Typically you can expect bike reviews on Escape Collective to be exhaustive and as a result, long. While this is no different, so much to know about the new Tarmac SL8 has already been covered in our initial bike release and build report.
Consider this review the expansion pack to that original coverage. Here, you’ll find a short refresher of the bike plus how I’ve gotten along with it over the past few months, including the ride to expect, thoughts on the parts equipped with the second-tier Pro model, and the few shortcomings. For everything else, go check that article from August 2023.
Lows: Stock handlebar width isn’t aero, messy Di2 integration for rear derailleur, upgrade to one-piece cockpit requires spare steerer length, gap beneath headset top cover, round spokes are a cost-saving measure.
Total weight: 7.11 kg / 15.7 lb (without pedals or cages, but with computer mount and tyre sealant)
Price: US$8,500 / AU$11,900 / €8,500 / £8,000
A quick recap
Only a handful of road bike models on the market attract quite as much attention as the Specialized Tarmac. A big part of that is the company's ability to create a lot of noise, but no matter how big the megaphone is, they still need something to say. And as one of the consistently best-selling road models, the Tarmac has earned a reputation for being a damn good road race bike.
Wind back three years and Specialized’s Tarmac SL6 was well regarded as a fantastic riding bike. It offered lively handling, it was light, stiff enough, and comfortable for riding all day. It had some aero cues, but its visible brake hoses had it looking slightly dated by the time it was superseded. Along a similar timeline was the Specialized Venge, a dedicated aero road bike that was arguably the faster option, and yet, many of Specialized’s top pros, such as Peter Sagan and Julian Alaphilippe, would more commonly still pick the Tarmac SL6.
Then came the Tarmac SL7, a road bike that promised to be everything the Venge was, but with a weight close to the SL6. The SL7 looked a whole lot like the Venge, and Specialized included new wheels (Roval Rapide) and an updated cockpit to tell a story of the Tarmac being faster than the now-superceded dedicated aero bike. And despite a shaky start with a voluntary safety recall, the Tarmac SL7 was, and still is a great bike.
Finally, we come to Specialized’s latest all-rounder race bike, the Tarmac SL8. It’s a bike that retains the same proven geometry figures as SL6, Venge, and SL7 before it, yet it’s claimed to be lighter, stiffer, smoother-riding, and a smidge more aero than all before it.
The structural lessons are said to be learned from the Californian company’s lightweight Aethos. More cynically, they're lessons learned before the pursuit of making every tube into a truncated airfoil became the priority of the modern road market. Indeed, the top tube, down tube, and chainstays have had the clock wound back and are now close to shapely cylinders. Meanwhile, the aerodynamic gains of the SL8 are subtle, with as much as 80% of the claimed 5 watt-improvement (compared to the SL7) attributed to the new one-piece Roval Rapide cockpit of the S-Works model (claims are without a computer mount in place). The remaining gains are in the fork legs that are now more similar to the discontinued Venge, a slimmer seat tube and seatpost combo, and a head tube that stole the show.
The head tube is elongated forward of the steerer tube. Specialized humorously named it the Speed Sniffer, and indeed, the nose-looking shape aims to create a narrower frontal profile for the air ahead to smoothly attach to rather than first hit a big bulbous head tube. No doubt there’s something to the design, which is probably why both Pinarello and Trek have used similar concepts before, too.
“With a rider on the bike, the leading edge is what matters most for aero – that’s why the cockpit, fork legs, and head tube were optimized accordingly,” said Specialized’s road product manager Miles Hubbard when asked why the rest of the bike was arguably made less aero. “Truncated tubes elsewhere on the bike can negatively impact weight and ride quality thus making for a slower package overall,” added Hubbard, while pointing to the company’s SL8 white paper for a deeper explanation. Either way, it appears Specialized is now saying #aeroisnoteverything (niche bike dork joke).
OK, so unless you’ve got access to an accurate wind tunnel or are willing to spend countless hours Chung’ing it with Golden Cheetah, the new SL8 is arguably undetectably as aero as the SL7. That’s certainly true for the SL8 Pro version tested here which features an identical two-piece bar and stem to the former flagship SL7. Meanwhile, the statement also remains rather true if you were to put the new Roval Rapide one-piece cockpit (as supplied with the SL8 S-Works) onto an older SL7. Unfortunately, at Escape Collective, we’re no closer to putting exact aero numbers to bikes, and so I can’t offer any useful insight into how the SL8 may compare to similar lightweight do-it-all race bikes such as the Cannondale SuperSix Evo, Canyon Ultimate CFR, or the like.
Did we do a good job with this story?
