Industry Nine Hydra2 Review

In my latest video, I weigh in on the Industry Nine Hydra2 hubs after riding them for several hundred miles and comparing them to I9’s previous tech: Torch, Solix, and Hydra, three high-engagement hubs I’ve had plenty of experience with over the years. Watch my full Industry Nine Hydra2 review below, and read on for a written version that includes photos from I9’s shop, where Nic Morales captured some images of the Hydra2 being machined and assembled.

Before diving into the Industry Nine Hydra2, let’s take a quick trip down memory lane. Industry Nine was founded in 2004 by Clint Spiegel as an extension of his family’s machining business in Asheville, North Carolina. The company manufactures hubs and spokes, builds wheelsets in-house, and focuses on high-engagement hub systems and CNC-machined components. Their distinctive anodized aesthetics, unique direct-thread spoke system, and lightning-fast engagement hubs really set their products apart.

• 
• 

• 
• 

One of Industry Nine’s key strengths is their control over production. Their hubs and spokes are machined from raw aluminum at their Asheville facility, allowing them to uphold quality standards and refine designs without depending on overseas suppliers. This in-house production also supports their proprietary straight-pull spoke system, which eliminates the need for traditional J-bend spokes and nipples. While this design offers potential advantages in strength and weight, it also means riders must use specific replacement parts. However, with I9’s strong industry presence, most shops are likely familiar with their wheels. Still, it’s never a bad idea to carry spare spokes.

Industry Nine’s Hub History

Industry Nine has been making hubs since 2005, starting with their Legacy hub, which featured a dual-phase, six-pawl system with 120 points of engagement. In 2013, they launched the Torch system, a fully redesigned hub that was lighter, had much better bearing life, and was serviceable. By 2019, I9 saw the need to refine the Torch design, leading to the launch of the Hydra. This introduced a six-phase, six-pawl system, reducing drag by 20% compared to Torch while retooling the drive ring with 690 points, resulting in an incredible 0.52° of engagement.

More recently, in 2023, they introduced the SoliX G and SoliX SL hub platforms, primarily targeting drop-bar riders. These hubs maintained a high-engagement design but with slightly fewer points, 605 in total, resulting in a 0.59° of engagement. Last year, I9 carried that design over to the mountain bike side with the SoliX M. The main difference between Hydra and SoliX is the pawl configuration, with Hydra using a six-pawl system and SoliX opting for five. And now, I9 has introduced Hydra2, which is replacing Hydra in their lineup.

• 2005: The original innovative, quick-engagement I9 hub offered 120 points of engagement using a dual-phase six-pawl system with steel drive rings cut from pre-hardened A2 steel, an innovative process unique to I9.
• 2013: The I9 Torch hub was much lighter and had a more refined design while still using the original high-engagement drive mechanism.
• 2019: Hydra offered 690 points of engagement using a 0.52-degree, six-phased pawl system.
• 2023: SOLiX G/SOLiX SL was released as a new hub platform with refined engagement and durability improvements focused on drop-bar bike applications.
• 2024: SOLiX M offered 605 points of engagement using a 0.59-degree, five-pawl phased system.
• 2025: Hydra2 offers 870 points or 0.41-degrees of engagement with 60% less coasting drag.

Now, to back up a bit. The Hydra hub, introduced in 2019, was Industry Nine’s highest-engagement offering. It used a six-pawl phased mechanism, meaning multiple pawls engaged at different intervals for near-instant response. This system also spreads the load across multiple points, which could, in theory, improve durability. Riders who prioritize quick engagement tend to appreciate the Hydra, while others might not need it (or might not love the noise it generates).

• 
• 

High-engagement hubs generally have more pawls, springs, and ratchet mechanisms that make contact more frequently. This can increase friction and drag, leading to slightly higher resistance compared to lower-engagement hubs. The amount of additional resistance varies depending on the hub design. Some brands, such as DT Swiss, use a star ratchet system that balances engagement and efficiency, while others, such as Hydra with its numerous pawls, might have more noticeable resistance. That said, for most riders, the difference is negligible and often outweighed by the performance benefits of faster engagement. At least, that has always been the case for me.

What’s New?

So, after six years and over 100,000 hubs in the field with a deep well of rider feedback, the goal with Hydra2 seems clear: create a more durable product. And while it may share a name with its predecessor, make no mistake, there’s a lot of new-new going on here. In fact, Hydra2 was pretty much designed from the ground up.

• 
• 
• 

One of the most common weak points I’ve heard about was the original Hydra axle, which broke or failed for some people. To address this, I9 now uses a 65% thicker axle designed to dissipate stress more effectively. They mention, “We also implemented a new butted axle with significantly more material under the driveside hubshell bearing for increased strength and stiffness and changed our bearing preload method to further improve durability.”

