Velocity Fat Rear Black ISO 6 Bolt Disc Hub
The Velocity Fat hub is Velocity USA's fat-bike hub: the Standard ATB design widened to 150mm front and 197mm rear thru-axle spacing, with a machined aluminum shell, sealed cartridge bearings, a pawl freehub and a 6-bolt rotor mount, assembled in Florida. This page covers the Velocity Fat Rear Black ISO 6 Bolt Disc Hub.
Fat-bike hubs take a beating from the grip of a 4in tire and the salt and slush of winter riding, and the Fat hub's sealed bearings and simple, serviceable freehub suit that use. It is priced so the budget can go into a good rim.
The Velocity Fat hub comes from us only as a finished wheel: pick the rim, spokes and nipples, and we lace, tension and true it by hand in Georgia before it ships.
Design and construction
The Standard ATB hubshell is machined from aluminum with conventional J-bend flanges and an ISO 6-bolt rotor mount. Bearings are sealed cartridge units in common sizes, so replacement years down the line is a ten-minute job with a bearing press. The rear freehub runs pawls on a hardened ratchet ring and swaps between Shimano HG and SRAM XD bodies. End caps convert the hub between quick-release and thru-axle standards; the configurator lists the axle and driver options for the version on this page.
How it rides
A Velocity Fat hub does its job quietly under a fat bike. Engagement is quick enough for snow and sand climbing, the bearings spin cleanly, and the seals keep slush out. It is a trail and winter fat-bike hub; for fat e-bikes we would recommend a heavier-duty hub.
Specifications
| Position | Rear |
|---|---|
| Axle options | QR 5x170mm Rear, Thru Axle 12x177mm Rear, QR 5x190mm Rear, Thru Axle 12x197mm Rear |
| Driver bodies | Shimano HG 8,9,10,11 & Road 12spd, SRAM XD 10,11 & MTB 12spd |
| Drillings | 32h |
| Spoke head | J-bend |
| Brake | 6-bolt disc |
| Left flange diameter | 58 mm |
| Right flange diameter | 58 mm |
| Left center-to-flange | 46 mm |
| Right center-to-flange | 46 mm |
| Spoke hole diameter | 2.6 mm |
| Weight | 340g |
| Material | Aluminum |
| Finishes | black |
About this listing
What sets this listing apart from the other Fat versions: 6-bolt rotor mount, QR 5x170mm, Thru Axle 12x177mm, QR 5x190mm, Thru Axle 12x197mm, 32h drilling, about 340g, in black. Pick the one that matches your frame and rotor and the rest of the hub is identical.
Six-bolt is the original disc mount and still the most universal: any ISO 6-bolt rotor from any brand bolts straight on, rotors are cheap and easy to find anywhere, and the six-bolt flange is a robust, simple interface that has been on mountain bikes for twenty-five years. Centerlock rotors do not fit it.
Sizes, fit and compatibility
The Velocity Fat Rear Black ISO 6 Bolt Disc Hub comes in the drillings listed on this page in 150mm front and 197mm rear thru-axle spacing with a 6-bolt rotor mount and Shimano HG or SRAM XD freehub. It takes J-bend spokes in any gauge; we build most Fat hub wheels with Sapim Race or DT Competition spokes and brass nipples.
It pairs with the DT Swiss BR 710, Sun Ringle Mulefut, Surly and HED 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 a wheel around it
Offered for fat bike and tandem and e-bike builds in our Custom Wheel Program. Start with the Velocity Fat Rear Black ISO 6 Bolt Disc Hub and the configurator pins it for you, then checks each choice you make against it.
Testing, standards and warranty at Velocity
Velocity USA offers hubs under its own name for road, gravel, mountain, touring, tandem and track use. Velocity's product pages do not state where the hubs are manufactured, and the company publishes no bearing-life, freehub-durability, sealing, load or fatigue test figures and no third-party certification for hubs; the specification tables on its hub pages (weight, bearings, axles) are blank and refer customers to the tech page.
Warranty matches all Velocity products: defects in material and workmanship for the life of the product, excluding normal wear and tear, accidents, misuse, improper assembly or maintenance; repair or replacement at Velocity's discretion.
Velocity states cassette-body pawls should be inspected and lubricated once a year or more depending on use and environment; cassette bodies come in Shimano, SRAM XD/XDR and Campagnolo fitments.
Velocity's videos
Sources on Velocity's site:
- Tech - Velocity USA (Hub Technology section)
- Standard Hub - Rear - Velocity USA
- Road Race Hub - Rear - Velocity USA
- Sealed Cartridge Bearings - Velocity USA
- Hubs collection - Velocity USA
The figures, certificates and media above are Velocity's own. ProWheelBuilder does not run these tests; our part is the wheel we build on the hub.
Building it at ProWheelBuilder
Velocity makes the Fat; ProWheelBuilder is an independent custom wheel builder in Georgia and not the manufacturer. We measure the rim before we cut a spoke, bring the wheel up in three or four rounds with a gauge, stress-relieve it between rounds and true it last, then tape it and fit a valve if you want it tubeless.
Only compatible hubs and spokes appear in the configurator, impossible combinations are struck through rather than hidden, and the price is live.
Warranty
Velocity's warranty. Velocity warrants its rims against defects in material and workmanship for the life of the product, repairing or replacing at its option. Normal wear, accidents, misuse, improper assembly and poor maintenance are excluded.
ProWheelBuilder. Built into a wheel by us, this part is covered by our own one-year wheel warranty on top of the maker's. For a year we replace broken spokes whatever caused them, and we cover the labor on the wheel - truing, re-tensioning, a rebuild if it needs one. If a rim or hub fails and its maker covers it, we run that claim for you; if the maker says no, you get an eligible replacement rim or hub at 25% off retail. You pay the shipping each way. Wheels built from parts you send us are excluded.
Full terms are on our Policies & Warranty page.
Fat Rear Black 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 Velocity Fat hub?
150 x 15mm thru-axle front and 197 x 12mm thru-axle rear, the current fat-bike standards.
Which freehub bodies fit the Fat hub?
Shimano HG and SRAM XD, selectable in the configurator for the rear hub.
Is the Fat hub good for winter riding?
Yes. Sealed cartridge bearings and simple pawl internals shrug off slush and salt; a clean and regrease each spring keeps it happy.
Is the Fat hub e-bike rated?
No. For fat e-bikes choose a heavier-duty hub such as a DT Swiss 350 Big Ride.
Which axle spacing does it fit?
QR 5x170mm Rear or Thru Axle 12x177mm Rear or QR 5x190mm Rear or Thru Axle 12x197mm Rear. 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.
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.
