Fourth generation of US company’s flagship road frame to be ridden by a number of riders in the Tour de France

specialized tarmac sl4Specialized has unveiled a new version of its new flagship Tarmac frame, the SL4, which most of its sponsored riders will be riding at the Tour de France this weekend. The new frame is both lighter and stiffer than its predecessor, although it will not be ridden by Specialized sponsored Tour favourite Alberto Contador (Saxo Bank-SunGard).

The SL4 has been made with even more torsional stiffness than the SL3, which was already one of the stiffest frames out there, but Specialized has taken care not to sacrifice ride quality. The super oversized head and down tubes “wrap” around the top and bottom of the new King Cobra head tube, which, thanks to the stiffening of the junctions, has a reduced 1 3/8” lower bearing, compared with the 1 ½” on the SL3.

The SL4 frame is made up of four monocoque sections, including a one piece bottom bracket and chainstay unit, with “carbon fibres running continuously from tube to tube within each section”. It has a strategic use of ultra-stiff pitch fibre, internal ribbing and “tweaks” to the seatstays and fork. The frame is 19% stiffer than the SL3, and Specialized claims it leads the way in terms of its stiffness-to-weight ratio.

While Specialized seldom quotes figures of frame weight, it claims that the frameset module, which includes a carbon S-Works chainset is the lightest out there at 1995 grams.

While many of Specialized’s sponsored riders – on the Saxo Bank-SunGard, HTC-Highroad, and Astana teams – will doubtless be riding the company’s Venge frame, which was launched back in March, the following will be astride the new Tarmac SL4: Peter Velits and Tony Martin (both HTC-Highroad), Alexandre Vinokourov and Roman Krueziger (both Astana), and Ritchie Porte (Saxo Bank-SunGard).

The highest profile name to be riding a Specialized bike will, of course, be Contador, who has already won this year’s Giro d’Italia aboard the SL3. Specialized has informed VeloNation that, since he has not had much time to acquaint himself with the new SL4, he will be staying on the frame he knows.

VeloNation has also been informed that feedback from sponsored riders on the “Project Black” frames will be passed to Formula 1 motorsport team McLaren, which created its own version of the Venge. This feedback “may or may not be used” in the development of an SL4 McLaren.

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