Teravail Circos Wheels Review: Invisible

Wheel reviews are a hard thing to pen. Though the complexities of what keeps us rolling are seemingly infinite, out-of-the-box offerings should fall into one of two camps: functional or not. Particularly as people who aren’t too concerned with aerodynamics, drag coefficients, and ultra-lightweight designs, wheels should largely disappear and simply function as intended.

Early last year, I received a set of Teravail Circos carbon gravel wheels. I plucked them out of the box, marveled at their sleek, slender profile, quickly wrapped them in a set of tires, and got on with my scheduled bike reviews. Across thousands of miles, a few bikepacking trips, plenty of experimentation on Pisgah’s rough terrain, and countless daily miles, the Circos wheels did, in fact, disappear beneath me. No popped spokes, no cracks, no true-ing. They just work. In my long-term review of the Teravail Circos carbon gravel wheels, I dive into the specifics of this otherwise invisible set of hoops.

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Following the quiet sunsetting of Whisky Parts Co., QBP launched the Circos carbon gravel wheels under the Teravail brand early last year. Optimized for their new gravel tires, like the Updraft, the Circos carbon wheels are a newer offering aimed at riders looking to bridge the gap between light and more extreme gravel riding. With an ASTM rating of 3, the wheels have a claimed weight of 855 grams for the rear and 765 for the front. They use DT Swiss 350 hubs, have a 25mm internal width, feature a hookless design, external spoke nipples, a shallow rim profile, and are available in both 24- and 28-hole options.

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The specs provided make them consistent, if not undergunned, when compared to other options on the gravel market. I’ll get into how they performed at the larger end of the tire spectrum, but it’s worth noting that carbon options like the HED Lancaster G25, e*thirteen Piedmont Race, and HUNT 40 Limitless Gravel Adventure wheelsets all have a wider internal diameter. It’s not the end-all of a wheelset, but a wider internal width would have been nice, as it allows better performance with wider tires. Teravail states the Circos rims will work with tires from 28-55mm, and I spent most of my time with a set of 700c x 55mm Rene Herse Fleecer Ridge tires, which are at the upper end of the width that these rims support.

In Use

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When they were announced, commenters pointed out the lack of higher-spoke-count rims. With the general rule of thumb being that a higher spoke count equates to a stronger overall system, it makes sense that folks who largely ride loaded or on harsher terrain point out the lack of options with more than 28 spoke holes. I’m 5’9” and weigh around 175 pounds, and I’ve made quite a few mentions of my inability to keep aluminum wheels true, particularly after moving to western North Carolina, where the terrain is steep, rocky, and ever-changing. Although I can understand the concern, I have yet to experience any issues whatsoever with these wheels in their 28-hole configuration. Out of the box, already taped and ready to roll, I haven’t had to adjust them, change spokes, or care for them outside of the occasional cleaning. The decision to include the ever-reliable DT Swiss 350 hubs and their Competition spokes adds significant value, as the hubs have been entirely without issue during my testing period.

Aside from my hamfisted bashing through the rocky singletrack we have in abundance, the American Southeast is exceptionally wet. While testing the Fairlight Secan last fall, I got stuck in more mid-afternoon rain showers than I could stand. Throughout the year, they accompanied me on a variety of shoulder-season overnighters and were exposed to the excessive moisture that accumulates on the bike at any campsite. With alloy spoke nipples and steel spokes, I wouldn’t have been too upset if there had been some rust or corrosion, given the sheer amount of moisture they’ve been exposed to. And yet, after two races, a few bikepacking ventures, and tons of miles, there’s no sign of corrosion, and they’ve continued to roll as if they were completely new. The hubs are in great order after all my use, and even though the points of engagement could be improved for single-speeding, it has proven sufficient 99% of the time.

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Another element that readers flagged at release was the use of technical marketing speak. With a 30mm rim depth, they said: “The Circos’ 30mm depth minimizes the moment of inertia, resulting in quick accelerations,” an overly complex way of highlighting the greater rim depth. In my experience with both deeper and shallower rims, I found the 30mm depth to be a solid middle ground. It doesn’t produce sketchy handling moments in high winds like on the 40mm wheels I have from HUNT, but it does feel ever so slightly faster in both acceleration and sustained, straight efforts than a standard option without any depth. Furthermore, at 30mm, you don’t need overly long valve stems, as the standard length should work fine.

