The Tarmac gets kudos as a classic road racing frame. It's stiff, light, aero, and fast. The Tarmac has won classics, Tours, and World Championships, with a devoted following among the folks who love to both casually ride and race.
Since 2004, the Tarmac has been Specialized’s premier road bike. It began as the E5 in 2003, half carbon, half aluminum, then the SL1 which debuted in 2006 as the first all-carbon Tarmac. The SL2 benefitted from Classics superstar Tom Boonen providing input. The SL3 and SL4, lighter and stiffer still, quickly followed. Then the SL5 became the first Tarmac with size-specific tubing shapes and layups, obtaining over 100 pro wins in three years.
S-Works is the pro-level designation; the frames that Specialized provides to its pro riders. The features and geometry of any S-Works model within a platform are typically the same as the other models, just with a lighter, stiffer, more-expensive carbon-fiber layup. Few “need” an S-Works Tarmac, but few can turn down the oh-so-amazing ride it provides.
Below S-Works, the Tarmac has Pro, Expert, Comp, and Tarmac. All have identical geometry numbers.
When Specialized debuted the Tarmac SL7, they also retired their Venge platform. The Venge had been their premier aero road bike, but with the SL7, they had a bike that was more aero than the original Venge Vias. The SL7 is also as stiff as the SL6, with a minor weight penalty.
For many roadies, it’s easy to see the Tarmac SL6 living on and on. Lighter than the SL7, there’s even a rim-brake version with direct-mount rim brakes. Climbers and weight weenies will love this bike with its impressive weight and fantastic climbing ability.