X-LAB RT9 Lightweight Performance
In stock at 1 shop in Los Angeles
Prices and stock checked Oct 22.
Where to buy
1 shopAbout this bike
- Stock Update 5/19/2026
- We are anticipating RT9s to be restocked in June.
- X-Lab Rt9
- The lightest production road frame ever built.
The RT9 redefines what is possible in lightweight performance engineering. Constructed from Toray T1100 carbon and refined through extensive structural analysis, the frame weighs an astonishing 550 grams while maintaining the stiffness and durability required for elite racing. The RT9 is the lightest production road bike frame in the world. Period.
Show full description and specs
The 550g Frame to Defy Gravity
When the goal is pure elevation, grams matter. The RT9 begins with a frame engineered to ~550 grams, built to feel weightless on the steepest pitches while staying composed under real-world power.
A Cockpit Built for Switchbacks
Every touchpoint is designed for climbing: a lightweight, responsive integrated cockpit that keeps the front end precise when the road turns vertical and the pace turns personal.
Seamless Integration, Elite Efficiency
From seatpost to tube junctions, RT9’s integration is obsessively refined to complement an all-out climbing machine with cleaner lines, cleaner airflow, and a ride that feels like perpetual poetry in motion.
Key Features
- Branta C50 ULR carbon wheelset with carbon spokes | 1,230 g
- Branta carbon crankset with integrated power meter + Apple Find My anti-theft technology
- Shimano Dura-Ace groupset
- XDS carbon frameset with Toray T1100, Full bike 6.2kg
Build Kit
- Frame
- XDS Carbon Frame, Toray T-1100 + M40X, UDH Compatible
- Fork
- XDS Carbon Fork, Toray T-1100, 100x12mm Thru-axle
- Handlebar / Stem
- Branta Carbon Integrated
- Seatpost
- XDS Carbon Seatpost, 27.2mm
- Rear Derailleur
- Shimano Dura-Ace RD-R9250 Di2
- Front Derailleur
- Shimano Dura-Ace FD-R9250 Di2
- Shifters
- Shimano Dura-Ace ST-R9270 Di2
- Brakes
- Shimano Dura-Ace BR-R9270
- Cassette
- Shimano Dura-Ace CS-R9200, 11-34T
- Crankset: Branta Carbon Power Meter Crankset, 52-36T, 29mm Alloy Spindle, Apple Find My Anti-Theft Technology
- Bottom Bracket
- BSA 29mm
- Rotors
- Shimano SM-MT900, F:160mm R:140mm
- Chain
- Shimano CN-M9100
- Wheelset
- Branta C50 ULR, Carbon Rims & Spokes
- Tires
- Michelin Pro 5 700x28C
- Saddle
- Selle Italia SLR Boost, Carbon Rails
- Weight
- 6.20 kg / 13.64 lbs (Size L)
- Size Options
- XS / S / M / L
- Sizing
- X-Lab recommends the following sizes based on rider height:
- XS
- 4'10" - 5'2"
- S: 5'2" - 5'6"
- M: 5'6" - 5'9"
- L: 5'9" - 6'0"
