Specialized Tarmac SL8 first ride review - The gold standard

The release of the new Tarmac SL8 is likely one of the most highly-anticipated launches of the entire season. We were drip fed glimpses of the new model through sneaky snaps of Soudal-Quick Step training camps and underground leaks on websites which only elevated anticipation around the new bike. The main question was: how was Specialized going to improve a bike that is already the favourite of so many? Where would the Tarmac go next? And would it be much different, or any better?

There are three key places where Specialized has focused its attention when it comes to the SL8: aerodynamics, weight and ride quality. All of these combine to make a very fast bike, but the challenge is creating the equilibrium where improving one element doesn’t mean sacrificing another. Often, improved aerodynamics mean extra weight and an aggressive, uncomfortable position, which means a worse performance on the climbs, while lightweight bikes can feel slow and unsupportive on the flat. Bike manufacturers have been on a quest to get this equation right for some time now. With the SL8, Specialized believes it has cracked it.

Taking influences from both the ultra-lightweight Atheos and the ultra-aerodynamic Venge, Specialized says that the SL8 is the most aero road bike it has ever created, as well as the lightest on the WorldTour. In addition to the bike’s impressive aero and weight credentials, Specialized are also claiming a huge 33% improvement on stiffness-to-weight ratio which should rapidly improve ride feel. This is all while retaining the same geometry as the SL7, something that die-hard Tarmac fans will be very happy to hear.

A few days before the Specialized S-Works Tarmac SL8 was released into the world, we were able to take it for a spin on the roads of Dorking near Specialized’s headquarters in the UK. While we only spent a couple of hours on the bike, there were still some key takeaways from the ride. The biggest one being that we wished we could take it home with us…

Ride impressions

As soon as I hopped on the SL8, I was impressed with the fit immediately. It normally takes me a little while to get used to a bike, but I felt as if the geometry of the SL8 was extremely balanced. Specialized says it uses Retul data to inform its Rider-First Engineered frames, so it is perhaps unsurprising that the SL8 carries through that same comfortable fit that has always made the Tarmac popular. 

The bike I rode featured the integrated Rapide cockpit which I was also impressed by, despite having no bar tape on the top of the bars, the textured, matt feel meant that my hands weren’t ever at risk of slipping off the carbon. The shape of the bars suited me well too, with the radius from the tops to drops always giving enough wrist clearance both in and out of the saddle. The Rapide integrated bar and stem also looks clean at the front of the bike and has aerodynamic benefits, not to mention feeling extremely stiff when under load completing sprint efforts. With 15 different bar and stem combinations, Specialized offers a range of fit options for all here.

The neat look of the cockpit is carried out through the entire bike, no cables are visible and the matt white colour I tested is eye-catching while also being simple and classic, though it was already looking a bit grubby after just one ride, so keep in mind the maintenance required to keep a bike that colour looking fresh.

One of the key criticisms of the previous iteration Tarmac SL7 was its firm feel that put you heavily in touch with the road surface. After the end of a long ride, it was not a bike that felt especially comfortable on rougher tarmac. With the SL8, however, Specialized has certainly addressed and conquered this issue. The roads in the south of England are unforgiving and the punchy climbs and steep descents are often littered with potholes meaning that they will really put a bike through its paces, and any bike too stiff is exposed very quickly. The SL8 felt like it was dampening out any vibrations, extremely compliant and almost floating over rough roads, the narrow seat stays and seatpost at the rear of the bike allowing for much more flex and comfort when hitting bumps.

The stiff front of the SL8 meant it was really responsive to accelerations, it felt like I had to put very little effort into the bike to get it moving fast. The way that Specialized has cut weight at the rear of the bike makes it feel really snappy in combination with the stiff front end. Miraculously, Specialized has created a bike that flies up climbs thanks to its light weight but also rolls extremely quickly on the flat – helped by the wide internal rim width of the Roval Rapide wheels. The wider tyres make the bike feel more comfortable too as well as giving a better rim profile, and the wheels handled extremely well in the wind considering their depth. The impressive 685 gram weight of the frameset also means you can now ride deeper wheels without taking so much of a weight penalty to the overall bike, while you could opt for wheels like the Roval Alpinist model for an extremely light bike that would undoubtedly feel even better on the climbs.

While I haven’t been able to back up the science of aerodynamics in a wind tunnel, I can ascertain that the SL8 feels extremely fast from the off, holding speed nicely and effortlessly when rolling along the flat. When it comes to the corners, the SL8 did exactly as I asked of it; it was very responsive but didn’t feel twitchy either, especially when comparing to older aero bikes which are often too stiff and have bigger tubes that are generally a lot harder to handle. The bike I rode was equipped with a Shimano Dura-Ace groupset (a full review of this here) that shifted quickly and allowed me to break sharply, something that I felt gave me the confidence to really put the SL8 through its paces. 

I always try to find some constructive criticism to balance out a review, but with the Specialized Tarmac SL8, I’m honestly struggling to find anything I didn’t like about the bike. I haven’t tested it for longer than a two hour spin so can’t comment on its durability or how easy it is to maintain, but I came away from the ride just wishing I could spend more time on it. While still a premium price point for a premium bike – £12,000 for the S-Works specification I rode – Specialized has even managed to lower its prices when compared to the SL7. The Specialized SL8 in ‘Expert’ spec retails for £6000, a reasonable price for a bike so advanced and when considering the fact that the Tarmac is an all-rounder that can serve as one bike to do it all.

The Specialized Tarmac SL8 looks good, feels good and is even more aerodynamic than the Venge, and it really poses the question, is there any reason to have another bike? Maybe the Aethos is still an option for a super lightweight, less racey and more classic looking machine, but I feel as if the Tarmac SL8 is another big, big win from Specialized.

(Note: The bike pictured is a display bike with the same frame, bars, wheels and groupset as reviewed but it is not the exact bike that was ridden by our journalist.)