2015 Specialized_Tarmac S-Works Disc Frame

The new Specialized Tarmac disc-ready frame, MSRP $5,500.

It's perhaps not the most novel concept, but for the latest version of its popular Tarmac race bike, Specialized is hanging its hat on the notion that different sized riders essentially need different bikes. Enter "Rider-First" engineering where every sized frame (six in all) was developed independently based on data gleaned from on-road tests that measured forces into various parts of the frame. In turn this data was used to modify the carbon lay-up process with the end goal being that a rider on a 61cm bike would have the same (presumably joyous) experience riding the new Tarmac as a rider on a 49cm.

Silly marketing speak aside (Would you buy a bike that wasn't first engineered for the rider?) the idea certainly makes sense. Taller, heavier riders need a stiffer bike than someone a foot shorter and 50 pounds lighter. This notion was born out in testing, claims Specialized. With the previous Tarmac, big guys wanted something more responsive (stiffer), while shorter riders complained the bike was too stiff. Now just like Goldilocks' porridge, everything is just right, says Specialized.

Of equal significance is the addition of a new disc-brake equipped Tarmac. This is one of the first times we've seen rotors on a road race frame, which heretofore has been problematic because of the shorter chainstays on these stiffer, more nimble rigs. The combination of those shorter stays and wider rear wheel spacing can cause chainline issues. Specialized addressed this by moving its cassette inboard on the Roval wheel hub that comes with the new bike. Now, though spacing is 135mm, cassette spacing is representative of traditional 130mm spacing.

Specialized opted against using thru-axles, sticking with standard QR. But it is employing more rigid end caps. The new frame also has a recessed seatpost collar, which will allow the 27.2mm post to flex more, enhancing comfort.

2015 Specialized Tarmac Disc

The new Tarmac disc with Shimano Dura-Ace Di2, MSRP $9,500.

The top line S-Works Tarmac Disc will retail for $9,500 and come spec'd with Roval Rapide CLX 40 SCS Disc wheels, Shimano 785 hydraulic disc brakes, and a Shimano Dura-Ace Di2 drivetrain. An S-Works model with rim brakes and SRAM Red will run $8,250. The S-Works Tarmac Disc Frame will sell for $5,500, while a traditional rim brake frameset will run $3,750.

For more info visit www.specialized.com. And here's a promo video further explaining the ideas and design that went into the new Tarmac.