Generally, the wheels aren’t overly harsh, and after contrasting them with other 29” and 27.5” alloy models, the speed at which the carbon wheels accelerate is noticeably faster. I’m also confident in saying these provide a palpable difference in decreasing buzz from whatever surface you’re riding on. All in all, they’re less harsh than other carbon options I’ve tried with deeper rim widths without feeling too burly.

One aspect that isn’t just marketing jargon is Teravail’s lifetime warranty and that “All Circos wheels are hand-laced, trued, and tensioned in Minnesota by professional wheel builders.” Given just how well the wheels have held up to all the rough mileage I’ve put them through, it’s clear the build quality is up to scratch.

Tire Testing and Hookless

At 25mm, the Circos wheels are sufficient if not slightly lacking in the internal width department. As I noted above, a few other options on the market feature internal widths ranging from 26 to 30mm, which allow better compatibility and performance with wider tires. It’s a nuanced discussion, as not all internal rim widths are created equal, but it’s worth noting if you have a gravel bike capable of sporting tires larger than 2.25.” The Circos rims measured out to a true 25mm internal width, and they played very nicely with the 55mm Rene Herse Fleecer Ridge tires I’ve used for most of my test period. The tires measure out to slightly under their stated width at 53mm, but there is no odd “light-bulb” effect with these rims. Mounted on the Circos rims, the tires are solid, reliable, and perform as expected.

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Without delving too deeply into tin-foil-hat territory, skeptics of hookless designs have made their feelings clear in recent years. As far as I understand it, the dynamic is as follows. Hookless designs enable a simpler manufacturing process by streamlining the design of the steel molds used to produce carbon wheels. By removing the structure that allows for a hooked system, two goals are achieved. First, because the carbon structure isn’t contorting around the traditional curvature of a hooked design, the rim should be stronger. Second, because there’s less material complexity in the manufacturing process, those savings are theoretically passed on to the customer. In theory, of course.

Hookless critics suggest this is simply a marketing justification for companies to justify a higher margin. Several high-profile failures of hookless systems in professional road races haven’t helped the cause, and companies like SRAM have filed patents for miniature “hooked” systems after said failures. Granted, those more familiar with the engineering realities suggest the worst thing for hookless designs is high pressure, such as that found in road tires. In my year with the hookless wheels, I ran most tires at around 23-25 PSI and never had any issues with burping or unseating. I tested four additional sets of tires with this wheelset—two from Teravail, one from Vittoria, and one from Continental—and all of them went on without a problem. The same rim tape that came installed is still going strong.

Final Thoughts

Though the internal width leaves something to be desired, the $1,460 price of the Circos wheels makes them a standout option among others in the same space. It’s hard to pin down exactly where they fit, as some gravel wheels use slightly older standards, like 15 x 100mm front axle spacing, instead of 12 x 100mm. Sometimes, options with higher spoke counts opt for Boost hubs, while other models with far fewer spoke holes but wider internal widths are geared toward racers. In that sense, the Circos wheels feel appropriately middle-of-the-road. Not exactly a race wheel, but also not delving toward mountain bikes or ATBs either.

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Though some may wish for more spoke holes or better compatibility with wider tires, the Circos wheels are a lot like their intended category. Gravel bridges the gap between road and mountain bikes, and these wheels do the same. As someone who has primarily ridden gravel bikes over the last six years, they feel almost exactly right for any bike in this space. Save for the lack of a 650B option, the approachable, ready-to-roll nature of the Circos wheels feels like a good start for anyone seeking their first set of carbon wheels.

• Model Tested: Teravail Circos wheels, 28h, Shimano HG
• Actual Weight: 678 grams (F), 828 grams (R)
• Place of Manufacture: Taiwan
• Price: $1460 at Teravail

Further Reading

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