Specialized Tarmac Compared

At 685g, the S-Works Tarmac SL8 frame is 15% lighter than the SL7 while retaining its signature, race-proven aerodynamic design. To cut weight even more, engineers at Specialized took their experience designing the Aethos (Specialized’s “so light it’s illegal” climbing bike) and used it to create the carbon layup on the SL8. Weighing in at a mere 14.6 lbs, the S-Works Dura-Ace build (56cm) is so light that it can’t be raced professionally. But let’s not forget... this is not a “climber’s bike;” it still has deep aero wheels and an integrated aero cockpit.

Depending on your budget and how much weight and aerodynamics matters to you, there is a Tarmac SL8 to suit your needs. The S-Works model features the lightest components on the market coupled with aero-focused features such as the Rapide CLX wheels and the one-piece bar and stem Rapide Cockpit. With electronic shifting, you can expect the performance to be very similar between all the tiers so the differences between groupsets are mostly down to weight.

Both version of the Tarmac SL8 frame are identical in appearance. The only difference is in the carbon layup which makes the 12r S-Works model around 270 grams lighter than the 10r model. Keep in mind that these weight values are just estimates – frame weights can vary due to manufacturing idiosyncrasies or simply different paint and finish options. The lightest SL8 frame option is the Ready-To-Paint (RTP) Frameset which features a raw carbon finish and is 40g lighter than most painted S-Works frames.

The SL8 took the incredible design of the SL7 and refined it – cutting weight and still prioritizing aerodynamics. While the “Speed Sniffer” head tube is the first thing to draw your attention, some of the biggest changes with the SL8 can be found at the rear end. The SL8 takes inspiration from the Aethos and boasts a slimmed-down rear triangle, a smaller seatpost, and new rail clamp to maximize weight savings. Despite the appearance modifications, the SL7 and SL8 both share identical geometry – so riders can easily migrate between the two frames.

While the SL8 frame design focused on weight savings, it appears that the single biggest contribution to aerodynamic performance on the S-Works SL8 actually comes from the Roval Rapide Cockpit. With a claimed 4 watts savings over a traditional road aero bar, the Rapide Cockpit is a 1-piece full-integrated stem and bar combo that cuts through the air like no other. And the best part? You can buy the Rapide Cockpit and add it to your SL7 or lower-tier SL8. At $599.99, it’s not exactly cheap, but it’s an easy way to obtain S-Works-level gains without dropping S-Works-level cash.