Carbon Fiber Sporting Goods
700c Carbon Road Rim 40mm – Tubeless, 28mm Wide, Asymmetric or Symmetric, 345–425g
700c Carbon Road Rim 40mm – Tubeless, 28mm Wide, Asymmetric or Symmetric, 345–425g
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700c Tubeless Carbon Road Rim – 40mm Profile, 28mm Wide
This 700c carbon clincher/tubeless rim delivers a 40mm aerodynamic profile with a 28mm external width and choice of 21mm or 23mm internal width. Available in four weight tiers — from 425g (standard) down to 345g (extreme light) — it suits road racers, gran fondo riders, and competitive wheelset builders who need measurable weight savings without sacrificing structural integrity.
Key Specifications
| Parameter | Value |
|---|---|
| Diameter | 700c (ISO 622mm) |
| Rim Profile | 40mm |
| Outer Width | 28mm |
| Inner Width | 21mm or 23mm |
| ERD | 559mm |
| Rim Shape | U-shape (tubeless-ready) |
| Weight Options | 425±15g / 390±10g / 365±10g / 345±10g |
| Forward Compressive Strength | >300 kg |
| Lateral Torsion | >50 kg |
| Spoke Hole Tension | >280 kg |
| Dynamic Equilibrium | <3g imbalance |
| Flatness | <0.15mm |
| Roundness | <0.3mm |
| Valve Hole Diameter | 6.5mm (customizable) |
| Spoke Hole Diameter | 4.5mm (customizable) |
| Assembly Hole Diameter | 7.5mm (customizable) |
| Tire Pressure Range | 100–125 psi |
| Max Rider Weight | 120 kg |
| Nipple Angle (Asymmetric) | Front: 7° / Rear: 5°×7° (customizable) |
Asymmetric vs. Symmetric: Which Should You Choose?
Asymmetric rims offset the spoke bed laterally to equalize drive-side and non-drive-side spoke tension on the rear wheel. This reduces stress concentration at the flange and improves wheel stiffness under pedaling load — recommended for rear wheels on derailleur drivetrains. Symmetric rims use a centered spoke bed and are standard for front wheels or single-speed builds. Both configurations are available in all four weight tiers.
21mm vs. 23mm Inner Width: Practical Difference
A 23mm inner width optimally supports 28c–32c tires, reducing tire sidewall pinch and improving cornering stability at 100–125 psi. A 21mm inner width suits 25c–28c tires and is the more common choice for pure road racing builds. The wider 23mm channel also lowers rolling resistance by allowing a rounder tire profile.
Use-Case Fit
- Climbing & hill stages: 345g or 365g tier reduces rotational mass; 40mm profile keeps aerodynamic benefit without the crosswind penalty of 50mm+ rims.
- Flat road racing & criteriums: 40mm depth provides measurable aerodynamic advantage over shallow rims at speeds above 35 km/h, while remaining manageable in crosswinds.
- Gran fondo / endurance: 390g or 425g tiers offer greater durability; tubeless setup at 100 psi reduces road vibration and puncture risk.
- Custom wheelset builds: Spoke hole diameter (4.5mm), valve hole (6.5mm), and nipple angle are all customizable on request.
Tradeoffs to Know
The 345g extreme-light tier prioritizes weight reduction; riders above 90 kg or those on rough road surfaces should consider the 390g or 425g tier for improved impact resistance. Spoke tension ceiling of >280 kg per hole is consistent across all weight variants. Maximum rider weight is 120 kg across all configurations.
Frequently Asked Questions
- Q: Are these rims compatible with standard road tubeless valves?
- A: Yes. The 6.5mm valve hole accepts standard 60mm and 80mm tubeless valve stems. Custom valve hole diameters are available on request.
- Q: What tire width range works best with the 23mm inner width version?
- A: 28c to 32c tires are optimal. At 25c, a 23mm inner width still functions but offers less of a rounding benefit compared to a 21mm channel.
- Q: Is the 40mm profile a good all-rounder for both climbing and flat racing?
- A: For most road racers, yes. The 40mm depth offers aerodynamic gains at racing speeds while keeping crosswind handling predictable — a recognized tradeoff point versus 50mm or 60mm profiles.
- Q: What is the warranty on these rims?
- A: A three-year manufacturer warranty is included. Coverage applies to manufacturing defects in carbon layup and spoke hole integrity.
- Q: Can spoke count and drillings be customized?
- A: Yes. Spoke hole count, diameter (standard 4.5mm), and nipple angle are all available as custom configurations. Contact the manufacturer directly for batch specifications.
