The design philosophy of the KOIBIKE EM-MA28X38HL-29ER-SL shifts from "peak strength" to "fatigue tolerance cycle management." Rather than pursuing extreme rigidity, it builds a dynamic system that continuously absorbs, disperses, and releases mechanical energy. The 38mm outer width is the core of this philosophy: it not only supports tires 2.1–2.6 inches wide, but more importantly, it extends the tire's deformation path, dissipating impact energy gradually over a wider radius of the tire carcass, reducing localized stress concentration. Combined with a low tire pressure window of 18–30 psi, this creates a "soft contact, slow rebound" cushioning mechanism, significantly reducing neuromuscular stress on riders during long, technical sections.The rims utilize a Toray T700/T800 hybrid carbon fiber, with a layup optimized using an energy-dissipating topology algorithm. This reinforces tensile strength in the spoke anchor area and incorporates a high-tenacity fabric at the rim's top, creating a synergistic "rigid anchor point + elastic buffer zone" structure. This achieves high durability despite its lightweight of 490g.

Product Features and Advantages

38mm Extra-Wide Outer Diameter: 

Extends the tire's deflection path, improving contact patch continuity and impact absorption.

28mm Depth:

Optimizes stiffness and lightweight, ideal for the high-load conditions of enduro racing.

340g Controlled Mass: 

Lightweight design reduces unsprung mass, improving the wheel's handling on challenging terrain.

3mm Offset Spoke Holes: 

Optimizes left-right tension distribution, enhancing the wheel's structural stability under asymmetric impacts.

18–30psi Wide Pressure Window: 

Compatible with modern low-pressure strategies, improving grip and riding comfort.

2.1–2.6-inch Wide Compatibility: 

Covers mainstream all-mountain and enduro tire sizes, enhancing system flexibility.

Four Design Options (UD/Marble/12K/12K Twill): 

Meet brand identity and end-user needs.

Tubeless Compatible: 

Supports self-sealing for enhanced reliability and puncture resistance during long-distance riding.

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

Energy Dissipation Topological Layup: 

Based on impact path simulation, the carbon fabric orientation and ply distribution are optimized to achieve stress dispersion.

External Width Functional Definition: 

The 38mm width, verified by dynamic ground contact simulation, creates a continuous support arc for 2.1-2.6-inch tires.

Offset Aperture Design: 

A 3mm offset minimizes tension differences, improving the wheelset's structural consistency during jumps and rock ledges.

Vacuum Seal Interface: 

An integrally molded bead seat ensures a highly reliable seal and supports low tire pressure operation.

Spoke System Compatibility: 

Supports 28H/32H lacing, with a cross-3 braid recommended. Carbon fiber-reinforced eyelets improve tension retention.

Material & Process: 

High-modulus Toray carbon fabric, vacuum-bagging, and high-temperature curing ensure a dense structure and uniform resin distribution.

Appearance: 

Available in four finishes: UD matte, marble, 12K plain, and 12K twill to meet diverse aesthetic needs.

Application Areas

Application areas for the EN-MA28X38HL-29ER-SL carbon bicycle rim:

Enduro Energy Management Platform: 

Continuously dissipates impact energy and minimizes handling degradation during multi-hour descents and technical sections.

All-Mountain High-Intensity Response System: 

Demonstrates the comprehensive impact resistance of the widebody + offset design on steep slopes, jumps, and rocky terrain.

The Reliable Choice of Racing Teams: 

Validated through thousands of impact cycles, it's suitable for high-intensity training and multi-day racing environments.

OEM/ODM High-End Customization: 

KOIBIKE offers full-process customization services, from structure and materials to exterior design, to help brands create their own exclusive enduro product lines.

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

EN-MA28X38HL-29ER-SL Product Show