KOIBIKE R50X26TL-UL Carbon Road Rim : 

The KOIBIKE R50X26TL-UL is a 50mm-deep, 26mm-wide carbon fiber road wheel. Designed with lightweight, aerodynamic, and structural rigidity in mind, each rim weighs just 475±15g to reduce rotational drag and enhance climbing speed and agility. This makes it one of the lightest 50mm rims in its class. The rim's wide and high design, combined with a truncated airfoil aerodynamic section, has been wind-tunnel-verified to reduce drag by 10% at 40 km/h and conserve rider energy at a cruising speed of 45 km/h. Furthermore, it maintains stability in crosswinds above 35 km/h, minimizing steering drift and slip.

This rim utilizes aerospace-grade progressive layup technology to continuously enhance its rigidity, increasing lateral stiffness by 18%, thereby reducing power loss and enhancing precise cornering control. They also offer 30% greater impact resistance than traditional rims and have passed 100 dynamic load cycle tests, ensuring structural stability and reliability under intense riding conditions. Designed specifically for modern road systems, they are tubeless-ready and compatible with both tubeless tires and inner tubes, supporting 11-12 speed cassettes (with an optional XDR freehub body), and feature a durable braking edge that ensures thermal stability and durability under frequent downhill braking.

Product Features and Advantages

Widebody Aerodynamics:

The rim design incorporates aerodynamics to optimize the bike's performance, stability, handling, and energy conversion. The 26mm rim width, optimized through wind tunnel testing, pairs well with modern tires (23-42c). Its "airfoil" profile significantly reduces drag, minimizing rider energy loss and maintaining stability in crosswinds, enhancing high-speed efficiency and handling confidence.

Lightweight, Highly Stiff, and Instantly Responsive:

Weighing a mere 475±15g, the rim utilizes KOIBIKE's aerospace-grade carbon fiber layup technology to increase lateral and longitudinal rigidity, resulting in a lightweight yet highly rigid rim that enhances riding performance and handling.

Enhanced Comfort and Grip:

The 19mm internal width and 26mm external width meet modern tire preferences. Wider tires are perceived as providing more ground contact, leading to greater stability and security. Low tire pressures also provide excellent shock absorption, significantly improving comfort, traction, and handling on rough, gravel, and light gravel surfaces.

Strict Quality Control:

KOBIKE do 100% tire pressure(150 PSI), flatness(＜0.2mm) and roundness(＜0.2mm) inspections before shipping, also offering 2 years warranty for our carbon rims.

Product Structure

KOIBIKE Ultra-Light Carbon Rims | 375±15g High-Performance Road/Enduro/Gravel Universal Platform

KOIBIKE Ultra-Light Carbon Rims weigh just 475±15g per rim, support tire widths from 23C–42C, and are fully compatible with both tubeless and clincher tires, providing a highly flexible system solution for modern road, enduro, and gravel riding. The lightweight design significantly reduces rotational inertia, improving acceleration responsiveness and climbing efficiency while also ensuring dynamic stability in complex road conditions.

Reinforced Sidewall Structure | Multi-Directional Cross-Lamination Technology

The rim utilizes a multi-directional cross-laminated construction process at 50°, 90°, and 70° angles to create a three-dimensional stress-bearing network. This structure not only enhances lateral stiffness and impact resistance, but also effectively suppresses tire bed deformation under high pressure (up to 90 psi), ensuring structural consistency during extended descents, gravel runs, and enduro stages. It is compatible with both rim and disc brake systems, meeting the compatibility requirements of different vehicle platforms.

High-Tension Spoke System | Structural Anchorage Reliability

The spoke cap hole area features a carbon fiber-reinforced ring reinforcement structure, proven to withstand a 300 kg spoke pull-out force, ensuring circumferential integrity even during high-tension wheelbuilding. This design improves wheel tension retention over long-term use, reduces maintenance, and is suitable for high-intensity racing and harsh terrain applications.

Versatile Performance Platform | Seamless Transition from Road to Gravel

The combination of an extremely lightweight 375g rim and wide tire compatibility enables this rim to be used in a variety of scenarios: efficient cruising on smooth roads, enhanced endurance in endurance races, and improved traction, riding comfort, and reduced vibration on gravel roads. The lightweight yet strong design philosophy is consistently applied throughout, balancing acceleration agility with long-distance durability.

Application Areas

Long-Distance Road Riding

For sustained rides spanning hundreds of kilometers, the lightweight construction reduces wheel rotational load and improves pedaling response. Tubeless compatibility allows for lower tire pressures, effectively absorbing road vibrations and reducing fatigue in the hands, hips, and lower back. The 50mm rim depth maintains excellent cruising efficiency on flat roads without adding excessive inertia on climbs, allowing riders to maintain a steady pace during multi-day rides.

Endurance Racing and Gran Fondo

For endurance races with frequent ups and downs, complex terrain, and long durations, this rim demonstrates its comprehensive adaptability: aerodynamic performance helps conserve energy on high-speed sections, crosswind stability ensures confidence in cornering and descents, and wide tire compatibility handles gravel, wet, or broken roads. The combination of lightness and stiffness keeps riders in control during sprints, breakaway accelerations, and continuous climbs.

All-Weather Road Use

The 50mm rim depth provides stability in crosswinds and is resistant to gusts, enhancing safety and confidence when riding in the rain, along the coast, or on open terrain. Its robust construction and durability make it ideal for high-intensity training, repeated climbs, or quick urban commutes, balancing performance with everyday practicality.

Performance Upgrade for Stock Bikes

For road or endurance bikes equipped with stock aluminum rims, replacing these carbon rims significantly improves overall responsiveness, cruising efficiency, and ride quality. It's a cost-effective option for achieving a quantum leap in performance without replacing the entire bike.

Technical Parameters

Customized Weaves & Finishes:

Customized Laser Engraving Brake Track:

Customized Holes:

Factory Overview

Areas: 2500 ㎡

People: 100

Histroy: 12 years

Capacity: 10000 pcs/month for carbon rims/wheels, 50000 pcs/month for carbon spokes, cranks and other bicycle parts.

Weight Check:

Clean burrs ＆ residues

Rim Diameters Check:

Cleaning & Packing

R50X26TL-UL Product Show