
2025 Specialized Tarmac SL8 Expert - Ultegra Di2 Features
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.
At a Glance
- AERO IN EVERYTHING: We’re putting aero where it matters - the leading edge - not just where it looks good. In the process we’ve 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 we’ve 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.
- 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.
Component Specifications
| Frame | Tarmac SL8 FACT 10r Carbon, Rider First Engineered™, Win Tunnel Engineered, Clean Routing, Threaded BB, 12x142mm thru-axle, flat-mount disc |
| Seat Binder | Tarmac integrated wedge |
| Fork | FACT 10r Carbon, 12x100mm thru-axle, flat-mount disc |
| Shift Levers | Shimano Ultegra Di2 R8170, hydraulic disc |
| Front Derailleur | Shimano Ultegra Di2 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 |
| Chain Rings | 52/36T |
| Bottom Bracket | Shimano Threaded BSA BB |
| Front Tire | S-Works Turbo, folding bead, 700x26mm |
| Rear Tire | S-Works Turbo, folding bead, 700x26mm |
| Inner Tubes | Turbo Ultralight, 48mm Presta valve |
| Front Brake | Shimano Ultegra Di2 R8170, hydraulic disc 160mm rotor |
| Rear Brake | Shimano Ultegra Di2 R8170, hydraulic disc 140mm rotor |
| 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 |
2025 Specialized Tarmac SL8 Expert - Ultegra Di2
| Bike/Frame Size | 44 | 49 | 52 | 54 | 56 | 58 | 61 |
|---|---|---|---|---|---|---|---|
| Frame Stack | 501 mm | 514 mm | 527 mm | 544 mm | 565 mm | 591 mm | 612 mm |
| Frame Reach | 366 mm | 375 mm | 380 mm | 384 mm | 395 mm | 402 mm | 408 mm |
| Fork Rake/Offset | 47 mm | 47 mm | 47 mm | 44 mm | 44 mm | 44 mm | 44 mm |
| Front Center | 572 mm | 574 mm | 577 mm | 579 mm | 592 mm | 606 mm | 613 mm |
| Chainstay Length | 410 mm | 410 mm | 410 mm | 410 mm | 410 mm | 410 mm | 410 mm |
| Wheelbase | 970 mm | 973 mm | 975 mm | 978 mm | 991 mm | 1006 mm | 1013 mm |
| Top Tube Length, Horizontal | 496 mm | 509 mm | 531 mm | 541 mm | 563 mm | 577 mm | 595 mm |
| Bike Standover Height | 723 mm | 735 mm | 746 mm | 768 mm | 786 mm | 808 mm | 834 mm |
| Seat Tube Length | 433 mm | 445 mm | 456 mm | 473 mm | 494 mm | 515 mm | 545 mm |
| Seat Tube Angle | 75.5° | 75.5° | 74° | 74° | 73.5° | 73.5° | 73° |
| Stack to Stem | 509 mm | 522 mm | 535 mm | 552 mm | 573 mm | 599 mm | 620 mm |
| Reach to Stem | 363 mm | 372 mm | 377 mm | 381 mm | 393 mm | 400 mm | 406 mm |
| Head Tube Length | 99 mm | 109 mm | 120 mm | 137 mm | 157 mm | 184 mm | 204 mm |
| Head Tube Angle | 70.5° | 71.75° | 72.5° | 73° | 73.5° | 73.5° | 74° |
| BB Height | 266 mm | 266 mm | 266 mm | 268 mm | 268 mm | 268 mm | 268 mm |
| BB Drop | 74 mm | 74 mm | 74 mm | 72 mm | 72 mm | 72 mm | 72 mm |
| Trail | 71 mm | 63 mm | 58 mm | 58 mm | 55 mm | 55 mm | 52 mm |
| Fork Length, Full | 370 mm | 370 mm | 370 mm | 370 mm | 370 mm | 370 mm | 370 mm |