Hitting the Tarmac with Specialized for 2008

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The new Specialized S-Works Tarmac SL2(Image credit: James Huang)

Tech feature: Specialized 2008 road lineup, July 2, 2007

Another year brings another Specialized product introduction, which now slides over a couple of European countries to Navacerrada, Spain, just outside of Madrid. As usual, Specialized's engineers and designers have been steadily beavering away over the last year (or more!) to bring yet another impressively overhauled lineup for 2008. Cyclingnews Technical Editor James Huang covers road bikes and equipment this time around, with off-road and women's equipment (along with other stuff!) to follow in the days ahead.

We already managed a sneak peek at the new Specialized S-Works Tarmac SL2 captained by Tom Boonen (Quickstep-Innergetic) during the Critérium du Dauphiné Libéré, and the good news is that Specialized has now officially introduced the bike as a production model for 2008. The new bike still isn't quite exactly the same as what 'Tornado Tom' rides (Boonen's machine features a fully custom front triangle with a longer head tube and a unique fiber lay-up schedule with additional plies for added rigidity), but should still offer the same basic message and changes relative to the extant S-Works Tarmac SL which will continue to be available.

The resultant FACT IS (Integrated Structure) chassis uses more high modulus carbon fiber and is built with a new FACT 11r construction method that blends monocoque and Specialized's Az1 wrapped-joint technology. Bottom bracket and torsional rigidity are gained through an enormous down tube, exceptionally tall chain stays that take a straighter path from the bottom bracket shell to the carbon dropouts, a square-profile seat tube, and a wide and flat top tube.

Up front, the new SL2 carbon fork now flares from 1 1/8" at the stem to 1 ½" at the crown for more precise handling, increased strength, and lighter weight. As an added benefit, the similarly flared head tube also allows for a larger junction with the down tube for even more stiffness. Frame designer Luc Callahan also shifted the lower headset bearing up inside the head tube by 12mm for improved front-end impact and fatigue strength as loads are now transferred directly into the wall of the down tube.

In spite of the roughly 30% increase in bottom bracket stiffness (according to Specialized), the new Tarmac SL2 somewhat miraculously is also reported to offer 10% more vertical compliance than the previous model, making it more efficient and more comfortable. To sweeten the pot, the SL2 is even about 100g lighter than the SL. Claimed weight for a 56cm bare frame is 952g; the matching fork is 350g with an uncut steerer.

Up front, the approaching air first sees the narrow 1" alloy steerer on the N'Aero carbon fork (and matching hourglass-shaped head tube) which incorporates a unique crown shape and leg profile. Small 'speed gussets' (whose name cleverly implies that they are structural elements to satisfy UCI requirements) located on the down tube just aft of the fork are said to smooth airflow passing through the crown, while the steeply sloping top tube supposedly does the same job for air coming off the back of the bar and stem.

Specialized also incorporates a proprietary braking system for the new Transition which uses a more aerodynamic center-pull dual-pivot configuration (think old U-brake) and aero-sculpted calipers. Naturally, all cables are routed fully internally, but mechanics can breathe a sign of relief: a set of four pre-installed nylon tubes route each line to its respective location so no fishing (or cursing) will be required. Full housing is used throughout for ease of assembly and protection from corrosive sweat, water, and grime. What's the fourth tube for, you ask? To route your SRM power meter wire, of course! Splicing is required, but it still provides a clean and slippery appearance.

We only managed to sample a single day on the new SL2, but the difference in overall feel between it and Specialized's S-Works Roubaix SL (which is no slouch in its own right) is still immediately obvious nonetheless. The new Tarmac doesn't quite possess the Roubaix's ultra-buttery ride (it's not far off, though, at least on smaller stuff), but the stiffer chassis is noticeably more responsive in all conditions, be it climbing, descending, climbing, sprinting, or climbing (it's quite hilly here!). Turn-in is also dramatically quicker, and the entire machine exudes a level of overall directness that should undoubtedly satisfy racers.