Specialized S-Works Tarmac SL8 assessment: An wonderful bike let down by enforced specs

Specialized is without doubt one of the most well-known bike manufacturers on the planet, and for greater than a decade, the Tarmac has been the model’s flagship race bike. Despite a seven-year stint by which it shared the highest spot with the aero Venge, the Tarmac has all the time been the model’s finest highway bike. That grew to become much more definitive when in 2020, the model killed off the Venge, saying the Tarmac SL7 was the ‘one bike to rule all of them.’ 

The Tarmac SL8 is the following evolution of that bike, and since its launch in August 2023, I’ve ridden it in a number of guises. First in its S-Works model, with Dura-Ace Di2, Roval’s Rapide CLX II wheels and the one-piece Roval Rapide cockpit. Next got here the ‘Specialized’ body, full with Force AXS, a two-piece bar and stem, and the cheaper Roval Rapide CL wheels. And most lately I’ve been again aboard the S-Works body, once more with the Rapide CLX wheels and the Rapide cockpit, however with the newest Red AXS groupset. 

I’ve educated, raced, and even commuted to work on them to check their trip high quality, throughout vital areas like consolation, dealing with, agility and energy switch. I’ve additionally taken the bike to a wind tunnel alongside the perfect aero bikes for some laborious knowledge to again up my testing.  

Across the three builds, I’ve been capable of tease out what separates the Tarmac platform from opponents such because the Factor Ostro VAM and the Pinarello Dogma F, in addition to perceive the variations between the various specs. 

To lower an extended story brief, the bike is basically faultless. It’s light-weight, agile and actually enjoyable to trip, each on brief quick rides and on longer, slower extra endurance-focussed days. 

In our wind tunnel superbike check, the third of the aforementioned builds got here out quickest when examined with a rider so it is truthful to say it is aerodynamic too. 

It’s a hero product, so sadly for many of us, it has the worth tag to match. The S-Works Tarmac SL8 with Dura-Ace is at the moment priced at £12,000 / $14,000 / €14,000 / AU$19,900. 

That’s removed from low cost, however there are extra inexpensive choices within the vary, with full builds beginning at £6,000 / $6,500 / €6,500 / AU9,400. 

Design and aesthetics

At launch, the bike got here with a sequence of claims that even by Specialized’s personal requirements, had been extremely lofty. 

The model not solely referred to as it the “lightest on the WorldTour” with a body weight of 685g, however the “world’s quickest race bike” too. That’s alongside a reported enhance of 33% in stiffness to weight, and a 6% bump in compliance when in comparison with the outgoing Tarmac SL7.

Starting with weight, there is not any denying the Tarmac is certainly a light-weight bike.

When we took the S-Works Tarmac SL8 with Red AXS to the wind tunnel alongside 10 of its friends, we not solely examined the aero credentials (which I’ll get into shortly), we additionally weighed every bike and the Tarmac was the lightest of the bunch… simply. 

The Factor OSTRO VAM – with Shimano Dura-Ace Di2 – was third-lightest, tipping the scales at 7.23kg. The Pinarello Dogma F – additionally with Dura-Ace – was second at 7.20kg. The Tarmac snuck in at 7.18kg. Twenty grams is not a lot, and possibly should not have an effect on your resolution too strongly when you’re on a fence between Specialized and Pinarello, however a win is a win. 

One bike we did not have on that check is the Scott Addict RC, which launched extra lately in late 2024. That claims to be considerably lighter at 5.9kg for a full construct, with a 599g body. Given that Q36.5 Pro Cycling is not a WorldTour staff, Specialized’s declare of being ‘lightest on the WorldTour’ nearly holds true, though if weight actually issues for you, there are lighter bikes round. 

But weight is not the one issue, and anybody trying to purchase a race bike of this ilk might be extra eager about aerodynamics. Specialized says the bike will save 16.6 seconds over a 40km time trial when in comparison with the SL7, and in a few comically particular examples, 20 seconds over the Col du Tourmalet or 128 seconds over the 294km course of Milan-San Remo. 

Specialized says it focussed on “aero the place it really issues,” opting as a substitute to save lots of weight “the place aerodynamics issues much less or by no means.” In easy phrases, meaning it focussed extra on aerodynamics on the entrance of the bike – the place sculpting the wind makes extra of a distinction – and on lowering weight on the rear of the bike.

The results of that was the introduction of the ‘velocity sniffer’ (their phrases, not mine) nostril cone, in addition to the inclusion of the Roval Rapide one-piece cockpit on all S-Works fashions. 

Importantly, greater than half of the aero distinction between the SL7 and the SL8 got here by way of the Roval Rapide cockpit, and when you match an out-front bike laptop, you lose a few of that efficiency. 

At the rear, Specialized says that the turbulent air of a rider’s legs signifies that deep airfoil seat tubes present vanishingly small aero features, so as a substitute used this space to shed weight and add compliance. 

