The fork’s steerer tube tapers from 1-1/8” at the top, to 1-3/8” at the crown. This first ever 1-3/8” lower bearing is the perfect balance for retaining vertical compliance, while increasing stiffness. The design not only enhances steering precision and torsional rigidity, it maintains optimal fiber alignment by eliminating sharp angles between the steerer tube, fork crown and blades. This is essential to unlocking the strength and stiffness potential of carbon fiber.

An oversized head tube enables the use of a larger down tube and optimally shaped top tube. These precisely engineered, shaped and frame size-specific tubes give the SL2 maximum torsional rigidity for improved steering precision and out-of-the-saddle upper body power transfer, yet the improved stiffness does not compromise vertical compliance.

The interface between the fork and head tube is also a unique example of the advantages of integration. Because we are in control of the frame, fork and headset design, our engineers were able to align force transferred from the fork directly to the point that the down tube meets the head tube.

Intelligent front-end design details enabled us to use less material and actually increase the strength and stiffness of the bike. Together, these key features of the Roubaix SL2 make it the ideal endurance road bike with the perfect blend of performance and compliance.