As the new official bike of professional UCI teams like BORA-Hansgrohe and Deceuninck-Quick-Step, you’re going to see the Specialized S-Works Tarmac SL6 Disc in countless races. According to rumours from the pro peloton the bike is fast as hell. But does the new Tarmac have the winning DNA it needs to stand up to its competitors?

This bike is part of a previous group test. Here you’ll find the latest GRAN FONDO race bike group test.

Specialized S-Works Tarmac Disc SL6 Disc | 6.58 kg | € 10.799

There’s no doubt that with such a superb design even the fiercest Specialized critics will have a hard time finding a valid argument against the new S-Works Tarmac SL6 Disc. With its organic lines, the frame looks timeless and innovative at the same time. The sloped top tube allows for an extended seat post and gives every rider the desirable pro-look. Specialized relies on a proven Shimano Dura-Ace Di2 R9170 groupset and 160 mm/140 mm rotors, front and rear respectively. The spec of the Tarmac also includes 50 mm-deep Roval CLX carbon wheels with CeramicSpeed bearings and 26 mm Specialized Turbo Cotton tires. This combination increases the actual tire width to 28 mm.

Without pedals, the Tarmac SL6 Disc weighs just 6.58 kg. That’s illegal – don’t let the UCI know!

The brand-own D-shaped carbon seat post comes with a 20 mm setback. The cockpit of the Tarmac combines a 100 mm S-Works SL aluminium stem with 420 mm S-Works carbon handlebars and to be honest, we were almost surprised with such a conventional choice. The only flaw in our test bike is the Di2 cable-mess under the stem. Specialized is the only manufacturer in our group test to deliver their bike with a dual-sided power meter from the factory, yet still managed to keep the weight down to a staggering 6.58 kg in size 56, making it the lightest bike in our test. After a price increase at the beginning of the year, the SL6 now costs € 10,799.

The Specialized S-Works Tarmac Disc SL6 Disc in detail

Drivetrain Shimano Dura-Ace Di2 R9170 2×11
Gearing 52/36T und 11-30T
Brakes Shimano Dura-Ace BR-9170 160/140 mm
Seatpost S-Works FACT Carbon Tarmac 20 mm Setback
Stem S-Works SL 100 mm
Handlebars S-Works Shallow Bend Carbon 420 mm
Wheels Roval CLX 50 Disc w/ CeramicSpeed
TiresSpecialized Turbo Cotton 25C

Addiction to friction
Specialized relies on smooth-running CeramicSpeed components for the bottom bracket and wheel bearings.
Extreme measures
The S-Works Tarmac SL6 Disc comes with a dual-sided Specialized power meter from the factory.
A perfect balance
The Tarmac runs a 160 mm rotor in the front and 140 mm in the rear. This combination strikes an optimal balance between braking performance and weight.
Obstructed views
The cable mess right in front of the Specialized logo on the head tube is the only aesthetic eyesore.

The geometry of the Specialized S-Works Tarmac Disc SL6 Disc

Size 49 52 54 56 58 61
Seat tube 431 mm 462 mm 481 mm 501 mm 522 mm 553 mm
Top tube 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 1,005 mm 1,012 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

The Specialized S-Works Tarmac Disc SL6 Disc in test

The harmonious interplay between low weight, smooth-running bearings and a stiff bottom bracket allows for quick acceleration. Not only does the Tarmac fling you up to speed from a standstill, but it maintains the same lively character on steep climbs. These qualities make it the undisputed climbing-king in our test!

Tuning tip Heat shrink tubing for the cable
Helmet POC Ventral Air SPIN | Glasses Oakley Wind Jacket | Jersey WEOUTDOOR NEWZEBRA | GREY’S SERIE Bibs WEOUTDOOR TATTOO BIBS | Socks Rapha Pro Team Socks long | Shoes Shimano S-PHYRE RC9

At the same time, the lower inertia and overall mass make it less efficient on the flats. In other words – heavier bikes have more momentum, and so can carry their speed better in some situations. With its superb handling, the Specialized dazzled us in every single turn!

Once more Specialized’s design-team strikes the perfect balance between agility and smoothness – which means we weren’t missing either. The Tarmac feels consistently direct without overwhelming you with quick direction changes and always rides smoothly without feeling boring. It was damn hard to push the Tarmac beyond its comfort zone! Accordingly, the Specialized inspires huge amounts of confidence. Thanks to the carbon layup, the frameset provides an unexpectedly high level of compliance without feeling spongy. The cotton-carcass tires, carbon handlebars and seat post enhance the high overall comfort even further. On this bike, the clever interaction of components provides an outstanding and well-balanced level of comfort. Specialized doesn’t rely on any specific comfort systems.


Whether you consider yourself a weight-weeny, weekend-warrior or pro-racer you’ll have a whale of a time on the new Tarmac – and feel safe while doing so! The Tarmac strikes an optimal balance between speed and weight while inspiring a great deal of confidence – we’re impressed in every respect. The Specialized S-Works Tarmac SL6 Disc is the best race-bike of the year – a clear and well-deserved best in test!


  • Perfect compromise between speed, comfort and safety
  • Perfectly balanced handling
  • Low weight at the limit of legality (don’t tell the UCI-people!)
  • Integrated dual-sided power meter


  • Di2 cable mess

Fore more info head to:

This bike is part of a previous group test. Here you’ll find the latest GRAN FONDO race bike group test.

All bikes in test: Argonaut Road Bike | Basso Diamante SV 2019 | Bianchi Oltre XR4 Disc | BMC Timemachine Road 01 TWO | Canyon Ultimate CF SLX Disc 9.0 | Cervélo S5 | EXEPT Allroad Classic | FOCUS IZALCO MAX 9.8 | MERIDA REACTO DISC TEAM-E | Trek Madone SLR 9 Disc

This article is from GRAN FONDO issue #011

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Words: Photos: Valentin Rühl