Rocket Goat is the fourth bike in our Sierra Bicycle Supply Custom Build Series — a celebration of cool, fun builds that ride as good as they look. Builder Nathan Troyer designed this one as a road racer with stealth climbing ability.
Finished in the Satin Carbon/Super Red Pearl colorway, this 2026 Specialized Tarmac SL8 is equal parts racer and climber.
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.
Technical Specifications
Frameset
Frame: Tarmac FACT 10r Carbon, Rider First Engineered™, threaded BB, 12x142mm thru-axle, flat-mount disc
Fork: FACT Carbon, 12x100mm thru-axle, flat-mount disc
Brakes
Front Brake: SRAM Force AXS, E1 hydraulic disc, 160mm Paceline Rotors
Rear Brake: SRAM Force AXS, E1 hydraulic disc, 160mm Paceline Rotors
Drivetrain
Shift Levers: SRAM Force AXS 2X E1 Electronic HRD
Front Derailleur: SRAM Force AXS E1, braze-on with SRAM battery
Rear Derailleur: SRAM Force AXS Rear Derailleur – 12-Speed, Short Cage, 36t Max, Black, E1, with SRAM battery
Cassette: SRAM Force XG-1270, 12-speed, 10–36t, silver (DT Swiss Ratchet XDR driver body, E1)
Chain: SRAM Force E1 12-speed, 114, silver
Crankset: SRAM Force E1 Crankset with Power Meter Spider, 165mm, 2x12-speed, 50/37T thread mount
Bottom Bracket: SRAM DUB BSA 68/73
Wheels & Tires
Front Wheel: Roval Alpinist CL II, 21mm internal width carbon rim, 33mm depth, DT for Roval 350 hub, DT Swiss Aerolite spokes, tubeless
Rear Wheel: Roval Alpinist CL II, 21mm internal width carbon rim, 33mm depth, DT for Roval 350 hub, DT Swiss Aerolite spokes, tubeless
Front Tire: S-Works Turbo TLR Race, Black, 700x30mm – Tubeless
Rear Tire: S-Works Turbo TLR Race, Black, 700x30mm – Tubeless
Cockpit
Stem: Integrated
Handlebars: Roval Rapide Cockpit 100mm x 40cm
Tape: ZIPP Service Course Bar Tape X Black
Saddle: Specialized Roman Evo Pro with Mirror, 143mm
Seatpost: S-Works Tarmac SL8 Carbon seat post, FACT Carbon, 15mm offset
Seat Binder: Tarmac integrated wedge
Weight
Weight: 15.74 lbs (Size 54)
