When the S-Works SL6 Tarmac was launched last year, it introduced a few new design innovations Specialized had been developing for the previous six years. The result was a lightweight bike with crisp handling, advanced aerodynamics, and ride compliance tuned for each frame size. As nice as that bike is, the version we all knew would eventually arrive is finally here in the S-Works Tarmac Disc.
The newest edition of the Tarmac line wasn’t just refitted to wear hydraulic stoppers. Integrating the disc system required an extensive revamp of the frame with an extra 200 individual pieces of carbon added to the layup. While the geometry and tube shapes were mostly retained, the internals of the frame were radically altered as to not sacrifice weight or aerodynamics. According to Specialized’s Win Tunnel expert, Chris Yu, the new Tarmac Disc is as sleek as the first generation Venge.
At 800 grams for a size 56cm in the lightest paint scheme, the disc model weighs no more than the rim brake frame. The fork on both models is slightly heavier than some might expect at 338 grams but was designed to offer the optimal ride qualities rather than low gram count. The fork plays a major role in defining the Tarmac’s overall ride feel with rigidity a primary design objective. As explained by Chris Yu, “The stiffness of the fork contributes to the Tarmac’s precise race-inspired handling and improves rider confidence during hard cornering and braking.”
As a complete bike, the Tarmac Disc weighs just 14.65 pounds putting it just below the UCI legal limit. The addition of the disc brakes does add a modest amount of extra weight over the rim brake model which is .65 pounds lighter for the same size 56cm frame. The extra weight is distributed evenly throughout the bike with reinforcements to the rims and hubs. A few extra grams are attributed to the one major standout feature of the new bike, the much anticipated S-Works Carbon Power Cranks. More on those later.
Like the rim brake bike, the new Tarmac was designed with geometry data gathered by the fit experts at Retul. Both versions are identical with regard to frame metrics and sizing, save for one minor difference. Whereas the rim bike has a chainstay length of 405mm or 410mm depending on frame size, all disc bikes have 410mm stays. Complete bikes are available in men’s and women’s models, both using identical frames – only the bars, cranks, and saddles are gender-specific. There are six men’s sizes (49, 52, 54, 56, 58, 61) and five for women (44, 49, 52, 54, 56).
To maintain the optimal ride attributes initially achieved with the Tarmac Rim, the disc frame was also designed to incorporate Specialized’s Rider-First Engineered philosophy. Each frame size is not only built with a specific geometry, but tube shapes and layups also vary per size. A Tarmac Disc frame consists of more than 500 individual carbon “plies,” each placed where it is needed most based on size. One essential element to the plush road feel is attributed to the new D-shaped seatpost. The upper 100mm of the layup was tuned for increased rearward compliance.
In keeping with tire trends, the new frame was shaped to accommodate up to a 30mm tire, although complete bikes will ship with 26mm Turbo Cotton tires fitted to CLX 50 carbon disc rims. Aerodynamics at the front wheel is improved with a Flush Axle System which eliminates the lever. The included and optional 6mm, 12×100 flush bolt also drops the weight by 30 grams over the standard RWS lever. Standard 12×142 rear axle spacing leaves ample options open for aftermarket wheels.
Available now, the S-Works Tarmac Disc sells for $11,000 for the complete bike built with Shimano Dura-Ace Di2. That includes the all-new S-Works Carbon Power Cranks and carbon aero wheels. Framesets sell for $4,500 to $5,000 and include CeramicSpeed BB30 bearings, headset, seatpost, seat clamp, and necessary cable routing accessories.
