Specialized Tarmac SL8 Expert Shimano Ultegra Di2 2025
Nothing is faster than the Tarmac SL8 thanks to a combination of aerodynamics, lightweight, and ride quality previously thought impossible
After eight generations and over two decades of development, it’s more than the fastest Tarmac ever - it’s the world’s fastest race bike. Your legs up for it? Aerodynamics or lightweight alone don’t win races - speed is what matters. Delivering that speed requires creating an uncompromising combination of aerodynamics, lightweight, stiffness, and compliance. Through race simulations using real world data our Ride Science team knows the Tarmac SL8 is the fastest race bike ever made on the routes that matter - 16.6 seconds faster over 40km, 128 seconds faster over Milan San Remo, 20 seconds faster over the legendary Tourmalet climb. The Tarmac SL8 Expert Di2 delivers exceptional performance with a full Ultegra Di2 groupset, C38 carbon tubeless ready wheelset, and an SL7 stem with Specialized Expert Shallow Drop alloy handlebars makes for an accessible performance-packed bike
Aero in everything
Specialized is putting aero where it matters - the leading edge - not just where it looks good. In the process Specialized has created our most aerodynamic road bike ever. Yes, it’s more aero than the Venge. Clean air is optimized for maximum advantage with the Tarmac’s new nose cone - the Speed Sniffer. By moving the steer tube back - the tube that determines head tube width - the leading edge of the head tube can be much sharper, delivering a much lower drag shape. Utilizing new UCI rules, the Tarmac SL8 has the narrowest, most aero seat post Specialized has ever made ensuring fast moving, dirty air around the legs can flow back more cleanly. Doesn’t victory smell sweet?
Minimum weight, maximum aero
Tarmac SL8 took learnings from Aethos to be easily built at the UCI minimum with a full aero set up. The team delivered a mind bending, scale tickling 685 gram frame - 15% lighter than the Tarmac SL7 and lighter than anything on else on the World Tour*. With the ability to make lightweight a top priority in the down tube, seat tube, and rear of the bike lessons from Aethos were applied. The frame’s shape carries load so efficiently that extra carbon stiffness layers become redundant. *Unless of course you count the time Kasper Asgreen raced our 585 gram Aethos frame during a Tour stage.
Goes like hell, rides like heaven
With massive gains in stiffness-to-weight - an improvement of 33% over the SL7 - the Tarmac SL8 takes legendary handling, aggressive responsiveness and World Championship proven geometry to the next level. The bike is stiffer at the pedals, more precise at the bars, and combines it with a compliant ride in the saddle that sets a new benchmark for race bike comfort. Thanks to our Rider-First Engineering, every rider, regardless of size, gets the same unprecedented ride quality and handling. In the saddle the Tarmac SL8 delivers 6% more compliance, floating over rough road with a supple feel unique in the high strung world of race bikes. Tarmac’s proven geometry and 32mm tire clearance are identical to the SL7, ensuring easy adaptation and the versatility to run higher volume tires when needed.
Beyond gender
There can be more difference between two male cyclists than between a male and female. Gender alone doesn’t provide nearly enough data to specialize and that means creating male or female bikes is arbitrary and outdated. Every rider can get the next level advantage of Tarmac SL8. It’s time to go Beyond Gender.
Tech Specs
Frameset
- Frame: Tarmac SL8 FACT 10r Carbon, Rider First Engineered™, Win Tunnel Engineered, Clean Routing, Threaded BB, 12x142mm thru-axle, flat-mount disc
Suspension
- Fork: FACT 10r Carbon, 12x100mm thru-axle, flat-mount disc
Brakes
- Front Brake: Shimano Ultegra Di2 R8170, hydraulic disc
- Rear Brake: Shimano Ultegra Di2 R8170, hydraulic disc
Drivetrain
- Shift Levers: Shimano Ultegra R8170, hydraulic disc
- Front Derailleur: Shimano Ultegra R8150, braze-on
- Rear Derailleur: Shimano Ultegra Di2 R8150, 12-speed
- Cassette: Shimano Ultegra, 12-speed, 11-30t
- Chain: Shimano Ultegra, 12-speed
- Crankset: Shimano Ultegra R8100
- Chainrings: 52/36T
- Bottom Bracket: Shimano Threaded BSA
Wheels & Tires
- Front Wheel: Roval C38, 21mm internal width carbon rim
- Rear Wheel: Roval C38, 21mm internal width carbon rim
- Front Tire: S-Works Turbo, folding bead, 700x26mm
- Rear Tire: S-Works Turbo, folding bead, 700x26mm
- Inner Tubes: Turbo Ultralight, 48mm Presta valve
Cockpit
- Tape: Supacaz Super Sticky Kush
- Stem: Tarmac integrated stem, 6-degree
- Handlebars: Specialized Expert Shallow Drop, alloy, 125mm drop x 75mm reach
- Saddle: Body Geometry Power Expert
- SeatPost: S-Works Tarmac SL8 Carbon seat post, FACT Carbon, 15mm offset
- Seat Binder: Tarmac integrated wedge
Weight
- Producer's weight: 7.20kg (15 lb, 14 oz)
- Weight Size: 56
Producer's note: Weights based on production painted frames as pictured. Actual weights will vary based on colourway, frame size, and component variation. Specifications are subject to change without notice.