Review: Onyx Racing Ultra Cassette Hub

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For the better part of the last year I’ve been riding a cassette hub from Onyx Racing, a Minnesota based manufacturer that’s relatively new on the scene. The story of how Onyx Racing came to be is very reminiscent of how so many companies started off back in the early days of BMX. Dad’s son gets into racing, dad wants him to have the absolute best possible bike, dad decides that he can make something better than what’s out there. In this case that dad was Jim Gerhardt, and his son’s hubs that he set out to improve would eventually evolve into the Onyx Racing brand. Making a set of hubs (more specifically a cassette hub) is a pretty ambitious endeavor. Jim is no ordinary track dad though! His vast knowledge of precision design and machining attained through years of running his family’s company that manufactures specialty farming equipment meant that he was more than qualified to take on the job. It’s been a few years since Jim first set out to make a better set of hubs for his son. Over those years the hubs have been refined and have gained quite a following from other people looking for the very best hubs that money can buy.

At the heart of the Onyx cassette hub is what is known a sprag clutch, a type of one way bearing that gives the hub some unique properties not found in other cassette hubs that use traditional spring and pawl designs. The most notable of those properties is that it offers instant pedal engagement. Inside of the hub, hardened inner and outer steel races contain of a series of angled cam shaped steel wedges called sprags. As soon as forward pedal pressure is applied the sprags wedge themselves against the insides of the races and that is what provides that instant engagement. Since the sprags only contact the races when you’re pedaling, the hub is free to spin without the drag of the mechanism that provides forward movement. This means that not only does Onyx’s cassette hub spin almost as well as a front hub does, but it’s also just as quiet. To really ensure that their hubs are the best spinning on the market Onyx also decided to spec them with ceramic hybrid bearings.

The two things that intrigued me most about Onyx’s hubs were how well they spun and the fact that they were silent. I really wondered what it would be like riding trails with a completely silent hub, especially coming off of what has to be the loudest hub on the market, a Profile Elite. Since it was the middle of winter when I first got my hands on an Onyx Hub, I had to wait a few months to get that answer. I did cruise the streets a bit with it and the lack of sound was definitely noticeable, but just as noticeable was something that I hadn’t even considered. Since the sprags only engage when you pedal forward, you don’t get that vibration coming from the hub’s mechanism like you do from hubs that use springs and pawls. I found that extremely weird even just riding around my house. The best way that I can think to describe it is that it felt like you were almost gliding along.

Fast forward a few months and the trails were finally opened up and I could start getting some answers as to just what it would be like riding this hub in the woods. The first couple of times I rode it at the trails I really didn’t think much of it. Yes it was silent, but after a few laps the novelty of that wore off and I stopped thinking about it. I rode the hub at my spot exclusively for the first few months. My spot is kind of wide open the whole way down, meaning that you don’t need to slow down at any points through the lines. Remember that, cause that’s an important fact for later. Really the only thing that came up riding the hub at my spot was that people couldn’t hear me coming at all. It became a joke that I would just appear at the end of lines. That did make for a few close calls and even one collision, but my woods are extremely thick so I chalked it up to that being as much of a contributing factor as the silent hub was.

Posh was the first set of trails that I rode the hub where there are lines where you really have to control your speed as you go through them. The Sidewinder line is probably the most notorious for that because you’re in for one hell of an over clear if you don’t slow down a bit before the step down into the valley. I’ve ridden the line plenty of times before but not having that audible feedback from the hub made it feel like I was just taking shots in the dark at slowing down. At one point I definitely didn’t slow down enough and I was treated to that lovely feeling of watching the landing go by as I sailed out to flat. Months later and my wrist and ankles are still feeling that! After that one I decided to call it quits on Sidewinder for the day and stick to stuff where slowing down wasn’t so critical.

The drive back gave me plenty of time to think about things. One thing that I couldn’t figure out at first was why would the hub being silent have such of an effect on me being able to judge speed. I’ve ridden with headphones on plenty of times and was still perfectly capable of knowing how fast I was going. Yet with this hub it was like I had lost all connection with my bike. What I finally realized is that it wasn’t just that the hub was silent that was causing that disconnect. It was also the fact that you don’t get any mechanical feel from the hub’s mechanism. I thought back to that first time riding the hub around my house and how weird I thought it was that the lack of vibration made it feel like you were just gliding along. Up until this point I had never even considered that the vibrations transmitted through your bike from a hub’s mechanism helps play a part in how you judge speed. The more I thought about it though, the more sense that it made. With the silent hub not only were you losing a sense in the form of hearing, but also in the form of feel. I tested this theory out when I got home by throwing on another wheel that was laced up with a non-silent hub. To say that it was a night and day difference would be an understatement. I immediately felt more in tune with my bike, and even though I hadn’t had any problems riding my trails with the silent hub, I did notice that I felt better riding them having audible and mechanical feedback coming from my wheel once again.

So now that I’ve gotten all of the stuff out of the way about what it was like riding the Onyx hub, I have to go back and elaborate on what I said earlier about people having a hard time hearing me when I was riding. It turned out that it wasn’t just at my trails. People brought it up at pretty much every spot that I went to. It made for some seriously close calls both with people walking around the trails and even with people I was following through them. There would be times where I would be following someone and they would straight up forget I was behind them because they couldn’t hear me. Not a big deal until the times where they had to stop mid-line for one reason or another and wouldn’t think to immediately get out of the way because I was behind them. Like I said, it made for quite a few close calls but luckily there were no major collisions.

I feel bad that the majority of the things I’ve had to say so far about the Onyx hub have been negative, but I think that they’re only negatives when it comes to riding trails with it. Everything else about the hub really is amazing. The machining and build quality are top notch, and I can say without any hesitation that the combination of the ceramic bearings and the drag free characteristics of the sprag clutch ensure that this hub is absolutely the fastest/best spinning hub that you can buy. Onyx was actually the first company to successfully manufacturer a hub that utilizes a sprag clutch. That’s due to the extremely precise tolerances that’s required for the mechanism to work properly.

Since they control almost every aspect of their manufacturing, Onyx is able to offer their customers literally hundreds of different hub configurations. The hub that I was riding was their mid-range Ultra hub (msrp $449.99), but they also offer a lower priced Pro hub ($399.99) and higher priced Ultra SS hub ($474.99). The main differences between them is the number of sprag clutches in each of them. The more sprag clutches that they have, the more torque they can handle. All of their hubs are available in a rainbow of anodized and powder coated colors, and customers can further customize them by choosing whatever color combination of hub shell, widgets, and hardware they would like. Up until somewhat recently Onyx’s hubs were only available with a Shimano cog compatible cassette body. This meant that a 12t cog was the smallest you could run on it. They now offer their Pro hub with a 9t driver option for people not looking to run a dessert plate sized gear up front.

Even though I wasn’t a fan of Onyx’s hubs for riding trails, I am a fan of them for other applications. Onyx makes hubs for pretty much every possible cycling genre out there. Though you won’t see me running one in the woods anymore, I do have plans of getting a set for my road bike at some point. And you better believe that if the BMX racing bug ever bites me again, these are the hubs that I’ll be rolling on!

Onyx is currently in the process of launching a new website that will allow customers to easily customize and order their hubs. Until then you can get a hold of them by phone (800-328-8896) or by email ([email protected]). You can also visit their FB page and Instagram, both of which they keep updated with photos of all of the crazy color combinations customers come up with.