Onyx Fat Bike Front ISO 6 Bolt Disc Hub
A fat tire at 6 psi has so much grip that any dead stroke on a snow climb is lost momentum, and the Onyx has none. This page covers the Onyx Fat Bike Front ISO 6 Bolt Disc Hub.
The Onyx fat bike hub is built to order here. Choose the rim, spokes and nipples in the configurator; the wheel leaves Georgia laced, tensioned and trued.
Design and construction
Fat-bike spacing asks a lot of a hub: 150mm at the front and 177 or 197mm at the rear puts the flanges a long way apart and the bearings under a wide, twisting load.
A front hub is a bearing carrier with flanges, and that is the whole job of the front fat bike: two sealed bearings on a stiff axle, end caps for your fork's standard, and flanges spaced to give the spokes a good bracing angle on the rotor side. There is nothing to engage and nothing to swap. Everything written about freehubs and engagement applies to the rear hub only; what you get up front is the same shell quality and the same seals without any of the moving parts.
How it rides
It is the fat-bike hub for riders who want the best.
Front wheels on disc bikes take a beating from braking: the rotor side sees the whole braking torque and the spokes on that side run at higher tension. That is why we build the front fat bike with the rotor-side spokes crossed and tensioned to the rim's limit, and why the hub's flange spacing matters more than its weight. Ridden on a rim-brake bike the same hub makes one of the lightest, simplest front wheels there is.
Specifications
| Position | Front |
|---|---|
| Axle options | QR 5x135mm Front, Thru Axle 15x135mm Front, Thru Axle 15x142mm Front, Thru Axle 15x150mm Front |
| Drillings | 32h, 36h |
| Spoke head | J-bend |
| Brake | 6-bolt disc |
| Left flange diameter | 57 mm |
| Right flange diameter | 57 mm |
| Spoke hole diameter | 2.6 mm |
| Weight | 278g |
| Material | Aluminum |
| Finishes | baby blue pc, black ano, black aura pc, black matte ano, blue ano, blue candy pc, clear ano, gold ano, green ano, green anti freeze pc, green florescent pc, green kawasaki pc, orange ano, orange florescent pc, pink ano, pink florescent pc, purple ano, purple candy pc, red ano, red candy pc, turquoise ano, white pc, yellow cardinal pc, yellow florescent pc |
Which version this is
Version notes. 6-bolt rotor mount, QR 5x135mm, Thru Axle 15x135mm, Thru Axle 15x142mm, Thru Axle 15x150mm, 32h, 36h, about 278g, in baby blue pc, black ano, black aura pc, black matte ano, blu. If your frame or fork uses a different standard, the other versions of the fat bike on this site cover it.
This is the 6-bolt fat bike: the rotor bolts to a flange with six T25 bolts, which is the mount most mountain and gravel rotors still use and the easiest to find a rotor for on the road. If you run centerlock rotors, choose the centerlock version of the same hub instead.
Sizes, fit and compatibility
J-bend spokes in any gauge; we build most fat wheels with Sapim Race or DT Competition spokes and brass nipples.
It pairs with the HED Big Deal and Big Aluminum Deal, DT Swiss BR 710, Sun Ringle Mulefut and Surly fat rims in the catalog. Pick fat bike as your bike type in the configurator and it recommends a spoke count and lacing pattern for the offset.
Build it with us
We build this hub to order. Open the Custom Wheel Program with the Onyx Fat Bike Front ISO 6 Bolt Disc Hub already selected and pick the parts around it; it is offered for MTB single-speed and fat bike builds, and the configurator will not let you assemble a combination we would not build.
Onyx's testing and certifications
Onyx Racing Products hubs are made in the USA by a division of Christianson Systems in Minnesota; in a 2020 interview the company described itself as "Minnesota made and owned". Bearings are hybrid ceramic on the Classic line and an upgrade option on Vesper; the distributor states "Since early 2025 all Onyx hubs have been assembled with high-quality Japanese EZO bearings." Onyx specifies a grease service temperature range of -58°F (-50°C) to 248°F (120°C). It publishes no bearing-cycle, salt-spray, ISO 4210 or load-test figures. Onyx's specifications state radial lacing is not permitted on any Onyx hub and set a maximum spoke tension of 120 KgF.
The European distributor recommends "a seasonal check-up 2-3 times a year".
Inside the Onyx shop
Certifications
- Made in USA (Minnesota) — Onyx states it is "Minnesota made and owned"; retailer and distributor listings state "Made in the USA" (source)
- 5-year limited hub warranty — Hub 5 years to original owner; sprag clutch 1 year against manufacturing defects; wheel builds 1 year (source)
- E-bike approval (Classic hubs) — Distributor states Classic hubs are e-bike approved for mid-drive units with peak power output up to 1500W (source)
Sources on Onyx's site:
- Onyx Racing Products - Tech (site returned 403 at time of research)
- Onyx Racing Products - Limited Warranty (U.S. Only)
- Onyx Racing Products Wheels - Warranty
- November Bicycles: In their own words - Onyx Racing Products (April 17, 2020)
- Onyx Hubs Europe - Technology
Everything in this section is published by Onyx. ProWheelBuilder is the wheel builder, not the tester, and the hub reaches us as the maker ships it.
Building it at ProWheelBuilder
Onyx makes the fat bike; ProWheelBuilder is an independent custom wheel builder in Georgia and not the manufacturer. The build is the same every time: measured ERD, spokes cut to the half millimeter, staged tensioning with a gauge, stress relief, a final true, and tubeless tape and a valve on request.
The configurator shows only rims and spokes that fit the fat bike drilling, strikes through combinations that are not made, and prices the wheel live.
Warranty
Onyx's warranty. Onyx Racing Products covers its hubs under a five-year limited warranty against defects in materials and workmanship.
ProWheelBuilder. Wheels we build around this part are covered by our own one-year warranty alongside the maker's. Within the year: broken spokes replaced regardless of cause, and the labor on the wheel - truing, re-tensioning or a complete rebuild - included. A manufacturer-covered rim or hub failure is a claim we make and manage for you; one they will not cover is answered with an eligible replacement at 25% off retail. Shipping each way is yours. Parts you supply yourself fall outside it.
Full terms are on our Policies & Warranty page.
Fat Bike Front ISO 6 Bolt Disc Hub questions
Will my rotors fit this hub?
This is the 6-bolt version: any ISO 6-bolt rotor bolts straight on with six T25 bolts, which is still the most common and the easiest rotor to replace anywhere. Centerlock rotors do not fit it - for those, take the centerlock version of the same hub, listed separately.
What spacing is the Onyx fat bike hub?
150 x 15mm front and 177 or 197 x 12mm rear, selectable in the configurator.
Is ProWheelBuilder the manufacturer of the Onyx Fat Bike Front ISO 6 Bolt Disc Hub?
No. The hub is made by Onyx; we are the wheel builder in Georgia who laces it into a finished wheel to your spec and stands behind the build.
Which axle spacing does it fit?
QR 5x135mm Front or Thru Axle 15x135mm Front or Thru Axle 15x142mm Front or Thru Axle 15x150mm Front. Measure between the inside faces of your dropouts if you are unsure, or text us.
Does it need special spokes?
No. It takes standard J-bend spokes, which the configurator offers in every gauge and finish we stock.
How long will the wheel take?
Build time comes down to parts availability rather than bench time. The estimated ship date is shown in the configurator before you check out.
Not sure? Text or leave a voicemail on 470-253-0929 or email info@prowheelbuilder.com — you will be talking to the people who build the wheels.
