Specialized Roubaix SL8 Sport 105
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Specialized Roubaix SL8 Sport 105

Endurance machine with comfort-boosting front suspension

Our rating

4.5

3800.00
3500.00
3000.00
5400.00

Andy Lloyd / Our Media

Published: September 20, 2024 at 4:00 pm

Our review
Game-changing Future Shock suspension not only boosts comfort, it also makes you faster, especially over poor surfaces

Pros:

Shimano 105; Future Shock suspension; supreme comfort; high-quality tyres; fast, all-surface ride capability

Cons:

Average wheels

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The Specialized Roubaix SL8 Sport is the latest incarnation of Specialized’s long-standing and successful Roubaix endurance bike.

The present range features Future Shock suspension hidden under the stem, a compact frame, a carbon seatpost and dropped seatstays for comfort, as well as some aerodynamic benefits.

Specialized has also boosted tyre clearance to 40mm, putting it firmly into all-road and light gravel riding territory.

In fact, Specialized’s overworked marketing team claims the Roubaix SL8 is ‘lighter, faster and smoother’ than any road bike ever made.

The Roubaix SL8 Sport’s ride is certainly impressively smooth over surfaces ranging from rough country lanes to rutted grit and gravel, without sacrificing speed.

Specialized Roubaix SL8 Sport 105 frame details

Specialized Roubaix SL8 Sport 105 road bike
The seatstays are dropped for optimum comfort. Andy Lloyd / Our Media

There aren’t too many surprises when it comes to the Roubaix’s frame and fork – a full-carbon pairing made in Taiwan.

Fans of threaded bottom brackets will be pleased to see that standard here, and there are a few features that demonstrate the bike's all-road or even gravel-adjacent riding ambitions.

The Roubaix’s tyre clearance has gone up significantly compared to the previous generation, from 33mm to 40mm, which offers a massive range of road tyres from which you can choose.

Specialized says it has shaved 50g from the frame, so it now tips the scales at only 825g (claimed, in a size 56cm).

For an all-roader with light gravel-riding ambitions, it remains impressive, even if the overall 9kg weight isn’t that light.

While neither the frame nor fork have fittings for racks (which some, understandably, will see as an oversight), you get more than the usual number of bosses on the frame.

In addition to the usual inner-triangle bottle bosses, there’s also a pair underneath the down tube, while the top tube gets ‘bento box’ mounts.

Specialized Roubaix SL8 Sport 105 road bike
The riser bar adds another 25mm to the height at the front. Andy Lloyd / Our Media

But it’s the bike’s comfort that Specialized emphasises, and just above the head tube sits the discreet Future Shock unit. Here, it’s the basic ‘3.1’ version, with an undamped spring providing the 20mm of travel.

The frame leaves a fair amount of the seatpost exposed to further boost comfort, but what isn’t so evident is the Roubaix’s ‘Dropped Clamp’. This in fact clamps the seatpost 65mm down into the seat tube, which enables the post to flex further still. Specialized refers to this design as ‘AfterShock technology’.

Less important to me, Specialized’s designers have also made the frame and fork more aerodynamic by changing the shape of the fork and dropping the seatstays lower, which is claimed to help hide them from the wind.

My colleague Ashley Quinlan rated the Roubaix’s speed highly when he rode the S-Works Roubaix SL8 at launch.

Specialized Roubaix SL8 Sport 105 geometry

Three quarted pack shot of the Specialized Roubaix SL8 Sport 105 road bike
Geometry is a touch more relaxed than its rivals. Andy Lloyd / Our Media

The Roubaix’s endurance geometry is pretty similar to that of the Basso Venta R and Merida Scultura Endurance 4000 I've also tested – just a little bit more relaxed than either.

It has the longest wheelbase of the test trio, at 4mm longer than the Merida in an equivalent size 54cm, although at 1,005mm it’s 27mm longer than Specialized’s Tarmac race bike.

Interestingly, at 122mm, the Roubaix has a much shorter head tube on paper, not only than the other two bikes it’s up against, but also the Tarmac’s 137mm.

However, these disparities are eased out by the space the Future Shock takes up in the stem and the height added by the rise of the Roubaix’s handlebar.

As a result, the Roubaix has the highest stack figure of the three test machines, although the stack is only 5.5mm greater than the Basso and 1mm more than the Merida.

The 72.3-degree head angle doesn’t lead me to expect lazy handling.


