Deal Of The Week—Save On Road Tops. Shop Now
This carousel displays a list of buttons that updates the main product image when a button is clicked
  • Options
  • Detail Images

ONYX Racing ProductsOnyx MTB Rear Boost Hub

Sale 10% OffCurrent price:$399.98 Original price:$445.00

Item # ONY0002

Select options
  • Cancel
  • Select options
  • Black, 12x148, HG, 32H ($399.98)
  • 100% Guaranteed Returns
  • Free Shipping on orders over $50

Item # ONY0002

Onyx MTB Rear Boost Hub

ONYX Racing Products came about as a father's desire to provide his BMX racing son with a hubset that was faster engaging and smoother rolling than any other option on the market. Naturally, for BMX where starts are critically important as well as getting back on the gas after pumping, cornering, and jumping, lightning fast engagement makes a huge difference and those benefits carry over to the mountain bike side too. Whether you're pedaling out of a turn in a short track race to get a gap on your rivals, negotiating a technical climb, or simply want to coast without it sounding like a swarm of bees are chasing behind you, the MTB Rear Boost Hub from ONYX Racing Products is an excellent option with its patented sprag clutch rear hub transmitting pedaling power into forward momentum.

These hubs are made in the USA and the shell is machined from 7075 aluminum for strength and durability. It, like all Onyx hubs, spins on high quality ceramic hybrid bearings, which are lighter, smoother, and last longer than its steel counterparts. They are constructed to very tight tolerances and Onyx gives you the ability to adjust the bearing preload with a threaded collar and titanium cinch bolt, preventing overly tight or loose hubs by allowing for adjustments while mounted in the dropouts. The star of the show is its sprag clutch mechanism for instant engagement under power and instant disengagement while coasting. As a bonus, the hubs feature quiet operation and no coasting drag so you can take in the scenery and enjoy shredding the singletrack in silent bliss. We also really appreciate that the hubs are easily disassembled and can be serviced by a home mechanic. This particular version has 32 holes, Boost spacing, 6-bolt rotor mounts, and is available with a heat-treated hardened stainless steel Shimano HG freehub or SRAM XD driver.

  • A quick engaging and silent mountain bike rear hub with low drag
  • 7075 aluminum hub shell for strength and durability
  • Ceramic hybrid bearings reduce friction for less rolling resistance
  • Adjustable bearing preload extends the bearing life
  • Titanium pinch bolts help shed some weight
  • Non-contact seals keep out water, mud, and grime
  • Sprag clutch engages and disengages instantly
  • Made in the USA and backed by a 5-year warranty

Tech Specs
Material[shell] 7075 aluminum, [bearings] ceramic hybrid, [bolts] titanium, [freehub body] stainless steel
Hub TypeRear, Boost, Mountain
Rotor Compatibility6-bolt
Spoke Count32
Recommended Usecross-country, enduro, trail
Manufacturer Warranty5 year limited

Claimed Weight

Claimed weights are provided by the vendor.

Have questions? Chat with a Gearhead


Actual weights are measured in-house by the Competitive Cyclist team.

Have questions? Chat with a Gearhead

What do you think about this product?



Is the HG version 11 speed compatible?

>Rating: 5

Silent and smooth

I've put it through the wringer

I bought this after having gone through a number of rear hubs and having the lack of engagement leaving me hitting my pedals on rocks and roots trying to get through local narrow, chunky trails. Decided I'd choose between the I9 and the Onyx. Looked through the reviews and while the Onyx were reported to be heavy as a tank, the instant engagement always got rave reviews. So, I ordered a rear hub from Onyx and first thing I noticed when I got it was that....oh boy they're not kidding. This thing is heavy. If you're building a sub 25lb XC rig, probably not going to be your rear hub of choice at >1 pound on its own. However, if you don't care about the weight of the rear hub (I ride a 34lb Pole Evolink, so weight weenie stuff already out the window), you may really end up loving this hub. Once laced up to my rims and onto my bike, I can honestly say I've never seem something roll so smoothly and effortlessly. There is really no drag whatsoever on this hub when coasting. Pedaling brings about instant engagement, but not in the form of a clunk or a click, but more of a smooth "whoosh" of power....I will say that there is maybe a degree or two of "give" when you begin to put the power down, but it's unnoticeable really. I'll admit that when riding through a forest, it's a bit odd not hearing anything but your tires rolling on the dirt, which can be a good thing if you want to sneak up on unsuspecting fellow riders or animals, but probably could spook some people you ride with. Overall, it's a great hub that is really well built and functions exactly as every review I read said it did. Super happy with my purchase

>Rating: 5

Silent, instant-engaging magic.

I've put it through the wringer

Got these hubs as part of a new wheel build and was wary about the extra weight. One ride into it I didn’t care about the weight. Engagement is instant but soft in a way—none of the “clunk” with engagement—and there really is something magical about bombing a long flowy descent with no freehub noise. And they’re beautiful. Seriously, just scroll past the weight and try these hubs. They’re amazing.


Can you get the 28h version of these hubs? Specifically the rear boost sram xd?