It thinned the seat tube, in flip making the SL8 seatpost inside so slender {that a} Di2 battery would not match inside, as a substitute needing to be mounted to a clip beneath. 

It additionally made the seat tube roughly 10% shallower, in flip growing its flex, including extra compliance and luxury. I can not say I’m capable of really feel that particularly, however the brand new Tarmac total is actually a extra snug bike to trip than the SL7.

The cheaper non-S-Works fashions use the identical body silhouette, including round 100g in weight by the much less premium Fact 10R carbon, whereas the S-Works frames are made utilizing Fact 12R. They additionally forego the Roval Rapide one-piece cockpit and the top-tier Roval Rapide CLX wheels, and thus the aero and weight advantages that they supply. 

Both tiers of the body are appropriate with digital groupsets solely. They characteristic a BSA threaded backside bracket, built-in cable routing, and clearance for 32mm tyres.

Specs and construct

Off-the-shelf builds can be found with Shimano Dura-Ace Di2 and Ultegra Di2, in addition to SRAM Red, Force and Rival. There isn’t any Shimano 105 Di2, neither is there a Campagnolo Super Record Wireless possibility. No 1X builds can be found off the shelf, however the entrance derailleur hanger will be eliminated and changed with a canopy to maintain issues tidy and minimise dust ingress when you’d want to go down this route. 

Both the Specialized (Fact 10R) and S-Works (Fact 12R) framesets are in the stores standalone. 

The S-Works builds include Dura-Ace or SRAM Red groupsets, and are fitted with Roval Rapide CLX II wheels and the Roval Rapide cockpit. In the Specialized body, Ultegra, Force or Rival groupsets are catered for, with the primary two getting Roval’s Rapide CL II wheelset and the two-piece aero handlebar, and the Rival-equipped spec getting Rocal C38 wheels and a spherical alloy handlebar. All bikes will likely be shipped with 26C tyres, in addition to the 15mm setback seatpost. (A 0mm possibility can be aftermarket).

The selection of crank size, stem size and bar width on all fashions is dependent upon the dimensions you purchase, and this leads me to my greatest gripe with the Specialized Tarmac SL8.

Unfortunately, there is not any pre-purchase customisation out there such as you get at Factor, Ridley, Colnago, or in Trek’s Project One programme to call a number of. If you might be my peak (6’2″ / 187cm) and trip a 58cm body, your bike will likely be fitted with 44cm huge handlebars and 175mm cranks. Based on the bike match I had final week, if I purchased a Tarmac SL8 as we speak, I’d have to promote the cranks and the cockpit and purchase shorter cranks, narrower bars, and an extended stem earlier than the primary mile had been ridden. 

I respect that is under no circumstances an issue unique to Specialized – in truth it is fairly a typical one, however as bikes get increasingly more costly, a model the dimensions of Specialized ought to lead from the entrance in relation to making life simpler for its clients, or they may take their spend elsewhere.  

Case in level, had I purchased a Factor Ostro, for instance, I may have chosen these specs earlier than shopping for, and had the bike how I needed it from the second it arrived, and never should take care of the stress (and possible monetary loss) of shopping for separate components and promoting my unused ones on Facebook or eBay.

Specialized does recognise that it is a drawback, and is counting on retail companions to make the decision on whether or not to swap out elements as a part of the gross sales bundle. To make it simpler, the cockpit is now even shipped in its personal retail packaging, moderately than free or hooked up to the bike. 

It’s a small step in the precise course, certain, however it’s not sufficient. Shops should not should make that decision, clients should not should hope the shop supervisor is in temper that day, and that answer solely accounts for the cockpit. It ignores crank size. 

If I’m spending $14k on a motorcycle from one of many greatest bike manufacturers on the planet, I ought to be capable of select which elements I get. 

Why not give me full customisation as an possibility, let me add my bike match knowledge, select my elements, swap out my tyres, and heck, whereas we’re at it let me improve to the flowery Roval Rapide CLX Team wheels, add some Supacaz bottle cages and throw in an S-Works Evade? I’d be comfortable to attend a month for all of it to reach as a result of I’ve most likely been dreaming about this buy for years anyway. 

Performance

If and if you ultimately get the Tarmac SL8 arrange the way you need it, you are in for an actual deal with. While it may be laborious to crown it the perfect, it’s totally comfortably among the finest highway bikes on the planet proper now.

In our wind tunnel check, the place we examined each with a rider after which with out, the Tarmac did not come out on the high of the pile in all checks, however it fared very effectively. 

I’ve already talked about that it got here out because the lightest on check. And within the tunnel with a rider, the Tarmac got here out quickest. The common CdA (Coefficient of drag x Area) throughout the varied yaw angles (the course that the wind hits the rider) was 0.3404, and in comparison with our baseline bike, would save 24.47 watts at 40km/h. The caveat to that end result, nevertheless, is that our margin for error was fairly excessive (because of the elevated variability attributable to the rider on the bike) and so statistically talking, the end result was a tie.