 44 49 52 54 56 58 61 64
Seat tube angle (degrees) 75 74 74 74 73.5 73.5 73.5 73
Head tube angle (degrees) 69.3 70.8 71.5 72.3 73 73 73.5 73.5
Chainstay (mm) 418 418 418 420 420 423 423 423
Seat tube (mm) 365 410 446 465 485 505 545 581
Top tube (mm) 503 523 534 550 569 584 600 618
Head tube (mm) 90 90 105 122 140 168 202 222
Fork offset (mm) 52 52 52 47 47 47 47 47
Trail (mm) 76 66 62 61 57 57 54 54
Bottom bracket drop (mm) 80 80 80 78 78 78 78 78
Bottom bracket height (mm) 269 269 269 270 270 271 271 271
Wheelbase (mm) 994 992 998 1005 1012 1031 1042 1054
Standover (mm) 686 719 747 766 787 809 847 865
Stack (mm) 543 549 556 585 605 630 665 685
Reach (mm) 353 363 370 381 389 397 403 409

Specialized Roubaix SL8 Sport 105 specification

Specialized Roubaix SL8 Sport 105 road bike
The SL8 Sport is equipped with full 12-speed Shimano 105 R7100. Andy Lloyd / Our Media

As the name suggests, the Roubaix SL8 Sport 105 gets a full raft of 12-speed hydraulic Shimano 105 R7100 components.

The Roubaix gets the familiar 50/34 compact chainset but goes even further than the Basso and Merida in speccing the widest 11-36t 105-level cassette. Every little helps when things get steep, so this gets a thumbs up from me, and should appeal to those who want to make climbs as easy as possible.

The result is a sub 1:1 ratio bottom gear, and a gear range of around 26-124in, which should cover most of us for most situations.

And with 12 ratios there are still no huge gaps between gears, with one-tooth jumps for the first five gears and four-tooth jumps only for the last three shifts. Shifting was smooth and accurate across the range.

Braking is powerful and controlled, with great modulation – and requiring very little effort.

Specialized Roubaix SL8 Sport 105 road bike
Braking performance is excellent. Andy Lloyd / Our Media

But as good as Shimano 105 is, it's not the highlight of the Roubaix spec – that title belongs to the Future Shock suspension stem.

It’s not obvious when you first look at the bike, because unlike mountain bike suspension or the RockShox fork that shocked Paris-Roubaix in the early 1990s, it’s hidden in the stem.

The system offers 20mm of “smooth, stiction-free travel between the stem and head tube” according to Specialized. It’s not wrong – it really works.

The suspension consists of a spring that absorbs impacts and up to five preload washers, which influence the compression rate. You can choose from firm, medium and soft springs (which are all supplied).

For those worried about wear, Specialized says the latest incarnation is also the toughest and most resistant to the elements, thanks to the use of a thicker boot and a greater number of seals.

This front suspension is paired with Specialized’s Pavé carbon seatpost, named after Paris-Roubaix's famous cobbles. The dropped clamp is designed to ensure there’s a lot of exposed seatpost for additional compliance.

Specialized Roubaix SL8 Sport 105 road bike
A Specialized Power saddle sits atop the carbon Pavé seatpost. Andy Lloyd / Our Media

I was a bit surprised that the Pavé has a D-profile, resembling a skinnier version of Giant’s D-Fuse post. Specialized describes it as the first seatpost that’s “[both] compliant and aerodynamic”.

The Pavé post is topped by Specialized’s short-length Power saddle, which I got on with very well (albeit, of course, saddle fit is subjective).

The comfort theme is finished off with Supacaz’s excellent Super Sticky Kush bar tape wrapped around a bar that has slightly flattened, wing-profile tops – said to be for additional comfort, rather than any potential aero benefit.

The riser bar adds another 25mm to the height at the front, which may not appeal to all, but helps to relax the riding position a little (and complement the components immediately beneath it).

Specialized Roubaix SL8 Sport 105 road bike
The Future Shock is the highlight of a very impressive package. Andy Lloyd / Our Media

The wheels are the same as on the Roubaix SL8 Comp that Warren reviewed.

He found the wheelset, pairing DT Swiss GT540 alloy rims and Specialized hubs, solid and unflashy, but he felt what is essentially a £200 wheelset was out of place on a five-grand bike.

On this cheaper bike, they’re a sounder choice, but still ripe for a later upgrade.

The tyres are 32mm S-Works Mondo 2BRs, which are tubeless-compatible and impressive to see at this price point, where other brands might spec middling tyres.

Specialized Roubaix SL8 Sport ride impressions

Male cyclist in blue top riding the Specialized Roubaix SL8 Sport 105 road bike
It's a very able climber. Andy Lloyd / Our Media

The Roubaix’s exceptional comfort comes with an added bonus: in spite of its 9kg weight, it makes it one of the fastest bikes I’ve ridden.