• 
• 

Speaking of bearings, they increased the bearing size to using 61903 sealed cartridge bearings while also adding dust seals near both end caps. They also incorporated a radial lip seal to keep bearings cleaner for longer. Beyond that, the revamped hub shell now houses a larger 145-tooth drive ring that I9 claims is made with tougher steel.

• 
• 

Freehub Updates and other Refinements

Once you crack it open, one of the most visible changes is in the freehub body, where Industry Nine added a retaining ring to keep the pawls in place. This is similar to the 1/1 hubs. I never had issues with pawls falling out on the original Hydra, but I did with the Torch. With Hydra2, the pawl pockets are larger, which helps dissipate force by 25% and reduce pocket elongation, though it may also make the pawls more prone to falling out during service—hence the retaining ring.

• 
• 

• 
• 

The pawls themselves have also changed. Instead of two teeth per pawl like the original Hydra, Hydra2’s pawls now have three teeth, increasing engagement by design. The result is 870 points or 0.41 degrees of engagement with 60% less coasting drag, according to the brand.

• 
• 

The hub shell itself received a subtle redesign, moving away from the blocky look of the original Hydra in favor of more rounded features, similar to the SoliX. Despite all the changes, Hydra2 is still available in all of I9’s signature anodized colors, still uses the direct-thread hubshell and machined aluminum spokes, and retains the six-pawl, six-phase engagement system that made Hydra so popular in the first place.

In Use

Similar to all I9 hubs, the Hydra2 features tool-free freehub removal, meaning you can pop off the freehub with the cassette still on if you want to clean it out. I really like this, as it makes servicing easier and is also necessary if you need to replace a spoke. Another noticeable difference when reinstalling the freehub body is how simple it is. Just pop it back on. No more aligning the sleeve within the freehub body and the axle, something that always annoyed me on the Hydra. That said, I’ve noticed that when you remove and install the free hub body, the radial lip seal starts to deteriorate rather quickly, as you can see the pawls cut into the seal itself, which has me a little concerned that it’s not going to work as intended after a few times servicing the hub.

I ran the new I9 Enduro 350 system wheels with Hydra2 hubs on my new Goodday Gila Monster, and they’ve been a joy. Obviously, it looks great, but the hub also feels fantastic. In fact, if you spin the freehub body on both the Hydra and Hydra2, you’ll not only hear a difference, but it feels smoother and easier to turn.

• 
• 

This winter, I swapped between a few wheelsets, and it was pretty wild going back to an older Torch hub. The difference between 120 and 807 points of engagement is night and day. Yet, 120 is still pretty fast compared to many other hubs on the market. I was actually out testing some bikes this spring with hubs that had even lower engagement than 120, and I struggled in slower technical sections where you have to briefly stop pedaling to fix your balance before re-engaging. Every millisecond helps, and after using the Hydra—and now Hydra2—it was tough going back to a slower system.

• 
• 

• 
• 

Now, about resistance. As I wrote, it’s hard to actually feel, especially on singletrack. Sure, not everyone needs super-fast engagement. If you don’t, there are plenty of options out there, but I9 loves engagement. When you think about coasting drag—60% less drag on the Hydra2—after crunching some numbers, I’m saving a few minutes over a long day in the saddle. It’s nothing game-changing for me, but if you’re looking to race or if every minute matters to you, it might be a factor worth considering.

• 
• 

So far, I’ve only put about 300 miles on this hub, which is not much in the grand scheme of things. The bearings are just wearing in and feel pretty darn good, so I’ll need to report back on longevity down the road. After removing the cassette for the first time, I noticed some dark grime, but large debris and grit were stuck to the seals and didn’t make it into the hub itself. Still, I do worry about the durability of those seals. This hub has only seen desert conditions and a few dry local rides, so no water exposure yet, but time will tell.

Industry Nine Hydra2 Pricing

The Industry Nine Hydra2 hubs start at $700 USD for the hubset alone and are available in 28- and 32-hole configurations and with either center lock or 6-bolt rotor options. If you’re looking at complete wheels, it’s also available in a variety of System Wheel builds. Carbon System Mountain Wheels start at $2,295, Alloy System Mountain Wheels start at $1,395, and S-Series wheels (steel spokes instead of aluminum anodized) start at $995 USD. Here’s a full list of options. Note that the options marked with a ⚡ are rated for SL e-bikes (65Nm/44lbs/20kg); ⚡⚡ is rated for full-power Class 1 e-bikes.

System MTN

S-Series MTN

Hub Only

Several of us on the BIKEPACKING.com team use and really like the original Hydra hubs. So, is it worth upgrading? The new Industry Nine Hydra2 appears to be more durable with a burlier axle and bearing design, has less drag, and offers even more engagement. But is more always better? Let me know what you think in the conversation below!

Learn more about the Industry Nine Hydra2 over at IndustryNine.com.

Further Reading

Make sure to dig into these related articles for more info...