Ultralight Carbon Gravel Bike Rims 700c | 34mm Wide, UV-Shape, 35mm & 40mm | Disc Brake | Bola

Discover the Benefits of Ultralight 700c Carbon Gravel Rims

Bola's 700c carbon gravel rims deliver verified disc-brake performance in three weight classes — Normal (460g), Superlight (410g), and Ultralight (360g per rim) — with a 34mm outer / 25mm inner U-shape profile optimised for tubeless gravel tyre compatibility from 28c to 50c. Available in 35mm and 40mm heights to suit either all-day endurance riding or aerodynamic efficiency.

Who These Rims Are Designed For

• Competitive gravel and cyclocross teams requiring sub-400g disc-specific rims without sacrificing structural integrity
• Small and medium cycling brands seeking OEM/white-label rims with consistent, verifiable quality (three-year warranty)
• Endurance cyclists running wide tubeless setups who need a 25mm inner width for reduced rolling resistance and improved tyre volume

Rim Profile Options: 35mm vs. 40mm

Full Technical Specifications

• Rim Shape: U-shape (wider internal channel vs. V-shape; optimised for gravel tyre profiles)
• Outer Width: 34mm (variant: 31mm available)
• Inner Width: 25mm (tubeless-ready)
• Weight per Rim: Normal 460±15g | Superlight 410±10g | Ultralight 360±10g
• Forward Compressive Strength: >300kg
• Lateral Torsion: >50kg
• Spoke Hole Tension: >280kg
• Dynamic Equilibrium: <3g imbalance
• Flatness Tolerance: <0.15mm
• Roundness Tolerance: <0.3mm
• Assembly Hole Diameter: 7.5mm (customisable)
• Spoke Hole Diameter: 4.5mm (customisable)
• Nipple Direction: Front 7°, Rear 5° & 7° (customisable)
• Tyre Pressure Range: 100–125 psi
• Max Rider Weight: 120kg
• Brake Compatibility: Disc brake only

Why U-Shape Over V-Shape for Gravel?

The U-shape profile maintains a consistent internal channel width of 25mm across the full bead-seat area. Compared to a V-shape rim of equivalent height, the U-profile reduces tyre deformation under cornering loads and supports a broader tyre volume range (typically 32c–50c), which is critical for mixed-surface gravel riding. V-shape rims of similar height typically offer 2–4mm narrower internal widths, increasing tyre sidewall tension and limiting tubeless bead retention reliability on rough terrain.

Weight Class Comparison

Note: The 50g reduction from Normal to Ultralight (per rim) translates to 100g savings across a paired wheelset. Ultralight rims are recommended for riders under 100kg on non-technical terrain to maintain the rated structural tolerances above.

Customisation & OEM Services

All hole diameters (assembly, valve, spoke) are available in custom dimensions. Nipple angle, drilling pattern, and branding options are offered for cycling brands and professional teams. Minimum order quantities and lead times are available on request. Three-year warranty included on all production runs.

Frequently Asked Questions

Q: Are these rims tubeless-compatible?

A: Yes. The 25mm inner width and U-shape profile are engineered for tubeless tyre fitment. A tubeless-ready rim tape and valve are required and sold separately.

Q: Should I choose 35mm or 40mm height for gravel riding?

A: 35mm is recommended for technical or mixed-surface gravel where vertical compliance and handling agility are priorities. The 40mm profile provides measurable aerodynamic advantage on faster, smoother gravel or mixed-road segments, with minimal additional weight penalty at this rim width.

Q: What is the weight difference between Superlight and Ultralight versions?

A: The Superlight weighs 410±10g per rim; the Ultralight weighs 360±10g per rim — a nominal 50g difference per rim, or approximately 100g for a full wheelset build.

Q: What tyre widths are compatible with the 25mm inner width?

A: A 25mm inner width is compatible with tyres from approximately 28c to 50c. ETRTO guidelines recommend a minimum tyre width of 28mm for a 25mm internal rim width to maintain safe bead retention.

Q: Can these rims be used with rim brake systems?

A: No. These rims are designed exclusively for disc brake drivetrains. There is no braking surface machined into the rim sidewall.

Precision Engineering for Peak Performance

The ultralight 700c carbon gravel rims are crafted to deliver exceptional performance on diverse terrains. Featuring a 34mm wide profile and UV-shaped design, these rims offer enhanced aerodynamic efficiency and improved tire support. Their lightweight construction reduces rotational mass, helping riders accelerate quicker and climb more efficiently. These rims are optimized for disc brake setups, ensuring consistent stopping power and safety regardless of trail conditions. Whether you're competing or trail riding, these carbon rims enhance responsiveness and stability, making every ride smoother and more enjoyable.

Durability and Lightweight Design Combined

Built from high-quality carbon fiber, these gravel rims balance durability with an ultralight weight. The 35mm and 40mm depth options provide versatility for different riding styles and terrain challenges. The carbon material resists corrosion and fatigue, offering long-lasting reliability even under demanding conditions. The wide 34mm internal width enhances tire volume capacity, improving traction and comfort on rough roads. This makes the ultralight 700c carbon gravel rims a smart investment for serious cyclists seeking both speed and endurance without sacrificing strength.

Compatibility and Versatility for Every Gravel Rider

Designed specifically for disc brake systems, these rims ensure ease of setup and maintenance on modern gravel bikes. Their 700c diameter suits a broad range of tires, allowing riders to customize their setup based on preferred terrain or riding style. The UV-shaped rim profile improves aerodynamics and helps protect against impacts, making them suitable for aggressive off-road use. With Bola’s focus on quality and innovation, these ultralight carbon gravel rims deliver an ideal blend of performance, durability, and style for riders aiming to elevate their gravel biking experience.