• BOLA 88mm Aero Carbon Rim 700C – Hooked Tubeless, 27mm/20mm, TT & Triathlon（副本）
  • BOLA 88mm Aero Carbon Rim 700C – Hooked Tubeless, 27mm/20mm, TT & Triathlon（副本）
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Bola 700C 40mm Carbon Tubeless Road Rim | 28mm Wide

Bola 700C 40mm Carbon Tubeless Road Rim | 28mm Wide

$310.00 USD
$350.00 USD $310.00 USD
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The Bola 700C 40mm U-shape carbon tubeless rim - a 28mm-wide disc-brake aero rim for climbing, fast group rides and all-round road builds.

Fast group rides, long training days, decisive climbs - the Bola 40mm U-shape rim brings a carefully engineered balance of aero and compliance. Forty millimetres of carbon, 28mm wide, sold rim-only.

Buying Guide.

Weight tier - Extreme Light ~345g: the climber's pick - lightest end, calm in the gusts.

Weight tier - Ultralight ~365g: the balanced middle - light enough to race, tough enough to train.

Weight tier - Superlight ~390g: the steady build - impact margin for windy training days.

Weight tier - Standard ~425g: the durable daily choice for heavier riders and rough roads.

Max rider weight: rated to 105kg - check rider + gear before ordering.

Same-depth series: the 40mm road/gravel rim is the wide-outer version; the 40mm asymmetric tubeless balances disc spoke tension.

Adjacent depth: the 35mm U-shape climbs better; the 45mm U-shape adds aero.

Target Audience & Usage Notes.

Target audience.: Climbers, gran fondo riders and those in windy terrain.

Rim-only.

Hookless requires ETRTO-certified tyres at 72-87 psi; hooked supports up to 110 psi.

Respect 105kg.

Not for flat TT maximum speed.

The Ride That Awaits.

Build it around a disc road hub, seat a 28-32c tubeless, and the 40mm U-profile threads the needle: fast enough for the flat, light enough for the climbs, calm in every gust. The aero-stability compromise, perfected for your kind of road. Free shipping, a 3-year rim warranty and crash-replacement discount.

Specifications
Size: 700c
Material: Genius Toray carbon fiber
Rim Depth: 40mm
Bead Type: Hooked
Inner Width: 21mm hooked / 23mm hookless
Outer Width: 28mm
ERD (Effective Rim Diameter): 558mm
Weight Tier: Extreme Light 345g / Ultralight 365g / Superlight 390g / Standard 425g (+/-10-15g)
Trade-offs & Considerations
Aero vs Crosswind: The 40mm depth saves about 3.0W versus a 30mm rim at 40km/h; at 10° yaw the shallower 40mm section and 28mm outer width keep steering calm on exposed roads, giving up some aero gain compared with a 50mm rim.
Weight vs Stiffness: The Extreme Light tier (345g) saves about 80g versus the Standard tier (425g) at the same 40mm depth (±5g); lateral stiffness holds within 3% across tiers, so the lightest layup keeps the same rim structure.
Tire-Type Trade-off: The hooked 21mm bead accepts clincher and tubeless tyres from about 25c to 38c up to 110 psi; the hookless 23mm bed runs 27–38c at 72–87 psi with ETRTO-certified tyres, trading a narrower pressure range for a more voluminous, lower-rolling bed.
Sourcing & Delivery Trade-off: Stock drilling ships in 1–3 business days at $310; custom spoke-hole count or decals add 7–15 business days and roughly a $40–80 premium.
Performance Test Data
Fatigue Test: 750,000 cycles @640N (ISO 4210-7 Annex A, informative only)
Impact Resistance: >40J (ISO 4210-7 reference)
Flatness: <0.25mm (internal QC)
Roundness: <0.3mm (internal QC)
Max Spoke Tension: >300kg (internal QC)
Ultimate Strength: >100kg (internal QC)
Dynamic Equilibrium: <3g (internal QC)
Radial Stiffness: 62–74 N/mm (internal lab)
Lateral Stiffness: 8–13 N/mm
Max System Weight: 105kg
Recommended Use Cases
Road Racing Builds: 2026 peloton standard is 28-30mm tubeless on wide rims (TdF 2026 avg ≈30mm); 40mm section suits 40+ km/h racing.
Gran Fondo / Endurance: Modern 2026 frames (Propel, SuperSix, S5) design around 30-32mm clearance; 21mm inner bed pairs 25-32mm tubeless per ETRTO 2026 guidance.
Wheel Building: Custom road builds with disc or rim hubs; UD carbon layup options for weight-conscious or durable builds.
Weight Tier Selection: Offered in weight tiers (105kg); lighter for climbing, heavier for training and impact margin.
Compatibility
Frame: 700C road frames with 100mm front / 130-142mm rear disc spacing
Tire Type: Tubeless-ready clincher
Tire Width: 25-35c
Valve: Presta
Brake: Disc only - center-lock or 6-bolt rotor hub
How It Compares
FAQ
What tyre widths fit this rim?
With a 21mm hooked (23mm hookless) internal width, run 25–38c clincher or tubeless tyres; 28c is the road aero sweet spot.
What is the ERD for spoke length calculations?
558mm. Use this Effective Rim Diameter when calculating spoke lengths for custom 20/20 builds.
Hooked or hookless — which should I choose?
The hooked 21mm bed runs 25–38c up to 110 psi and works with nearly all tyres; the hookless 23mm bed is slightly more voluminous but requires ETRTO hookless-certified tyres at 72–87 psi.
Which weight tiers are available?
Extreme Light 345g, Ultralight 365g, Superlight 390g and Standard 425g (±10–15g) are selectable for climbing or training builds.
Is this rim for disc brakes only?
Yes. It has no rim-brake braking surface and is built for disc-brake road and endurance setups.
Warranty & Shipping
Warranty Period: 3 years
Crash Replacement: 30% discount on replacement parts
Processing Time: 1–3 business days (standard stock); 7–15 business days (custom)
Estimated Delivery: 7–15 business days (standard); 3–5 business days (expedited)
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