I value comfort over all-out performance, with my racing days rapidly disappearing in the rear-view mirror, but I still put the hammer down occasionally. The Roubaix excelled when I did.

The extra comfort means you can put in the same amount of effort for longer, without feeling fatigue – without your fingers, hands and wrists starting to ache.

I started the test on the back of having a tendon issue in my right wrist that necessitated wearing a brace, and my wrist was noticeably more comfortable after riding the Roubaix than on other bikes.

If you happen to suffer from hand or wrist-pain issues, this alone could make this generation of Roubaix worth a test ride.

While the seatpost isn’t as cushioning as the supremely effective front suspension, the rear end is still relatively comfortable.

This is enhanced by the 32mm tyres, which, like those on the Merida, balloon out to over 34mm when inflated – that’s a lot of air between you and the tarmac, grit, gravel or towpath, while you can easily opt for lower pressures compared to narrower rubber.

Male cyclist in blue top riding the Specialized Roubaix SL8 Sport 105 road bike
The 32mm tyres enhance the sense of comfort. Andy Lloyd / Our Media

The smoothness delivered by the bike also means you’re quicker over rougher surfaces and bumps.

Specialized says impacts at the bar and saddle are reduced by 53 per cent compared to “the nearest competition”. I can’t corroborate the exact figure, even with 30 years of testing bikes under my belt, but it’s noticeable how exceedingly smooth the ride quality is.

Only hazards such as hard-edged potholes challenge the capacity of the Future Shock 3.1 suspension.

Crucially, this isn’t achieved at the expense of the bike's overall handling. It climbs well, descends niftily and the only time I became aware of the Future Shock suspension negatively impacting handling was when I was trying to challenge it with a deliberately ragged uphill full-on sprint. Here, the bike feels as though it loses a little front-end stiffness.

Male cyclist in blue top riding the Specialized Roubaix SL8 Sport 105 road bike
The handling is superb on tarmac and light gravel. Andy Lloyd / Our Media

However, over rough country roads, grit, light gravel and towpaths, the handling is as good as it gets.

The Mondo tyres proved great – they're excellent on tarmac, and grippy and supple over all sorts of unsurfaced routes. The rims and tyres are tubeless-ready, although Specialized supplies the bike with inner tubes.

But put on some dedicated gravel tyres and I’d happily tackle Salisbury Plain’s military tracks and much more gnarly singletrack surfaces in the name of fun.

Specialized Roubaix SL8 Sport bottom line

Male cyclist in blue top riding the Specialized Roubaix SL8 Sport 105 road bike
The SL8 is fast, comfortable and controlled – it's a top-tier road bike. Andy Lloyd / Our Media

I’ve ridden numerous Specialized Roubaix bikes in the past, but this is my first experience of one fitted with Specialized’s Future Shock suspension – and it’s great.

As a rider who favours comfort over stiff performance these days, the front-end compliance is the best out there, and it does this without compromising control.

The unexpected spin-off is that it makes the SL8 Sport a very fast bike, its ability to offer a smoother ride noticeably reducing cumulative fatigue. Shimano 105 is practically faultless for a mechanical groupset, and the 40mm tyre clearance and extra frame fittings make this a very versatile ride too.

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Product

Brand specialized
Price 5400.00 AUD,3800.00 EUR,3000.00 GBP,3500.00 USD
Weight 9.0000, KILOGRAM (54cm) -

Features

Fork Future Shock 3.1 w/ Smooth Boot, FACT Carbon
br_stem Future Stem Comp
br_chain Shimano 105, 12-Speed
br_frame FACT 10R, Rider First Engineered
Tyres S-Works Mondo 2BR, 700x32c
br_brakes Shimano 105 Hydraulic Disc
br_cranks Shimano 105, 50/34
br_saddle Body Geometry Power Sport, steel rails
br_wheels DT Swiss G540 rims, Specialized hubs, DT Swiss brass nipples
br_shifter Shimano 105 R7120, Hydraulic Disc
br_cassette Shimano 105, 12-speed, 11-36
br_seatpost S-Works Pavé carbon
br_gripsTape Supacaz Super Sticky Kush
br_handlebar Specialized Hover Comp, alloy
br_bottomBracket Shimano BSA
br_availableSizes 44, 49, 52, 54, 56, 58, 61, 64cm
br_rearDerailleur Shimano 105
br_frontDerailleur Shimano 105