Specialized Tarmac Disc Comp review

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.

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.

Specialized Tarmac Disc Comp geometry

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

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.

• Gear shifting explained

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.

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.

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.

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