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Specialized Tarmac Disc Comp review

The lightest and fastest Tarmac ever, and one of our Performance Bike of the Year 2020 contenders

Our rating 
4.0 out of 5 star rating 4.0
GBP £2,899.00 RRP | USD $3,500.00 | EUR €3,399.00 | AUD $4,500.00
Specialized Tarmac Disc Comp

Our review

Sharp, swift, superb speedster from Specialized
Pros: Quick but balanced handling; a fast machine
Cons: Modest wheelset for the price; front end’s harder than the rear
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The SL6 frame design on this Specialized Tarmac Disc Comp has been with us for over a year now and there’s a clear theme across the range: dropped rearstays, which start lower down the seat tube than traditional versions, and aerodynamic tubing meets a straight fork that flows into a sculpted and deep, yet slender, head tube.

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The Tarmac Comp’s Fact 9r frame comprises a more modest carbon-fibre lay-up than the S-Works’ Fact 12r, although it still weighs less than a kilo; throw in a 300g fork for a decent overall weight of 8.33kg.

However, the most significant design difference is the seat tube. On the S-Works, it’s a D-shaped tube and post (as seen on the Focus Izalco Max Disc 8.8) with rear-wheel cutaway, whereas the Tarmac Comp’s a standard round tube with a 27.2mm carbon post.

You might lose a hint of aerodynamics, although it gives you plenty of options to chop and change.

Bike of the Year 2020

The Specialized Tarmac Disc Comp is part of our annual Bike of the Year test.

Head to our Bike of the Year hub for the full list of winners, categories and shortlisted bikes, as well as the latest reviews – or read our behind-the-scenes feature on how we tested Bike of the Year 2020.

Specialized Tarmac Disc Comp geometry

Specialized Tarmac Disc Comp
Reflecting the trend toward larger tyres, the bottom-bracket height has been dropped by 3mm.
David Caudery / Immediate Media

Geometry broadly mimics previous models, though the bottom-bracket height is dropped by 3mm, reflecting the trend toward larger tyres.

The wheelbase stretches to 1,002mm to allow for discs. Throw in parallel 73.5-degree angles, a low 591mm stack (on my 58cm) and a long 402mm reach and you have a highly responsive bike that revels in being ridden hard and fast.

That stiff chassis maximises speed and lifts cornering confidence, while snappy steering means you can avoid a pothole with telepathic speed.

  • Seat angle: 73.5 degrees
  • Head angle: 73.5 degrees
  • Chainstay: 41cm
  • Seat tube: 54cm
  • Top tube: 58.1cm
  • Head tube: 19cm
  • Fork offset: 4.4cm
  • Trail: 5.5cm
  • Bottom bracket drop: 7.2cm
  • Bottom bracket height: 26.8cm
  • Wheelbase: 1,005mm
  • Stack: 59.1cm
  • Reach: 40.2cm

Specialized Tarmac Disc Comp kit and ride impressions

Specialized Tarmac Disc Comp
Shimano’s Ultegra groupset throughout.
David Caudery / Immediate Media

It’s Shimano Ultegra mechanical throughout, and the gearing reflects the Tarmac’s racy intentions with a 52/36 chainset and 11-30 cassette.

A 52/11 combo’s sufficient for power-laden speedsters; a bottom gear of 36/30 is low enough for the most challenging of climbs.

Specialized Tarmac Disc Comp
Neat internal cable routing.
David Caudery / Immediate Media

Upfront it’s all Specialized with a 3D-forged stem clamped to an alloy, compact drop bar. The bar is a great shape, but it’s stiff. Throw in the 26mm wide tyres and you have a front end that can become choppy on rougher roads.

By contrast, the rear end’s near perfect. A quality carbon 27.2mm seatpost with layback offers give, and it’s topped with the most comfortable saddle on test: Specialized’s Body Geometry Power. This is the original ‘short’ saddle that kickstarted a trend.
Specialized Tarmac Disc Comp
Specialized’s Body Geometry Power Comp short saddle.
David Caudery / Immediate Media

The Tarmac rolls on Specialized’s Gripton-compound Turbo tyres with added black-belt protection. One I’d recommend for winter rides.

They’re wrapped around DT Swiss’s R470DB rims on Axis hubs. DT describes that rim as a jack-of-all-trades, and you can appreciate why because the 20mm internal width can be used with wider tyres; the Tarmac can easily handle 28mm or 30mm tyres.

Specialized Tarmac Disc Comp
Specialized’s Turbo Pro Gripton Blackbelt 700 x 26c tyres were fitted but the bike can take up to 30mm.
David Caudery / Immediate Media

The rim is 32mm deep and compatible with tubeless tyres, although you’ll need to add valves and tape.

The Axis hubs are a Specialized design with DT Swiss internals. They’re perfectly serviceable wheels, but we’ve seen better value at this price.

Specialized Tarmac Disc Comp overall

Specialized’s latest Tarmac Comp delivers a highly responsive and fast journey aboard its game-changing Body Power saddle. A hint of roughness didn’t diminish a fine ride.

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If you want a classy, race-orientated bike the Tarmac Comp could be the bike for you.

With thanks to…

BikeRadar would like to thank 100%, Q36.5, Lazer, Garmin and Facom for their support during our Bike of the Year test.

Product Specifications


Price br_price, 5, 3, Price, AUD $4500.00EUR €3399.00GBP £2899.00USD $3500.00
Weight br_weight, 5, 6, Weight, 8.32kg (58cm), Array, kg
Brand br_brand, 5, 10, Brand, Specialized


Available sizes br_availableSizes, 11, 0, Available sizes, 44, 49, 52, 54, 56, 58, 61cm
Bottom bracket br_bottomBracket, 11, 0, Bottom bracket, Shimano threaded
Brakes br_brakes, 11, 0, Brakes, Shimano Ultegra hydraulic 160/140 Ice Tech rotors
Cassette br_cassette, 11, 0, Cassette, Shimano Ultegra 11-30
Chain br_chain, 11, 0, Chain, Shimano Ultegra
Cranks br_cranks, 11, 0, Cranks, Shimano Ultegra 52/36
Fork br_fork, 11, 0, Fork, Fact 9r carbon
Frame br_frame, 11, 0, Frame, Fact 9r carbon
Front derailleur br_frontDerailleur, 11, 0, Front derailleur, Shimano Ultegra braze-on
Handlebar br_handlebar, 11, 0, Handlebar, Specialized Shallow Drop, 6061
Rear derailleur br_rearDerailleur, 11, 0, Rear derailleur, Shimano Ultegra
Saddle br_saddle, 11, 0, Saddle, Specialized Power Comp
Seatpost br_seatpost, 11, 0, Seatpost, S-Works FACT carbon
Shifter br_shifter, 11, 0, Shifter, Shimano Ultegra
Stem br_stem, 11, 0, Stem, Specialized, 3D-forged alloy
Tyres br_tyres, 11, 0, Tyres, Specialized Turbo Pro Gripton Blackbelt 700 x 26c
Wheels br_wheels, 11, 0, Wheels, DT Swiss R470DB