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.
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
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"
California Prop 65 Warning:
This product may contain chemicals known to the state of California to cause cancer and birth defects or other reproductive harm. (California law requires this warning be given to customers in the state of California.)
California CBE Fees:
Some products we sell may be subject to California’s Covered Battery-Embedded (CBE) Waste Recycling Fee (effective January 1, 2026) when a product contains a non-removable rechargeable battery. If applicable, the fee (1.5% fee with a $15 max per item) will either be added to your cart as a separate line item or be invoiced after your order is placed and before it can be fulfilled.
