Curve Dirt Hoops Review: Chunky and Smooth

When Melbourne, Australia’s Curve Cycling released its Dirt Hoops last year, it was refreshing to see a wheelset lineup marketed for “off-road” use rather than some pseudo-specific genre, such as DownTrail, or GravGravPlus. As Curve puts it, Dirt Hoops are for “MTB, Gravel, Off-Road Touring Adventures, Mega Expeditions, Bike Packing, Basket Packing, Beard Packing – Whatever spins your wheels.” It was that snub to industry taxonomies that made me give the Dirt Hoops wheelset a second look among the menagerie of carbon options currently on the market. And after digging deeper, I’ve found there’s even more to like about them.

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For starters, Dirt Hoops are configurable to suit almost all the popular styles of dirt-focused adventure cycling. They’re available in 27.5 and 29” diameters and two different rim widths: Wide 35 or Wider 40. The Wide 35 is named for its external rim width and measures 25mm from bead to bead on the interior, a versatile size that’s suitable for gravel and XC mountain bike tires ranging from 42mm to 2.3” (58mm) with a sweet spot at about 2.1”. The Wider 40 has a 30mm internal width, which is equally adaptable for the range of dirt tires measuring between 2.25” to 2.8”, with a sweet spot at around 2.5”. Curve specs the Dirt Hoops with the reliable and relatively quiet DT350 hubs, or you can opt for DT240 hubs if you wish. Both are available with a 12 x 100 or 15 x 110mm thru-axle up front, and a 12 x 142 or 12 x 148mm rear with your choice of freehub driver standard—Shimano HG, Microspline, or SRAM XD. In addition, Curve includes an extra pair of spokes and some nice wheel covers. I opted for the 29” Wide 35 with 142 x 12 and 100 x 12mm DT350 hubs and an XD driver. These would be perfect for my Kona Sutra LTD with fast, ~2.1” dirt-touring tires.

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Carbon Wheels for Everyone

You might know Curve Cycling by way of their lauded GMX bikepacking rig or their ultra-wide Walmer Bars. But before they made bikes, wheels were the company’s bread and butter. In fact, Curve has been building carbon wheels since 2012. Even so, Dirt Hoops are Curve’s first proprietary carbon rim. Prior to this design, Curve used open mold rims for their wheelsets. That essentially means their older G2 rims were manufactured at factories that offered the same rims to other wheelbuilders for rebranding and resale, which isn’t necessarily a bad thing. There are plenty of great open mold rims available, and many wheelbuilders choose to import factory-direct open mold designs in order to maintain a relatively low cost. And while Curve claims that they worked closely with their manufacturers and engineers to help evolve some of those older designs, Dirt Hoops rims were designed from the ground up for Curve, and in direct collaboration with Curve, specifically for the type of riding that they are interested in—ultra-long rides on dirt.

Well Tested

That last sentiment takes on a new meaning when you look at the riders that head up the company. Having ultra-endurance athlete Jesse Carlsson and Race to the Rock legend Sarah Hammond at Curve’s helm says a lot. And there’s no doubt that these two place a priority on real-world testing, much of which comes in the form of massive bikepacking trips. When testing the new Dirt Hoops, Jesse and Sarah spent six months in the Australian Outback planning the 2019 Race to the Rock route. Jesse then went on to race it with those same wheels. They were further tested on the Lesotho Expedition across South Africa and into the mountain kingdom of Lesotho. Then later that year, Jesse, Sarah, and Curve sales director Ryan Flinn rode these wheelsets through Namibia to finalize a race route for The Rhino Run. All in all, Curve claims they put in six months with somewhere between 20,000-30,000 kilometers on the pre-production Dirt Hoops before bringing them to market.

