Specialized S-Works Tarmac Disc review

The Specialized S-Works Tarmac Disc ranks as one of the best bikes we've ridden

Cycling Weekly Verdict

With the Specialized S-Works Tarmac Disc Specialized has made the best even better.

Reasons to buy
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    Amazing ride quality

  • +

    Stiffness hasn't compromised comfort and vice-versa

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    Excellent wheels

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Reasons to avoid
  • -


The Specialized S-Works Tarmac Disc SL 6 was already one of our favourite bikes, and then Specialized added disc brakes and took it to the next level. 

The SL 6 is the embodiment of what a high end bike should be; aggressive, fast, and grin inducing – that’s why it’s on our Editor’s Choice list.

Last year the sixth iteration of the Specialized S-Works Tarmac SL6 was debuted and quickly became a firm favourite of both ours and the pro-peloton's. This year, the brand released the Specialized S-Works Tarmac Disc, adding more powerful brakes into the mix and creating a truly spectacular bike.

The Specialized Tarmac has one of the most distinctive frame shapes of the last year. The dropped seatstay design has also proven to be one of the most compliant available and with the Tarmac that comfort is immediately noticeable, the frame ironing out all but the biggest bumps.

However, what's even more impressive is that Specialized hasn't sacrificed anything for that increased compliance. The added comfort doesn't remove any of the road feel that makes riding the bike so enjoyable and there's zero flex or squirming out on the road. It makes me think that the brand's Rider-First Engineering is spot on, with each frame size constructed in a bespoke way so that handling characteristics are the same across the entire size range.

Specialized S-Works Tarmac Disc

A beautiful bike

By re-evaluating the frame design Specialized has managed to slim down the tube profiles. The down tube is now smaller, as is the bottom bracket, without affecting stiffness in any way. Perhaps Specialized has put the nail in the coffin of the oversized bottom bracket, previously thought so important to frame stiffness.

Given the Specialized S-Works Tarmac Disc's whopping superbike price tag you'd expect a killer spec. Well, the bike is finished with Specialized's own-brand components, but nearly all of them earned a spot on our Editor's Choice list last year, making them brilliant products in their own right.

Most notably, it comes equipped with Specialized's new power cranks. Specialized made no attempts to hide the fact that the power meter used 4iiii's technology but that they had given it a different casing to better protect it from water. To date, it has worked very well, including through soaking wet weather.

Specialized S-Works Tarmac Disc

Dropped seatstays

The only fiddly bit about setting up the power cranks was taking the backing off the cases to remove the film from the battery. Once done, you pair the power cranks to the Specialized app, which is probably the slickest I've used.

The right side is a slave to the left, but you can unlink and forget both in the app. Fortunately, I never encountered a problem where this was necessary. Each side uses a coin cell battery, and so far each side is down to around 80 per cent after well over 500km of riding.

The Roval CLX 50 wheels are some of the best performing on the market and as a result one of our favourite wheelsets. They have a tangible stiffness out on the road, and when you stop pedalling they just hold their speed exceptionally well, increasing your average speed across the board.

Specialized S-Works Tarmac Disc

Some of our favourite tyres

Along with the superb frame, these wheels are probably the things that enhance the bike's performance the most.

Up front, the size 56cm bike has a 44cm bar, which does feel wide. It doesn't affect handling but a narrower bar would perhaps be more in line with the racing bike. It also has a shallow drop, which I actually prefer, because I don't have the flexibility of a pro rider.

The bike ships with a FACT carbon seatpost with a 20mm offset as standard. This could be a bit aggressive for some riders, including myself.

Specialized S-Works Tarmac Disc: the ride

Specialized S-Works Tarmac Disc

The Specialized S-Works Tarmac Disc comes with a power meter

This Specialized S-Works Tarmac Disc review was always going to be difficult to write. We loved the rim brake version but how does this model differ other than by its brakes?

Principally, there's a far more nuanced ride quality that comes from those more powerful brakes. It's perhaps easier to describe it as a rounding out of the bike; almost like the disc brakes complete the package.

For example, the simply superb Specialized Turbo Cottons give you the confidence that'll you'll always stay rubber side down. But by adding disc brakes to the bike, you now have complete confidence that you'll get round every single corner, and that you can shave off speed whenever you need to.

Similarly, the bike's aggressive geometry with its low head tube height and stable wheelbase had me flying round corners at speeds well above what I'd usually attempt. This bike pushed me at every opportunity to ride faster, but I felt confident doing so because I knew the disc brakes left me in total control.

Specialized S-Works Tarmac Disc

A definite highlight with the bike was riding the MagnifiCat 160km sportive. Even though my mates left me with 80km to go it didn't matter because I was riding this bike. It encouraged me to get on it hard to chase them down, pushing to ride at 35kph the whole time and flying down descents and attacking the climbs. It has made all solo rides not just bearable but a total joy.

The Specialized S-Works Tarmac Disc has the handling of a superbike and for me it's on a par with the Cervélo R5 Disc, probably the best handling bike I've ridden – until now. While the two bikes' handling might feel similar, the Specialized wins out in terms of all-day comfort.