Carbon Fiber Sporting Goods
Asymmetric Carbon 29er MTB Rim – 23mm High, 26mm Inner Width, XC & Trail, 300–370g (Bola)
Asymmetric Carbon 29er MTB Rim – 23mm High, 26mm Inner Width, XC & Trail, 300–370g (Bola)
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🚚 预计发货：15天内
Bola Asymmetric Carbon 29er MTB Rim — 23mm Profile, 26mm Inner Width
This asymmetric carbon rim delivers a 23mm profile height and 26mm inner width in a 29-inch format, purpose-built for cross-country racing and all-mountain trail riding. Available in three weight tiers: Normal (370 ±15g), Superlight (325 ±10g), and Ultralight (300 ±10g) per rim.
Key Specifications
| Parameter | Value |
|---|---|
| Rim Size | 29er (ERD: 589mm) |
| Rim Profile Height | 23mm |
| Outer Width | 32mm |
| Inner Width | 26mm |
| Rim Shape | U-shape (asymmetric) |
| Weight — Normal | 370 ±15g |
| Weight — Superlight | 325 ±10g |
| Weight — Ultralight | 300 ±10g |
| Forward Compressive Strength | >300kg |
| Lateral Torsion Resistance | >50kg |
| Spoke Hole Tension Strength | >280kg |
| Dynamic Equilibrium | <3g |
| Flatness Tolerance | <0.15mm |
| Roundness Tolerance | <0.3mm |
| Nipple Angle | Left 5°, Right 7° (or custom) |
| Valve Hole Diameter | 6.5mm (or custom) |
| Spoke Hole Diameter | 4.5mm (or custom) |
| Assembly Hole Diameter | 7.5mm (or custom) |
| Tire Pressure Range | 45–65 psi |
| Max Rider Weight | 100kg |
Design Rationale: Why Asymmetric?
The asymmetric spoke bed offsets the spoke holes to equalise tension between drive-side and non-drive-side spokes. This reduces the spoke tension differential — a known cause of wheel fatigue and spoke breakage — resulting in a more durable, more evenly loaded wheel structure. The 26mm inner width accommodates 2.2–2.6-inch tubeless tires with an optimal casing spread for grip and rolling efficiency on XC and trail terrain.
Weight Tier Comparison
| Tier | Weight | Best For | Tradeoff |
|---|---|---|---|
| Normal | 370 ±15g | Enduro, aggressive trail, heavier riders | Heavier, but maximises structural margin |
| Superlight | 325 ±10g | All-mountain, trail racing | Balanced weight-to-durability ratio |
| Ultralight | 300 ±10g | XC racing, weight-optimised builds | Thinner layup; suits riders under 75kg and smoother XC trails |
Note: The Ultralight variant is optimised for competitive XC use. Riders above 80kg or riding highly technical, rock-heavy terrain are advised to select the Normal or Superlight tier to maintain structural safety margins.
Customisation Options
- Spoke hole count: configurable on request
- Valve hole diameter: 6.5mm standard or custom
- Spoke hole diameter: 4.5mm standard or custom
- Assembly hole diameter: 7.5mm standard or custom
- Nipple angle: Left 5° / Right 7° standard or custom
Frequently Asked Questions
- What tire widths are compatible with this rim's 26mm inner width?
- A 26mm inner width is ETRTO-compatible with 2.2–2.6-inch (56–66mm) mountain bike tires. It provides an optimal casing spread for both XC race and trail-oriented tires at 45–65 psi tubeless pressures.
- What is the difference between the Ultralight and Normal weight versions?
- The Ultralight (300 ±10g) uses a thinner carbon layup to reduce weight for XC racing. The Normal (370 ±15g) uses a thicker layup for greater impact resistance. Both share identical spoke tension strength (>280kg) and forward compressive strength (>300kg).
- Are asymmetric rims worth it for 29er XC and trail builds?
- Yes. Asymmetric rims equalise drive-side and non-drive-side spoke tension, reducing fatigue-related spoke failure — a measurable advantage in 29er builds where the larger wheel diameter increases spoke tension variance.
- Is this rim tubeless-ready?
- The U-shape profile and 6.5mm valve hole are compatible with tubeless setups. A tubeless rim tape and valve are required and not included.
- What is the maximum rider weight?
- The rated maximum rider weight is 100kg across all weight tiers. Riders approaching this limit are recommended to select the Normal weight variant for maximum structural margin.
- Does Bola offer a warranty on these rims?
- Yes. Bola provides a three-year warranty covering manufacturing defects on carbon rims.
