Please select Freehub (Hyperglide, Microspline or XD) and/or End Caps from HERE after your selected hub has been added to the cart.
Compatible End Caps – 12×150, 12×157
Industry Nine Classic hubs are the heart of your wheelset, everything revolves around them, literally. Every Classic mountain hub is made start to finish in our Asheville, NC machine shop. From turning and milling bar stock 7075-T6 aluminum for shells, axles and encaps, wire EDM cutting A2 tool steel for pawls and driverings, to our own in-house anodization lab, every step of design, engineering, manufacturing and assembly is done on premises to our exacting standards.
Hydra Classic mountain hubs are loaded with features every rider will appreciate such as revolutionary 0.52° engagement, generously low weights and an intuitive layout that can be serviced without any proprietary tools. Our range boasts a universe of standard options in terms of axle fit, spoke hole drillings, disc rotor mounting, freehub bodies, and colors.
Do I need Superboost or standard Boost?
This is the Superboost and DH version, running 12×157 Superboost or 12×150 DH end caps. Superboost frames measure 157mm across the inside of the rear dropouts; downhill frames are usually 150mm.
If your frame measures 148mm, that’s standard Boost and you want the Boost version instead – same hub, different width. This is the single easiest thing to get wrong when buying a rear hub, so measure your dropouts or send us the frame make, model and year and we’ll confirm before you order.
Which freehub do I need – Hyperglide, Microspline or XD?
It depends on your cassette. Hyperglide (HG) covers 11-speed Shimano and SRAM’s 12-speed NX. Microspline is for Shimano 12-speed. XD is for SRAM Eagle 12-speed. Tell us which you need in the order comments.
If you might change drivetrain later, note that HG and XD share the same end caps while Microspline uses different ones – so swapping to or from Microspline means new end caps too.
How does this compare to the Hydra2?
The Hydra has 690 points of engagement, 0.52 degrees between them – still quicker than almost anything else on the market, and on steep technical ground the pedals pick up almost immediately when you ratchet.
Be aware this is the previous generation: the Hydra2 has superseded it, and what you see here is run-out stock. On a DH or Superboost build that matters more than elsewhere in the range, because the Hydra2’s thicker axle and beefed-up pawl internals were designed for exactly these loads. The Hydra is still a superb hub at run-out pricing – but if this is going on a heavy, hard-ridden bike, the Hydra2 is the one built for it.
Should I choose 28 or 32 hole?
For a downhill or Superboost build, 32 unless the rim says otherwise. This hub goes into wheels that get hit hard, and the extra spokes spread that load.
That said, let the rim decide – follow the rim manufacturer’s guidance for whatever you’re lacing to, and match the hole count if you’re rebuilding onto a rim you already own. More spokes isn’t automatically better; plenty of enduro wheelsets run 28 hole on purpose for a more compliant wheel. Tell us the rim and we’ll confirm.
