Specialized Tarmac SL8 Expert Ultegra Di2 Bicycle – The fastest road bike in the world
No bike is as fast as the Tarmac SL8, thanks to a revolutionary mix of aerodynamics, lightness, and handling. After eight generations and decades of refinements, it’s not just the fastest Tarmac ever: it’s the fastest road bike in the world. Ready to harness every watt?
Why choose it:
Advanced aerodynamics: every profile is optimized in the Wind Tunnel to reduce drag. The fork steerer is set back from the head tube to limit turbulent airflow. New UCI rules have allowed for a super slim and aerodynamic seatpost.
Extreme lightness: the frame weighs about 685 g, 15% less than the SL7. It is lighter than any bike in the WorldTour*, thanks to structural choices inspired by the Aethos project.
Superior ride quality: the stiffness-to-weight ratio is improved by 33% compared to the SL7. It offers precision, responsiveness, and comfort – better filtering road vibrations for a stable and agile cornering feel.
Expanded versatility: retains the geometry of the previous model with clearance for tires up to 32mm, to suit various road scenarios.
“Beyond gender” approach: designed for the cyclist, not the cyclist's gender. Every rider, male or female, can benefit from the Tarmac SL8.
The SL8 Expert Ultegra Di2 version features a Shimano Ultegra Di2 groupset, Roval C38 tubeless ready wheels, integrated SL7 stem, and Specialized Expert Shallow Drop handlebar – a complete setup for those seeking high performance without compromise.
Technical Specifications
Frame & Suspension
Frame: Tarmac SL8 FACT 10r Carbon, Rider First Engineered™, Win Tunnel Engineered, clean internal routing, threaded bottom bracket, rear axle 12×142 mm, flat-mount brake support
- Fork: FACT 10r Carbon, 12×100 mm, flat-mount support
Brakes
Drivetrain
Shifters: Shimano Ultegra Di2 R8170 (hydraulic)
Front derailleur: Shimano Ultegra Di2 R8150 (braze-on)
Rear derailleur: Shimano Ultegra Di2 R8150, 12-speed
Cassette: Shimano Ultegra, 11-30T
Chain: Shimano XT M8100, 12-speed with quick-link
Crankset: Shimano Ultegra R8100, 52/36T
Bottom bracket: Shimano threaded BSA
Wheels & Tires
Wheels: Roval C38, carbon rim with 21 mm internal width
Tires: S-Works Turbo 700×26 mm, 120 TPI, folding bead, BlackBelt protection
Inner tubes: Turbo Ultralight, Presta valve 48 mm
Cockpit & Saddle
Stem: integrated Tarmac, 6° angle
Handlebar: Specialized Expert Shallow Drop (alloy), 125 mm drop / 75 mm reach
Handlebar tape: Supacaz Super Sticky Kush
Saddle: Body Geometry Power Expert
Seatpost: S-Works Tarmac SL8 Carbon, FACT Carbon, 15 mm offset
Seat collar: integrated wedge type
Additional Details
Note Well
Technical specifications may change without notice depending on component availability.
Product images are for illustrative purposes only and may not exactly reflect the described features.
Choose the Specialized Tarmac SL8 Expert Ultegra Di2 and experience every ride with maximum speed, efficiency, and control: the ultimate road bike for ambitious cyclists.
Do you want to receive your bike ready for use? Don't forget to add the bike assembly service at the time of purchase! Discover all the details here: Francesconi bike assembly
A Complete Guide to Bike Sizes
Foreword: Not all bike sizes are the same
Each type of bike has a specific frame and often uses a different size scale. For example, a road bike with a 54cm frame might be considered a medium size by one brand, but a large by another.
Bicycle adjustment margins
Some types of bikes, like gravel bikes, offer a wide range of adjustments, adapting to different body types. Other models, however, have limitations in this regard. This is an important aspect to consider.
How to use size charts
We've created a simple guide to help you find the right bike size:
- Check out our size charts for each bike type.
- Learn more with specific tips to help you make the right choice.
Size Charts: Find Your Perfect Bike
Gravel and road bikes
Sizes are based on the length of the top tube (in cm), which determines the reach of the bike.
| Cut
|
Recommended height
|
Horizontal tube length
|
| XS |
Up to 157 cm |
48-50 cm |
| S |
157-167 cm |
50-53 cm |
| M |
168-178 cm |
53-56 cm |
| THE |
178-185 cm |
56-58 cm |
| XL |
Over 185cm |
58-62 cm |
For gravel, measurements may vary slightly due to different geometries, but remain similar.
Mountain bike
MTBs are measured in inches, based on the seat tube.
| Cut
|
Recommended height
|
Size (in inches)
|
| XS |
Up to 157 cm |
14"-16" |
| S |
157-167 cm |
15"-17" |
| M |
168-178 cm |
16"-19" |
| THE |
178-185 cm |
18"-20" |
| XL |
Over 185cm |
20"-23" |
Sizes also vary depending on the type of MTB: full-suspension , hardtail or fat bike .
Children's bikes
The size depends on the size of the wheels, often associated with age:
| Age
|
Wheel Size
|
| 1-3 years |
12" |
| 2-4 years |
14" |
| 4-6 years |
16" |
| 5-8 years |
20" |
| 8-10 years |
24" |
| Over 10 years |
26"/27.5" |
What to do with half measures?
If you are between two sizes:
-
Comfort : Choose the larger size.
-
Performance : Go for the smaller size.
Final tips for choosing
-
Consult the manufacturer's instructions : Always check the brand's guidelines.
-
Ask an expert : a specialized workshop can help you choose based on your height, ideal reach and goals.
-
Test the bike : If possible, test the model you intend to purchase.
