Please advise Freehub (Hyperglide, Microspline or XD) and/or End Caps in order comments once your selected hub has been added to the cart.
Compatible End Caps – 12×150, 12×157
To make our most advanced trail, enduro, E-bike, and DH hub even better, we put durability at the forefront, systematically eliminating potential failure points using data gleaned from the 100,000+ Hydra hubs in use around the world.
The result is a hub that can shrug off extreme use by the most demanding riders. Here’s how we achieved it:
- A 65% thicker axle that’s been redesigned to dissipate stress more effectively.
- Larger 6903 bearings throughout, and a new labyrinth channel and full-contact radial lip seal to keep out elements that cause premature bearing wear.
- A new, foolproof design to ensure consistent bearing preload, regardless of variations in axle tightness.
- Larger, 5.5mm pawl pockets that dissipate force 26% better, preventing stretching and elongation of the pockets over years of use.
- Tougher metal for the drivering and an extra tooth on each pawl, guaranteeing Hydra2 can easily handle the torque of the most powerful ebike motors.
In our effort to make the Hydra2 hub bomb-proof, bullet-proof, and Brandon-proof, we didn’t compromise on meaningful performance gains, and the next generation has both quicker 0.41° engagement and 60% less coasting drag than its predecessor.
Combine I9’s trademark direct thread hubshell and machined aluminum spokes, and you’ve got a hub system with brains, brawn, and beauty — a piece of rideable art built by some of the most innovative engineering minds in the cycling industry.
For the next generation of riders, bikes, and trails that demand the very best, Hydra2 is the pinnacle of hub performance.
Do I need Superboost or standard Boost?
This is the Superboost and DH version, taking 12×157 Superboost or 12×150 DH end caps. Superboost frames measure 157mm across the rear dropouts; downhill frames are usually 150mm.
If your frame is 12×148, that’s standard Boost and you want the Boost version of this hub 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 one in the order comments and we’ll fit it before it ships.
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 as well.
Should I buy the Hydra2, or save money on the original Hydra?
The Hydra2 is the current generation. The original Hydra has been superseded and what’s left is run-out stock, so the question is really whether you want the current model or the last of the previous one.
For a DH or Superboost build we’d say take the Hydra2. The 65% thicker axle, larger 6903 bearings, bigger pawl pockets and extra tooth on each pawl were all aimed at surviving e-bike torque and downhill abuse, which is exactly the load this hub sees. Engagement improved too, 0.41 degrees against 0.52, though that’s the least of the reasons.
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.
