The FB25X65-26ER is an innovative product born from this robust manufacturing system. It combines the lightweight, rigid, and aerodynamically optimized pursuits of road carbon rims with the demanding requirements of extra-wide support, impact resistance, and low-temperature stability required of snow rims. Utilizing aviation-grade Toray T700/T800 carbon fiber, structural stress distribution is optimized through Finite Element Analysis (FEA) to ensure superior performance even in extreme -30°C conditions. Whether used for branded OEM applications, race equipment upgrades, or high-end custom frames, the FB25X65-26ER demonstrates exceptional engineering value and market competitiveness.

Product Features and Advantages

Extra-wide 65mm external width: 

Provides strong sidewall support for 4.0–5.0-inch tires, significantly improving flotation and handling stability on snow, sand, and muddy roads.

A breakthrough in carbon fiber lightweighting: weighing only 600g (±15g) per rim, it's over 30% lighter than traditional aluminum rims, significantly improving riding efficiency and overall vehicle responsiveness.

Optimized Braking: 

Adapted for snow-specific disc brake pads, increasing the braking contact area. The surface has been tested for low-temperature friction coefficient, ensuring stable braking even on ice and snow, reducing stopping distance by approximately 20% compared to standard rims.

Superior Grip Design: 

Increases contact area with the snow; dense, fine grooves effectively break through the ice and embed it into the snow, providing strong grip.

Various High-End Paint Options: 

Available in UD, marble, 12K straight, and 12K twill finishes, meeting brand differentiation and customization needs.

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

Rim Height and Profile: 

The 25mm low-profile design prioritizes lateral stiffness and stability over aerodynamics, ideal for the low-speed, high-torque characteristics of snow cycling.

External Width and Tubeless Ready Monocoque Construction: 65mm ultra-wide outer diameter, using a vacuum-molded monocoque process, and seamless construction enhances airtightness and overall strength.

Tire Size Recommendation: 

Suitable for 26-inch wheels, 4.0–5.0-inch tires are recommended, with tire pressures as low as 5–15 psi for optimal contact patch and cushioning.

Rim Structure and Rigidity: 

Utilizing a double-layer carbon fiber reinforcement layer, with a focus on strengthening the tire bed and spoke hole areas, lateral rigidity is approximately 40% higher than similar-sized aluminum rims, effectively reducing pedaling deflection.

Brake Track Design: 

Optimized specifically for disc brake systems, the absence of a brake track reduces unnecessary weight while also preventing brake fade associated with carbon brake tracks in cold temperatures.

Aerodynamic Considerations: 

While not a high-speed aero wheel, the wide profile still helps guide airflow at low speeds, reducing local turbulence and improving overall vehicle stability.

Application Areas

Application areas for the FB25X65-26ER carbon bicycle rim:

Arctic & Snow Cycling: 

Designed for winter polar expeditions and fat bike racing, it provides excellent flotation and traction in deep snow.

Desert & Beach Crossing: 

The ultra-wide 65mm rim, when combined with low tire pressure, allows for a "water-skimming" ride on soft sand, making it widely used in desert expeditions and coastal cycling.

Gravel & Bikepacking: 

Suitable for extreme mixed terrain, such as frozen soil, gravel, and mud, making it the ultimate choice for long-distance adventure cyclists.

Brand OEM/ODM Cooperation: Suitable for private label production or custom development for high-end domestic and international bicycle brands, tuners, and racing teams. KOIBIKE provides full-cycle support from design to delivery.

Technical Parameters

Customized Weaves & Finishes:

Customized Laser Engraving Brake Track:

Customized Holes:

Weight Check:

Clean burrs ＆ residues

Rim Diameters Check:

Cleaning & Packing

FB25X65-26ER Product Show