Specialized Tarmac SL8 Road Bike

An Introduction

Specialized has been pushing the boundaries of road bike technology for decades - refusing to stand still and resisting the urge to follow orthodoxy. Their work with aerodynamics, rider-focused geometries, and bleeding-edge material science has made them the manufacturer of the world's fastest race bikes. With the Specialized Tarmac SL8 Road Bike this has been pushed to an astonishing new level.

Specialized can now combine the lightest frame in the World Tour with aerodynamics better than the S-Works Venge. Read on to learn more about this exciting addition to the brand's illustrious Tarmac range.

Shop the Specialized Tarmac SL8 Road Bike and Frameset Range

Video is unable to play due to Privacy Settings.

Adjust your Cookie Preferences to Opt-in "YES" to "Functional Cookies".

Specialized S-Works Tarmac SL8 Frameset

What's New on The Specialized Tarmac SL8?

The most obvious change from the Specialized Tarmac SL7 Road Bike is the Tarmac SL8's massive reduction in weight. A 56cm size SL7 frameset weighs in at 800g, while the equivalent 56cm size SL8 is 685g, that’s a 14% drop bringing it into the realm of the lightest frames on the market.

Specialized revolutionised their frame-building process with the 585g Aethos, currently the world’s lightest production road bike. Using the same process they have delivered something mind-bending: a lighter frame than any of their competitors’ climbing bikes, in the shape of a full-blown aero bike. The Tarmac SL8 is the fastest aero bike Specialized has ever made, that’s right, faster on the flat than the legendary Venge. Hit even a tiny amount of gradient, and the bike's startlingly low weight comes into the picture, making clear its limitless potential for speed.

Specialized S-Works Tarmac SL8 Road Bike

The Specialized Tarmac SL8 Development Process

Specialized started the process to develop the Tarmac SL8 with help from their Ride Science team. The Ride Science team run complex simulations of the courses ridden in the World Tour, from high mountains to Flandrian bergs, Milan San Remo to Mont Ventoux, to determine the performance benchmarks required for a bike to truly be the fastest on earth. The reality was clear - they would need to deliver the most aerodynamic bike Specialized has ever produced, and at a lower weight than any bike currently racing the World Tour.

Specialized Tarmac SL8 Road Bike Seatstays

Making the Specialized Tarmac SL8

To craft a bike that was 14% lighter, 6% more compliant, 33% better in stiffness to weight and 16.6 seconds faster over 40km than the four-time World Championship winning Tarmac SL7, Specialized developed an entirely new design process they call Front-Loading Development. This process combines FEA* to perfect the physical structure and CFD* to tune the aerodynamics.

By running these two processes in a loop Specialized was able to test hundreds of possible configurations of carbon layup structure and monocoque shape before moving to physical construction, assured of being on the right track. Once construction itself began, they applied the 585-gram Aethos layup strategy to the new shape and began tweaking. 54 iterations later and the stiffness around the bottom bracket and headtube had been amplified, and the compliance of the rear triangle finely tuned. All targets were met, and the Tarmac SL8 was born.

*FEA or Finite Element Analysis is a simulation technique where engineers simulate physical phenomena using data-driven understanding of material properties. In this case with carbon!

*CFD or Computation Fluid Dynamics uses numerical analysis and data structures to solve problems involving fluid flows. Like aerodynamics!

Specialized Tarmac SL8 Rider First Demi Vollering

Specialized Rider First Engineered

Specialized has spent countless hours refining each size of the Tarmac SL8 to deliver a like-for-like balance of stiffness, weight, and ride quality. The Rider-First Engineered SL8 used extensive data acquisition of forces through every part of the frame during real-world testing to make achieving this balance a certainty. There’s a new Tarmac for you whatever your height, with each being designed to be the fastest bike of that size possible.

Specialized bike fit date determined there can be as big a difference between two male cyclists as there might be between a male and female. The Tarmac SL8 is the second generation to eliminate gendered bikes and offer instead the range of sizes needed to accommodate everyone.

Specialized S-Works Tarmac SL8 Road Bike

What Specialized Tarmac SL8 Models are Available?

The Tarmac SL8 will be launched with S-Works, Pro and Expert complete bikes as well as FACT 12r and 10r framesets.

The S-Works model will use the top end 12r carbon frame weighing 685g in the lightest colourway (Satin Carbon/Chameleon Snake Eye) with a 56cm frame. It will ship with a Roval Rapide Cockpit, Roval Rapide CLX II wheels and either Shimano Dura-Ace Di2 or SRAM Red AXS.

The Pro models will use the FACT 10r frame weighing 780g, the Tarmac SL7 stem/Roval Rapide handlebars, Rapide CL II wheels and either Shimano Ultegra Di2 or SRAM Force AXS.

The Expert models will use the FACT 10r frame, Tarmac SL7 stem/Specialized Expert Alloy Handlebars, Roval Rapide C 38 wheels and Rival AXS.

Complete bike weights are approximately as follows: S-Works Di2 - 6.6kg | S-Works AXS - 6.8kg | Pro AXS - 7.4kg | Pro Di2 - 7.2kg | Expert AXS - 7.7kg.

These weights may vary based on colourway, size, and final fit configuration. All specifications are at launch and subject to change.

Shop all Specialized Tarmac SL8 Road Bikes and Framesets

Specialized Tarmac SL8 Road Bike Fork


The Tarmac SL8 is only compatible with electronic drivetrains and hydraulic disc brakes. It can take a maximum 55/42 tooth chainrings and has room for powermeter pods on both sides. It can take up to 32 millimetres tyre with 4 millimetres of clearance. It can be run in a 1x configuration with an adaptor provided for the cleanest possible setup. It is backwards compatible with 11 speed Shimano Di2.

All Tarmac SL8 models have a 68mm BSA threaded bottom bracket. The Tarmac SL8 has 142x12 and 100x12 dropouts and follows the Shimano flat mount disc brake standard for 140/160mm rotor in the rear. The front brake is only compatible with 160mm and with flat mount brake calipers.

The Tarmac SL8 has a 1 1/8” steerer tube and was designed for use with the one-piece Roval Rapide cockpit or the Tarmac SL7 stem. Riders can use any handlebar with a 31.8mm clamp diameter with the Tarmac SL7 stem.

Who is the Specialized Tarmac SL8 For?

The Tarmac has been the racer's race bike for a generation. In that time it has only gotten faster. Yet having the fastest race bike hasn’t been the only goal for a long time now. Why build something that good if everyone can’t use it? The SL8 is a massive step forward in terms of what’s possible from a race bike. Lighter than a climbing bike, whilst at the pinnacle of cycling aerodynamics. Even more it is another step forward in comfort, keeping the rider fresher for longer and with a model that will fit everyone.

Shop the Specialized Tarmac SL8 Road Bike and Frameset range

Find more articles tagged with:

Bikes Launches Specialized Bike Reviews