Specialized Tarmac Disc Sport

As the most affordable carbon fibre Tarmac with disc brakes, there's a lot riding on the Tarmac Disc Sport being a good bike because it's likely that it will sell in much greater numbers than the stunningly good S-Works Tarmac I reviewed in 2017. Thankfully, although not as light and flighty as that bike, the Tarmac Disc Sport is really good, offering great handling and brisk performance. Perhaps the only wrinkle is that some brands will sell you an Ultegra groupset on a carbon frame for about the same money. That aside, you're getting probably one of the best carbon race frames currently available at this price, with great upgrade potential.

• Pros: Great handling, fast, fun, comfortable
• Cons: Weight, lower spec than some rivals

If the S-Works Tarmac is the GTI of the range, the Tarmac Disc Sport is the humble 1.0 litre. Same fundamental design but with fewer frills. On the road, that means a very impressive performance with similar handing – no surprise given the identical geometry.

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If you ride both bikes back-to-back you'll notice a difference, but most of that is down to the lower weight and the aero wheels of the S-Works bike. Tested in isolation and without the lucky opportunity to sample the S-Works, you certainly won't feel shortchanged. It is fast and highly capable with all the handling hallmarks of the more expensive bike.

On every ride I took the Tarmac Disc Sport on over my local Cotswolds roads, the quality and performance of the frame shone through. It gathers speed nicely and the hydraulic disc brakes scrub speed easily.

The frame and fork are stiff and responsive; it's as comfortable as you want a race bike to be, the handling making it easy to live with, being docile at slow speeds but sharp and focused when you're sailing along.

The steering instils confidence to sling the bike merrily through turns at any speed. There's no hint of nervousness or twitchiness, and I wasn't able to upset the controlled ride in any situation I put it in.

It has the handling you expect and want of a race bike for quickly changing direction, yet it's calm enough that I wouldn't hesitate to use it for a longer distance ride or sportive. The company's Roubaix might be the more natural choice for the sportive customer, but if you want a speedy and responsive ride then the Tarmac has a lot going for it. It's easy to live with if you want one bike that can throw its hand equally to racing and sportive duties.

The comfort of the latest generation race bikes has really improved, and despite wearing only 26mm wide tyres, the Tarmac is adept at dealing with poorly surfaced roads and isolating you from all but the biggest vibrations. The slight change to the seat tube and seatpost do mean a small loss of compliance compared with the S-Works model, but the difference is thankfully small enough that for the most part it doesn't negatively impact the quality of the ride.

There is space for up to 30mm tyres, too, so you could easily pop on some wider rubber if you wanted to up the comfort factor.

Frame

Visually, the Tarmac Disc Sport is almost identical to the range-topping S-Works, and indeed it shares a lot of key features such as the shape of the main tubes, the slightly aero down tube and the dropped seatstays, but there are some key differences.

Firstly, the difference you can't see is the carbon fibre. Instead of the FACT 12r of the S-Works, this frame is constructed from FACT 9r, essentially a lower grade of carbon fibre that keeps the cost down but does raise the weight. You're looking at about 950g for the frame, which is still pretty damn light.

Differences you can see include a straight seat tube with no aero cutout for the rear wheel and it's topped off with a round seatpost rather than the D-shaped seatpost of the S-Works. As well as that, the seat clamp is external (which is no bad thing as it's easier to access) and, joy of joys, there's a threaded bottom bracket. Specialized has been leaning towards threaded BBs on its lower-priced bikes for ease of maintenance, but is sticking to press-fit at the high end where performance is everything. For a bike that is more likely to be serviced at home than by a pro mechanic or bike shop, that's no bad thing.

Cables and hoses are still routed internally via a small port in the top of the down tube and inside the fork blade, providing a nice clean appearance to the bike.

The disc brakes are of the flat mount variety with a 160/140mm rotor combination, and 12mm thru-axles keep the hubs in place. Don't forget your multi-tool when going for a ride as the thru-axles are of the leverless variety.

The same Rider-First Engineered approach still applies, which is Specialized's name for size-specific frame design and construction to ensure every height rider has the optimised performance. There's also now the same geometry for men and women, with only the key touch points changing.

Build and equipment

Something Specialized has always done well is to nail the contact points. The Toupe Sport Body Geometry saddle is a thing of supreme comfort with generous padding and a shape that suited me perfectly. Specialized offers a wide range of saddles and your local Specialized dealer would be able to assist in choosing the right saddle for you; that's the sort of extra service you get compared to buying a bike over the internet.

Also comfortably shaped is the aluminium Shallow Drop handlebar. It has a short reach to the hoods and the drops aren't so low that you can never conceive using them. The S-Wrap Roubaix bar tape is lovely too, with a very cushy feel that enhances the quality of the ride. It's a funny thing, but cheap rubbish bar tape can really ruin the ride experience for me, especially when riding without gloves.

The carbon fibre seatpost shares the same saddle clamp and slight bend that is designed to improve saddle deflection over bumpy roads, but it's a round shape rather than the D-shape of the range-topping S-Works. It's tricky to asses how much difference it makes in comfort terms without removing the other variables between the two different bikes.

Shimano's latest 105 groupset, here in 50/34 and 11-30t configuration, is an excellent setup. At this price, it really has no rival, with features and technology trickled down from Dura-Ace. It's mechanical only, but the gear shifts are feathery light and it never missed a gear change once. The range is ample for dealing with any hilly sportive but you've got enough high-end for dispatching fast roads.

The hydraulic disc brakes, with 160/140mm rotors, provide pin-sharp stopping with plenty of modulation for controlling the power. The levers and hoods are ergonomic and whether riding in the hoods or drops, controlling the disc brake power is a doddle. There's never a risk of locking a wheel in the wet, and there's no annoying rubbing even when honking out of the saddle up a grunty climb or sprinting for the town sign finish line.

The DT R470 Disc wheels are a familiar sight on lower-priced Specialized bikes and every time I've ridden them I've had no issues. They aren't the flashiest, lightest or most aero wheels, but they are dependable with the sealed cartridge bearing hubs being reliable and the 24 spokes staying well tensioned despite a hammering.

The shallow aluminium rims are tubeless-ready and going tubeless is as easy as it gets, though first you'll need to buy some new tyres, tubeless valves and sealant because the Turbo Pro tyres aren't tubeless. They do offer low rolling resistance and good grip in the dry and wet, and the BlackBelt puncture protection duly provides decent resistance against flats.

Rivals

The Tarmac has always been a very comprehensively capable bike, and the changes made to this sixth generation version have made it even better. The all-new frame offers improved performance and ride quality over its predecessor, which goes some way to offset the fact that the Tarmac Disc Sport just can't compete with some rivals when it comes to value for money.

> Buyer's Guide: 10 of the best Shimano Ultegra-equipped road bikes

The Shimano 105 groupset is excellent, but Canyon will sell you an Ultimate CF SL Disc 8.0 with an Ultegra groupset for £2,349, with a claimed weight of 7.6kg.

Verdict

Race-ready performance with great handling and decent comfort, the Tarmac Disc Sport shines everywhere bar value