Specialized Roubaix SL8 Expert review

The Specialized Roubaix SL8 represents the third incarnation of the Future Shock-equipped endurance road bike design.

There’s aerodynamic influence from the Tarmac SL8, yet the focus is on making the Roubaix more of an all-road proposition rather than a pure endurance bike.

In testing, I’ve found it is extremely capable and versatile, but on the road this can result in a slightly unbalanced feel. That said, love or loathe suspension tech in road bikes, the Roubaix Expert is a very smooth operator.

Specialized Roubaix SL8 Expert frame details

The Specialized Roubaix SL8 frame is lighter than the previous generation by a few grams (a claimed 50g on the S-Works level frame).

This is quite an achievement when you consider the amount of aerodynamic restyling, plus the increased tyre clearance (up to 40mm) and additional mounts.

Those mounts include a third set of bottle bosses underneath the down tube and bento box mounts on the top tube.

This means the Roubaix SL8 is something of an all-road and light gravel bike, in addition to its road-going roots. It's similar in many respects to the Cervélo Caledonia, Cannondale Synapse, Vitus Venon Evo and Merida Scultura Endurance.

Mudguard mounts are present and correct, which is something notably omitted on the Canyon Endurace CFR.

Somewhat at odds with this all-road angle are the claimed improvements in aerodynamics.

Specialized tells us a rider putting out three watts per kg over a 100km ride would end up finishing 11 seconds faster than before (or be 17 seconds quicker covering 100 miles).

This is while Specialized hasn’t been able to do the trick of hiding the brake hoses, given the Future Shock system prevents running them through the head tube. Here, it looks slightly old-school with the front brake hose entering at the fork crown.

Nevertheless, this is the most race-oriented silhouette a Future Shock-equipped Roubaix has ever had.

Future Shock 3.0 and rear compliance

Up-front, the Specialized Roubaix SL8 Expert features the mid-level Future Shock 3.2 unit, ensconced in the head tube.

This version has a fixed fluid damper. The adjustable damper in the Future Shock 3.3 model is found on the £12,000 / $14,000 / €14,000 / AU$19,900 S-Works or £8,000 / $8,500 / €9,000 / AU$11,900 Pro models.

Three springs are supplied. The middle-tension unit is pre-installed and I found this offered a happy medium of compliance through the front.

At the rear, a new aero seatpost is claimed to deliver up to 18mm of flex, although this is fortified by large tyres and the Specialized Power saddle.

Specialized Roubaix SL8 Expert geometry

Specialized hasn’t messed with the Roubaix’s ride position and steering geometry, and that’s a good thing.

The tall stack of 630mm and 397mm reach on my 58cm test bike are combined with a race-bike steep 73-degree head angle and a trail of 57mm. This brings plenty of sharpness to the steering.

The 73.5-degree seat angle is all about opening up the hip angle to get your power through the pedals.

On the road, the Roubaix feels rapid, without putting you into a pro-rider tuck in the process.

With the frame and fork now designed to accommodate 40mm-wide tyres, the front centre of the bike has elongated by 10mm and the wheelbase of 1,031mm (in a size 58cm) is up by 20mm.

Specialized Roubaix SL8 Expert build and specification

For £6,000 / $6,500 / €6,500 / AU$9,400, the Expert’s build is decent, though you will find better value elsewhere.

For example, the Giant Defy Advanced Pro 0 features Shimano Ultegra Di2 R8100 (a rival to Force AXS rather than Rival on the Roubaix), for the same price as the Roubaix Expert.

That said, SRAM Rival AXS offers near-identical performance to Force – it just carries a few extra grams in weight.

The shifting is accurate and smooth, and the braking feel and power are spot on too.

Specialized has also included a left-sided Quarq power meter.

Up-front, the alloy stem holds Specialized’s Hover bar, which has great ergonomics.

It has a mid-compact drop and reach which, thanks to the rise on the bar, you’ll spend far more time in than most of its competition.

The bar is an alloy version, which feels as though you're being short-changed considering the Defy Advanced Pro 0 has a carbon bar.

However, in reality, it has zero detrimental effect on comfort, thanks to the double-hit of the Future Shock system, plus the supple, soft and sticky Supacaz Kush bar tape.

The Expert runs on a Roval Terra C wheelset. This is the entry model in the carbon Terra range, though at £1,150 (aftermarket) it’s hardly a ‘budget’ option.

It weighs in at a claimed 1,610g, with a 32mm-deep, 25mm-wide (internal) rim shape.

It uses 24 DT Swiss Competition spokes, laced to DT Swiss’ newest version of its 370 hubs, with an 18-tooth Star Ratchet freehub giving a 20-degree engagement.

The wheels are tubeless-ready, as are the 700x32c Mondo tyres.

The bike doesn’t come set up tubeless, although a Specialized dealer may consider setting them up for you.

The tyres are compliant and grip well in the wet, but don’t have much in the way of zip – I think losing the inner tubes would have a positive effect on the overall performance.

Specialized Roubaix SL8 Expert ride impressions

The Roubaix is a quick bike, and the steering swiftness adds plenty of fun factor too.

The front end’s constantly active feel makes it stand out from the crowd, and the bike’s ability to cope with road bumps, scars and small potholes makes progress swift.

I found I didn’t need to slow down or ease off my effort when things started getting choppy.

The Roubaix is especially good on descents where corners have broken up on the surface, or washed-up detritus covers the road.

The large-volume tyres (which inflate to close to 34mm) grip well, while the Future Shock system serves to smooth the experience further.

The firmer rear end splits the bike into two halves, though.

On smoother roads, the rear feels markedly stiffer than the front, especially when you keep the medium spring in the Future Shock setup for the ride-smoothing benefits I’ve highlighted.

Riding over bigger bumps and rough roads, the rear gives some flexion, which takes the edge off vibrations. However, it still feels relatively stiff.

You could swap the spring on this Expert model for a firmer front-end experience to help match it, but it’s always going to be a compromise of preference.

Either way, the new Roubaix has lost some of the all-round smoothness of its post-2017 forebears.

I think this could also be alleviated if Specialized made different ‘weights’ of seatposts, as it does with the sleeve system on the Diverge STR gravel bike.

Specialized Roubaix SL8 Expert bottom line

The Roubaix is undoubtedly an impressive bike, with a ride that smothers rougher roads like little else.

If front-end smoothness is your thing, there’s little (if anything) to best it.

The ride feels a little unbalanced between front and rear, though. This reveals itself much more on smooth tarmac compared to rough, ragged roads.

While you can switch Future Shock springs to address the issue, that will remove some of the confidence-inspiring compliance.

Fundamentally, it’s a hugely versatile and comfortable bike with a great turn of pace, but if you get your kicks only from the road – or only gravel riding, for that matter – you may want to look at something more specialised (pun intended).