Mountain bikes have changed. Every improvement to the modern MTB is letting more riders go bigger and faster. Simultaneously, ebikes are experiencing similar evolution, only with more abuse to the drivetrains. All of this puts a tremendous amount of strain on your hubs–the unsung heroes keeping your bike rolling on the trail.
When Industry Nine launched the Hydra platform six years ago, it was a massive improvement over their Torch platform in terms of engagement. Pre-2020, it seemed that brands were still vying for the top engagement spot and the 690 points of engagement for the Hydra made the industry take notice.
If you’ve ever met the Industry Nine team or had the chance to tour their factory in Asheville, North Carolina, you know that they thrive on precision. And the pursuit of perfection. They claim to have over 100,000 Hydra hubs in global use, and they’ve taken all of the feedback from riders across the globe to heart.
“Our goal with Hydra2 was to create a hub that could endure the most extreme conditions and the most demanding riders,” said Jacob McGahey, VP and Head of Product Development at Industry Nine. “By leveraging lab testing, real-world data, and our in-house engineering and manufacturing resources, we’ve achieved a hub that sets a new standard.”
Just what does “a new standard” mean for Industry Nine? It’s a hub that is better in almost every metric while keeping it within a few grams of the original Hydra.

Key improvements:
- Enhanced Axle Strength: A 65% thicker axle engineered for superior stress dissipation.
- Increased Bearing Longevity: Larger 6903 bearings throughout the hub, a new labyrinth channel, and full-contact radial lip seals on the freehub and endcaps for unparalleled protection against contaminants.
- Consistent Bearing Preload: A foolproof design maintains peak bearing performance, regardless of axle tightness.
- Reinforced Pawl Engagement: Larger 5.5mm pawl pockets, providing 26% improved force dissipation to prevent wear and tear.
- Improved Drivetrain Durability: Tougher metal for the drive ring and an additional tooth on each pawl, specifically designed to handle the high torque demands of powerful E-bike motors.
New Scalloped Hubshell

In an effort to minimize weight while increasing the spoke flange strength, the new hub has a scalloped hubshell. Hubs will be offered in Direct Thread System MTN shells with their machined aluminum spokes, or the S-Series MTN for normal steel j-bend spokes. The System hubs are offered in 6-bolt only, while S-Series is 6-bolt or Centerlock.
Thicker Axle, Revised Bearing Preload, New Bearings, New Seals

Just about everything inside the hubshell has been updated as well, starting at the axle. The new axle is 65% thicker to “dissipate stress more efficiently.” That axle now rides inside larger 6903 bearings throughout the hub along with a new labyrinth channel and full-contact radial lip seals to keep the bearings running smoother, longer.
In order to prevent variations in axle tightness from affecting the bearing adjustment, a new preload design has been implemented. Industry Nine describes it as follows:
“The first bearing is pressed into the hub shell, sitting flush with both the shell and the axle. The second bearing is pressed onto the axle, sitting flush with the axle but not the shell, causing a slight amount of compression on the axle. Installing the bearings this way creates a slight compression on the axle, which pushes the bearing rings against the balls. This creates a small amount of friction. When the hub is installed in the frame or fork, the clamping force from the mounting system applies pressure to the axle. This counteracts the initial preload, relieving pressure on the bearing rings and allowing them to spin freely with minimal friction.”
New Freehub





Current Hub Lineup

- 1/1: Budget-conscious product for road, gravel, and mtb
- Solix: Road, gravel, and XC
- Hydra2: Trail, enduro, DH, e-bike
Pricing & Availability plus Hydra 2 e-bike compatibility













SL e-Bike compatible Hydra 2 wheels
- Alloy Enduro-S Series MTN
- Carbon Enduro-S S-Series MTN
SL e-Bike and Full Power Class 1 e-bike compatible Hydra 2 wheels
- Alloy Enduro System MTN
- Alloy DH System Mountain
- Carbon Enduro System MTN
- Alloy Grade-S S-Series MTN
I9 Hydra 2 Grade 300 Wheel Review