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Curve’s commitment to durability and reliability also carried over into the components used in this wheelset. Aside from speccing them with trusted DT350 hubs, Dirt Hoops are built with 28 Sapim CX-Ray Aero Bladed, straight pull spokes, which thread directly into hub flanges, a system that’s touted to be stronger than a J-bend spoke interface. While some may argue that point, I’ve yet to break a spoke or have any issues with them going out of true. I’ve now put well over 1,500 miles on this set, half of which was on fairly heavily loaded bikepacking trips. And much of that was through Colombia’s páramos, a region that’s full of very rough and rocky dirt roads, and incredibly long and rugged descents. For what it’s worth, two other members of our group broke spokes. It’s also worth noting that the Dirt Hoops are designed to use only two spoke lengths throughout the wheelset, which makes carrying spares relatively simple.

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Breaking the Mold

So, what makes these rims special? Dirt Hoops rims are constructed from 3K, unidirectional Toray T700/T800 carbon, which is fairly common for bike rims, but the mold is unique. Specifically, the bead profile and spoke bed were designed with a focus on durability. The most visible evidence can be seen in the rims’ chunky 5mm thick carbon hookless beads. They are rather short, but the stout beads give the wheels a significant foundation that Curve claims is stronger than its previous rim designs. I was a little concerned that they might be too short, but they set up tight and secure, and I never lost or burped air. I also bottomed these rims out on rocks on several occasions with no resulting damage or pinch flats.

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According to Curve, the Dirt Hoops conversation literally started on a napkin at dinner while the team was brainstorming ideas around molded spoke holes and spoke reinforcement. Curve’s engineers then worked with their manufacturer’s engineers to incorporate those ideas into an internal spoke reinforcement that they call “Mo-Spo Tech.” This provides a unique molded spoke hole profile that adds internal material at the spoke holes but reduces the bulk of unnecessary material throughout the rim bed. This results in a lighter rim overall, with more durability at the spokes and no compromise in overall strength, according to Curve.

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Out of the Box, onto the Trail

As noted, I installed the Wide 25 Dirt Hoops on my Kona Sutra LTD. This pair came with tubeless tape and valves and tipped the scales at 1,517 grams out of the box. Curve claims a standalone Wide 35 rim weighs 385g per rim and the Wider 40 rim weighs 440g.

The Dirt Hoops were shod with a pair of 29 x 2.3” Teravail Ehlines. As expected, they set up tubeless quickly and easily without a compressor. I rode the Sutra with these wheels and tires on everything from techy singletrack, to gravel, to the long, bumpy roads of Colombia’s paramos. Having formerly ridden the Sutra with its heavy stock wheels, I immediately noticed the rotational weight savings. The Sutra LTD is an extraordinarily well-balanced bike, and having less weight underfoot only amplified this quality.

In addition, the Sutra’s slightly heavier duty “touring” tubeset isn’t the most compliant frame out there, although it’s not bad. I found that the Dirt Hoops did a pretty good job at absorbing bumps and general chatter, given their rather chunky rim bed. They gave the Sutra a lively feel and made it all the more comfortable. I wouldn’t say they’re the most compliant wheels I’ve tried, but they are very good, and they certainly make a case for a relatively low count of steel spokes on a mixed-terrain bike. The Ehline’s rounded profile also helped in this regard.

My one performance complaint with this wheelset is based on my time riding technical singletrack. The DT Swiss 18T Star Ratchet freehub is great on gravel and pavement, but once you start grinding through technical bits, the pedal engagement lag is pronounced and can be somewhat annoying. Otherwise, it’s nice and quiet on the roads, but I’d still prefer to see Curve spec the 36 or even 54T ratchet with the wheelset out of the box. The company claims you can customize your order with either of those ratchets, but I was unable to find this option on their website.

Lastly, Curve offers a 2-year warranty for the Dirt Hoops wheelset, and a 50% crash replacement guarantee.

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• Rims Available Carbon with 25mm 30mm internal width
• Hubs DT350 Hubs / 28-spoke, straight pull
• Model tested 25mm / 142 x 12mm rear, 100 x 12mm front
• Tested Weight (front) 705 grams (with tape and valve)
• Tested Weight (rear) 812 grams (with tape and valve)
• Price $2,198 AUD (about $1,540 USD)
• Place of Manufacture Rims made in China; Wheels Built in Australia
• Manufacturer’s Details Manufacturer’s Details