Finally with disc brakes! After presenting the fully-revised version of the Tarmac last year, Specialized is now introducing their new S-Works Tarmac Disc 2018. In this exclusive test we had the opportunity to ride the brand new disc-version and compare it against its rim brake antagonist.

If you missed the full review of the Specialized S-Works Tarmac 2018 rim-version, here is a little refresher: regardless of whether you’re pelting at 40 km/h on the flats, slowly climbing a mountain pass or blasting fast descents in your best aero-tuck, the Tarmac always feels precise and radiates an innate calmness, remaining reassuringly predictable and composed at all times but without feeling sluggish. Light-footed, stable, confidence-inspiring? Check!

The engineers at Specialized took almost a year to develop the new Tarmac Disc. Their top priority was maintaining the superb riding characteristics of the rim version. Did they succeed? We’ve found the answer with the hip-hoppers from Black Sheep.



Specialized Tarmac Disc models & prices
The Specialized Tarmac Disc will be available from March the 14th 2018 – but only in the S-Works version and at a price of € 9,999, which is exactly the same of the rim-version. Specialized is also releasing an S-Works Tarmac Disc frameset and planning to present even further models later this summer. The Women/Men models share the same frame with the only difference being the saddle, cockpit and crank lengths.



Specialized S-Works Tarmac Disc im Detail
Drivetrain Shimano Dura-Ace Di2
Brakes Shimano Dura-Ace Di2
Wheels Roval CLX 50 Disc Carbon
Tires Turbo Cotton 700 x 26
Weight 6.69 kg (56 cm)
Price € 9,999










Specialized Tarmac Disc geometry & sizing
The women’s and men’s models come respectively in six sizes (49,52,54,56,58,61). The disc version features the same geometry as the rim model, only the chainstays are 5mm longer on smaller frame sizes.
Size | 49 cm | 52 cm | 54 cm | 56 cm | 58 cm | 61 cm |
---|---|---|---|---|---|---|
Seat tube | 431 mm | 462 mm | 481 mm | 501 mm | 522 mm | 553 mm |
Top tube (horizontal) | 508 mm | 531 mm | 540 mm | 562 mm | 577 mm | 595 mm |
Head tube | 115 mm | 126 mm | 143 mm | 163 mm | 190 mm | 210 mm |
Head angle | 71.7° | 72.5° | 73.0° | 73.5° | 73.5° | 74.0° |
Seat angle | 75.5° | 74.0° | 74.0° | 73.5° | 73.5° | 73.0° |
Chainstay | 410 mm | 410 mm | 410 mm | 410 mm | 410 mm | 410 mm |
BB Drop | 74 mm | 74 mm | 72 mm | 72 mm | 72 mm | 72 mm |
Wheelbase | 973 mm | 975 mm | 978 mm | 990 mm | 1005 mm | 1012 mm |
Reach | 375 mm | 380 mm | 384 mm | 395 mm | 402 mm | 408 mm |
Stack | 514 mm | 527 mm | 544 mm | 565 mm | 591 mm | 612 mm |
Weight of the Specialized Tarmac Disc
The Specialized S-Works Tarmac Disc in our test weighs 6,69 kg while the S-Works Tarmac rim model with identical spec reads 6,38 kg on our scales. This means a difference of 310 grams between the two fully built bikes (both in a 56 cm size). The frame alone of the disc version is a just 67 g heavier than the rim model. With a weight of 800 g in a 56 size the Specialized Tarmac Disc has done itself proud!

Test Specialized Tarmac Disc vs. Rim
Let’s be honest, many disc race bikes often feel sluggish and cumbersome! A lot of bikes that were originally designed to work with rim brakes are only given basic facelifts and adapted with minimal modifications to be compatible with disc brakes. This can cause the bike to be less direct and more difficult to control than models with rim brakes. This is mainly due to the fact that disc brakes produce stronger forces and greater leverage than rim brakes.

But these problems are alien to the new Specialized Tarmac Disc! Most people wouldn’t even be able to tell the difference between the two bikes if riding blindfolded.

Only a direct comparison revealed some minimal differences: the front-end of the disc model feels a little more composed (but in no way sluggish!) and at the same time stiffer and more defined, which is imputable to the reinforced disc fork. The combination of a 160 mm disc at the front, a 140 mm rotor on the rear and the Shimano Dura-Ace Di2 disc brakes delivers incredibly well balanced braking power. And despite a light squeaking noise in wet conditions they still feel more consistent, intuitive and reliable than any rim brake in changing weather conditions. Even when decelerating hard the Tarmac Disc stays in control and shines with its precise, superb handling; this is somewhat surprising considering its slender shape. The bite point of disc brakes is way more appealing than the slightly delayed and sometimes more undefined touch of rim brakes due to stretching cables.



Many of us are still wondering whether road bikes can actually fully take advantage of the enormous power of disc brakes or if it’s all just a massive waste of technology. The answer is yes they can! Our tests in dry conditions revealed a difference in braking distance of around 10% between the disc and rim versions. Having said your braking skills also play a crucial role. Shifting your weight backwards while braking will increase the traction on the rear wheel and also allow you to squeeze the front brake harder without flying over the bars.

Conclusion Specialized S-Works Tarmac Disc
The new Tarmac Disc fills an important gap in Specialized’s portfolio, something we’ve been waiting to happen for a long time. So what’s the verdict then, discs or rim? Lower weight, easier handling and a classic look are good points in favour of rims. On the other hand the disc version of Specialized’s black racing-horse offers better control and more confidence. The price is the same and the performance is pretty much identical. We leave the final word to the legendary Black Sheep hip-hoppers: The choice is yours! If you can afford it take both – like our editor Manuel: Thug Life!

For more information head to specialized.com
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Words: Robin Schmitt Photos: Valentin Rühl, Robin Schmitt