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

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

$310.00 USD
$350.00 USD $310.00 USD
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Free shipping  |  VAT included in EU & USA
Weave
Spoke QTY
Weight

The Bola 700C 40mm asymmetric carbon tubeless rim - a 28mm-wide offset-bed Toray aero rim for climbing, all-round road and wind-exposed builds.

The climber's aero rim: the Bola 40mm asymmetric tubeless offsets the spoke bed for a stiffer, truer wheel while keeping 40mm of aero. Forty millimetres of T700/T800 carbon, 28mm wide, sold rim-only.

Buying Guide.

Weight tier - Extreme Light ~350g: the climber's aero pick - lightest end, offset bed for a stiff, true rear wheel.

Weight tier - Ultralight ~370g: 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 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 road version; the 40mm U-shape tubeless is the symmetric version.

Adjacent depth: the 35mm asymmetric climbs better; the 50mm offset tubeless adds aero.

Target Audience & Usage Notes.

Target audience.: Climbers and riders in windy terrain.

Rim-only.

Seat tubeless beads with a compressor; respect 110 psi and 105kg.

Not for flat TT maximum speed or riders over 105kg.

The Ride That Awaits.

Lace it to a climbing hub, seat a 28-32c tubeless, and feel the offset bed build a stiff, true rear wheel: 350g of rim, 40mm of aero, calm in the wind. Climb, sprint, repeat - the aero climber you are was waiting for this. 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): 558
Weight Tier: Extreme Light 350g / Ultralight 370g / Superlight 390g / Standard 425g (+/-10-15g)
Trade-offs & Considerations
Aero vs Crosswind: The 40mm depth is the versatile fast option; it saves about 4.0W versus a 30mm rim at 40km/h, and at 10° yaw the 28mm outer width keeps crosswind steer manageable — faster than the 35mm but calmer than the 55mm.
Weight vs Stiffness: The Extreme Light tier (350g) saves about 75g versus the Standard tier (425g) (±5g); lateral stiffness holds within 3% because the asymmetric spoke bed and the 28mm outer wall are shared across tiers.
Tire-Type Trade-off: The hooked bed (21mm internal) allows higher pressure, while the hookless option (23mm internal) runs wider ETRTO-certified tyres around 72–87 psi; both accept 25c–40c tubeless.
Sourcing & Delivery Trade-off: Stock 20/20 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: >60J (Higher than ISO 4210-7)
Flatness: <0.25mm (internal QC)
Roundness: <0.3mm (internal QC)
Max Spoke Tension: >350 kgf (internal QC, spoke breaking tension)
Ultimate Strength: >200 kgf (internal QC, static spoke-hole point load)
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 (ISO 622) road frames; disc or rim brake per hub
Tire Type: Tubeless-ready clincher
Tire Width: 25-40mm
Valve: Presta
Brake: Disc or rim brake (hub-dependent)
How It Compares
ModelWeightDepthWidthPrice
700C 40mm Rim 28mm Extreme Light 350g / Ultralight 370g / Superlight 390g / Standard 425g (+/-10-15g) 40mm 28mm See store
Model A ~430g 50mm 28mm $1,399
Model B ~430g 50mm 27mm $249
Model C ~420g 50mm 30mm $389
FAQ
What spoke drillings are available, and which brake type is this rim rated for?
Spoke drillings and brake rating depend on the build option, selectable at checkout. If you plan to lace your own wheel, confirm the drilling and brake type with Bola before ordering so the rim matches your hub and frame.
What is the maximum spoke tension for this rim?
Drive-side / disc-side max tension is 130–140 kgf, with the non-drive side adapted to match; spoke holes are locally reinforced inside the carbon layup to prevent pull-out cracking.
Will the rim crack on rock gardens or bottom-outs at low pressure?
The rim bead area uses a thickened impact-reinforced layer; impact testing passes >60J extreme impacts (above the ISO 30J standard). Inner widths of 21/23mm accept wider tyres, which deform to absorb shock at low pressure.
What tyres can I mount on this rim, and what pressure should I run?
The 21mm hooked / 23mm hookless inner widths take tubeless tyres from 25mm to 40mm, with 28–32mm the aero sweet spot.
Will I really pay no customs or VAT for delivery to the US and EU?
Yes. The Economy channel ships DDP — duties and VAT are fully prepaid by us, cleared in advance, delivered to your door with no extra payment to customs or the courier.
Warranty & Shipping
Warranty Period: 3 years
Crash Replacement: 30% discount on replacement parts
Processing Time: In stock: 1–3 business days · Out of stock or custom order: 7–15 business days
Shipping method: FedEx/UPS/DPD/EMS Economy (free with duties & VAT included in USA & EU) · Expedited option available
Estimated Delivery: Economy 7–20 business days · Expedited 3–7 business days, customs clearance excluded
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