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 – 12×148, QRx141
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.
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.
Worth knowing if you might change drivetrain later: HG and XD share the same end caps, but Microspline uses different ones. Swapping to or from Microspline means new end caps as well as a new freehub.
Will this fit my frame?
This is the Boost version, running 12×148 Boost or QRx141 end caps. That covers most trail and enduro frames built from roughly 2016 onwards.
If your frame is 12×142 or 135mm, that’s non-Boost and you want the non-Boost version. If it’s 157mm, that’s Superboost and there’s a separate hub again. Measuring across the inside of the rear dropouts is the quickest way to be sure – or send us the frame make, model and year and we’ll confirm. It’s the easiest thing to get wrong when buying a rear hub.
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. In practice the pedals pick up almost immediately when you ratchet through technical climbing.
Be aware this is the previous generation: the Hydra2 has superseded it, and what you see here is run-out stock. The Hydra2 brings a thicker axle, larger bearings and beefed-up pawl internals built for e-bike torque. That said, on a normal trail bike the Hydra remains a superb hub, and at run-out pricing it’s the best value in the range while it lasts.
Should I choose 28 or 32 hole?
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.
Don’t assume more spokes is automatically better – plenty of enduro wheelsets run 28 hole deliberately, for a more compliant wheel that tracks better on rough ground. Rear wheels take more punishment than fronts though, so if you’re genuinely torn and riding hard, 32 is the safer default. Tell us the rim and we’ll confirm.
