700c Carbon Road Rim 50mm Profile 28mm Wide – Tubeless Hook or Hookless, 370–470g | Bola

Bola 700c Carbon Tubeless Road Rim – 50mm Profile, 28mm Outer Width

A 700c full-carbon clincher/tubeless rim with a 50mm aerodynamic profile and 28mm outer width (21mm or 23mm inner). Available in four weight tiers from 470 g down to 370 g per rim. Compatible with both hooked and hookless tubeless setups. Max rider weight: 120 kg. Three-year manufacturer warranty.

Weight Tiers

Trade-off note: Extreme Light rims (370 ± 10 g) offer the lowest rotational mass but carry a tighter tolerance band. Riders prioritising durability for training volume should consider the Standard or Super Light tier.

Full Technical Specifications

• Rim Shape: U-shape
• Rim Height: 50 mm
• Rim Outer Width: 28 mm
• Rim Inner Width: 21 mm or 23 mm (specify at order)
• ERD: 538 mm
• Compatibility: Hook-bead or Hookless tubeless (specify at order)
• Assembly Hole Diameter: 7.5 mm (customisable)
• Valve Hole Diameter: 6.5 mm (customisable)
• Spoke Hole Diameter: 4.5 mm (customisable)
• Nipple Direction: Front 7°; Rear 5° or 7° (customisable)
• Min / Max Tyre Pressure: 100 / 125 psi
• Max Rider Weight: 120 kg

Structural Strength Data

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

Hook vs Hookless: Which Should You Choose?

Hooked (hook-bead) rims retain compatibility with a wider range of clincher and tubeless tyres, including older tyre models. They are the safer choice if you frequently swap tyre brands.

Hookless rims allow a more uniform carbon layup, which can improve impact resistance and marginal weight savings. However, hookless requires tyres that are explicitly rated for hookless use — verify compatibility with your tyre manufacturer before ordering. Max tyre pressure on hookless setups is typically limited to 72.5 psi (5 bar) per industry guidelines; confirm with your tyre brand.

28mm Wide Rim vs 25mm: Performance Considerations

A 28mm outer / 21–23mm inner rim allows modern 25c–32c tyres to form a rounder cross-section, reducing rolling resistance and improving cornering stability. Wind-tunnel data from multiple rim manufacturers shows aerodynamic drag parity or improvement versus narrower rims when paired with a tyre 5–8 mm wider than the rim's inner width. The 28mm platform is well-suited to riders running 28c or 30c road tyres.

Frequently Asked Questions

Is this rim compatible with standard road bike hubs?

Yes. The 4.5 mm spoke holes and 538 mm ERD are compatible with standard J-bend and straight-pull spokes. Nipple angle options (5° or 7° rear) accommodate both symmetric and asymmetric lacing patterns.

What tyre width is recommended for the 23mm inner width option?

For a 23 mm inner width, a 28c–32c tyre is recommended for optimal casing shape and rolling resistance. A 25c tyre will also mount but produces a narrower casing profile.

What does the three-year warranty cover?

The warranty covers manufacturing defects in the carbon layup and spoke hole integrity under normal riding conditions. Crash damage and modifications are excluded. Contact Bola directly for warranty claims.

Can I order custom spoke hole counts or drilling patterns?

Yes. Hole diameter, valve hole size, and nipple direction are customisable at order. Contact the manufacturer to specify requirements.

What is the minimum tyre pressure for tubeless use?

The manufacturer specifies a minimum of 100 psi and a maximum of 125 psi. For hookless variants, observe your tyre manufacturer's hookless pressure limit, which is typically lower.