700c 40mm Carbon Road Rim – 30mm or 34mm Wide, 23mm Inner Width, Tubeless Ready | Bola

700c 40mm Carbon Road Rim – 30mm or 34mm Outer Width, 23mm Inner Width

The Bola 40mm carbon road rim delivers a verified weight range of 380–430g per rim across three build grades, a 23mm inner width for compatibility with 25–32mm road and gravel tires, and a UV-cured resin finish. Available in 30mm and 34mm outer widths, this rim is designed for competitive road racing, endurance cycling, and OEM partnerships with small to medium cycling brands and professional teams.

Key Specifications

Weight Grade Comparison

Structural Strength Testing

• Forward Compressive Strength: >300 kg
• Lateral Torsion Resistance: >50 kg
• Spoke Hole Tension: >280 kg
• Dynamic Equilibrium (imbalance): <3g
• Flatness tolerance: <0.15mm
• Roundness tolerance: <0.3mm

30mm vs. 34mm Outer Width – Which Should You Choose?

The 34mm outer width provides a wider tire-to-rim interface, improving aerodynamic performance when paired with 28–32mm tires by reducing the turbulent 'light bulb' effect at the tire shoulder. The 30mm outer width suits riders prioritizing lower rotational weight and compatibility with narrower 25–28mm tire setups. Both widths share the same 23mm inner width and 40mm profile, so wheel stiffness and spoke tension behavior remain comparable across both configurations.

Note: The ultralight grade (380 ±10g) achieves its weight reduction through selective carbon layup optimization. Riders exceeding 90 kg or competing on rough road surfaces may prefer the standard or superlight grade for additional fatigue resistance.

Customization & OEM Availability

• Spoke hole count: customizable per order
• Hole diameters (valve, spoke, assembly): customizable
• Nipple angle: front 7°, rear 5° or 7°, or custom specification
• Private label and OEM branding available for cycling brands and professional teams
• Three-year warranty included on all grades

Compatibility

• Tire type: Clincher, tubeless-ready (with compatible tape and valves)
• Recommended tire width: 25–32mm (700c)
• Drivetrain compatibility: Compatible with all standard road groupsets via cassette body selection at wheel build stage
• Brake type: Disc brake only (no braking surface machined)

Frequently Asked Questions

Are these carbon rims tubeless compatible?

Yes. The 23mm inner width and U/UV rim shape are tubeless-ready when used with appropriate rim tape (recommend 25mm width) and tubeless valve stems with a 6.5mm hole diameter. Maximum tire pressure is 125 psi.

What is the difference between the superlight and ultralight grades?

The superlight grade (400 ±10g) uses a balanced carbon layup suitable for most competitive road and endurance applications. The ultralight grade (380 ±10g) reduces weight by approximately 20g per rim through a refined layup schedule. Both pass the same structural tests; however, the ultralight grade is recommended for riders under 85 kg on smooth road surfaces.

Is a 34mm wide rim better than 30mm for road aerodynamics?

For tires 28mm and wider, the 34mm outer width reduces the tire-rim shoulder gap, which wind tunnel data from rim manufacturers consistently shows improves aerodynamic efficiency above 35 km/h. For 25mm tires, the 30mm outer width maintains a better aerodynamic profile ratio.

What tire pressure should I use with these rims?

The rated range is 100–125 psi. For tubeless setups with 28mm tires, most riders perform well at 70–90 psi, though the structural rating remains 100 psi minimum for clincher use. Always verify with your tire manufacturer's pressure guidelines.

Can I order custom spoke hole counts or private-label branding?

Yes. Spoke hole count, hole diameters, nipple angles, and OEM/private-label branding are all available as custom configurations. Contact us with your technical drawing or specification sheet for a production quote.