Without a rider, the place there was a smaller margin for error, the Tarmac landed a extra mid-pack end result, ending roughly 3 watts slower than the quickest on check, the Factor OSTRO VAM. Again, there are caveats, and on this case, it is that bikes do not pedal themselves, so this does not keep in mind any interplay between the bike and the rider’s legs. 

Regardless, for a motorcycle just like the Tarmac – the lightest on check – to take a seat amongst bikes just like the Trek Madone, Giant Propel, Scott Foil and Cervelo S5, it’s a strong end result that confirms its standing as among the finest in the marketplace. 

Coupling that knowledge with its trip high quality, the Tarmac continues to cement its place among the many frontrunners. 

As talked about earlier, those that have ridden the SL7 will get aboard the SL8 and really feel a way of familiarity. I’ve ridden the S-Works SL7, and I used to personal an S-Works SL6, so I felt proper at residence on the brand new bike in all its guises.  

Right from the primary trip again in 2023, and thru my use of the Force-equipped mannequin and latterly the Red-equipped S-Works mannequin, the factor that continues to face out is the bike’s dealing with. The Tarmac has by no means been unhealthy at going round corners. In truth, it is all the time been genuinely wonderful and even as we speak I daydream about my racing days railing hairpins on my SL6 and popping out of the nook carrying extra velocity than anybody round me (Turbo Cottons are nonetheless wonderful tyres). 

If you requested me the place I believed there may be room for enchancment when designing the SL8, dealing with could be proper on the backside of my record. 

But the Tarmac SL8 is one other degree above, particularly the S-Works fashions with the Roval Rapide one-piece cockpit. The new Pinarello Dogma F comes very shut, however nothing else I’ve ridden matches the telepathic immediacy it offers when hitting corners at velocity, like a guiding hand pulling you thru the apex.

When sprinting, each uphill and on the flat, the stiffness on the rear of the bike is great too. Given the pencil-thin seatstays and not-much-bigger chainstays, you would be forgiven for anticipating a little bit of flex by the rear of the bike, however it merely is not there. It’s not fairly as snappy and reactive because the light-weight Factor O2 on steep gradients (that bike largely advantages from the 1100g wheels), however if you determine it is time to boost the membership trip with a city signal dash, or it’s worthwhile to dash for the win in your native crit, the bike may be very a lot in its ingredient. 

It additionally confirms the extra invaluable perception that the underside bracket simply felt rock strong and the facility switch felt speedy. The front-end stiffness that aided the dealing with was additionally obvious right here in high-power efforts, yanking on the bars to get as a lot energy out as attainable, they only felt immovable. 

On the compliance and luxury entrance, nevertheless, it is price reiterating that it is a race bike. It’s stiff and purposeful so when you roll over a tough floor, you are going to learn about it. I’m not going to fake I can ‘really feel’ a 6% enhance in compliance however I did discover it to be snug. 

The logic of a shallower seatpost including compliance provides up, and my expertise with the bike does nothing to oppose the declare. I’ve completed brief rides, lengthy rides, races and extra aboard the Tarmac SL8, and never as soon as have I discovered it jarring. 

Value

At £12,000 / $14,000 for the S-Works fashions, with a slight uplift in some territories for the newer model of SRAM Red AXS, the worth tag of the Tarmac SL8 is rarely going to be deemed low cost. 

Crucially although, the worth is within the ballpark of its opponents. The actual comparisons rely in your spec selections and your territory, so I shan’t go into an excessive amount of element right here. American patrons will typically discover Italian manufacturers akin to Pinarello or Colnago costing extra on common, whereas European patrons will typically discover the alternative to be true. The Factor OSTRO is an fascinating consideration on this combine: the UK and USA worth undercuts that of similarly-specced Tarmac SL8 fashions, whereas providing the customisation of specs. 

And that is the place the Tarmac SL8 falls down probably the most, for my part. Your native bike store may permit you to swap out the cockpit, even perhaps the cranks, to make sure your new bike matches correctly, however you should not should depend on that. If you need to purchase it immediately from the Specialized web site, for instance, you are at the moment compelled into sure spec and geometry selections that to repair, will add to your total outlay. 

Verdict

The Specialized Tarmac SL8 isn’t the out-and-out lightest, the quickest, nor probably the most snug highway bike in the marketplace, however the way in which it combines these vital metrics to make a well-rounded high-performance superbike is spectacular.

The worth is not past that of its opponents. I simply want Specialized would evolve with the wants of its customers and supply a custom-build program when shopping for so that customers aren’t compelled to purchase elements they do not want or need. 

Once you get previous that hurdle although, the Tarmac is enjoyable, quick, light-weight, and its trip high quality is great. Its dealing with is unmatched, and we’ve got the info from the wind tunnel and the weighing scales to again up its place among the many finest highway bikes in the marketplace as we speak.