Final Review: NOX Composites XCR-29 Carbon Rims

I introduced you to the NOX Composites XCR-29 rims about 3 months ago.  Since that time, I’ve been thrashing these on a regular basis, so click through to see how they stacked up against the marketing claims.

Vanity

Lets be honest: no matter what we say, we all want our bikes to look good.  Aesthetics should not be the biggest deciding factor when buying parts, but when you’re dropping lots of coin on some high end carbon wheels, it’s not unreasonable to want them to look as good as they perform.

Thankfully, the NOX rims look pretty sweet.  They’re wide, deep, and have a matte, raw UD carbon finish.  They look the business.  Like monster truck wheels.  The decals aren’t too flashy, and they can peel off easily if you want to go for the full stealth bomber look.  And since they’re available as a rim only, you can have your favorite wheel builder build you a set with whatever color hubs, spokes, and nipples you want, allowing the wheels to match the rest of your bike.

Hey everyone, come see how good I look!

Out on the Trail

Looks are one thing, but how they ride is what really matters.  Bottom line: these rims are all that and more.  They are super stiff, which means they corner with confidence.  When you’re pushing the bike into a berm, flexible wheels feel vague and unpredictable, because the contact patch is moving relative to your contact points on the bike (bars, pedals, saddle).  With stiff wheels, like these, the tires are always right where you expect them to be.  The same thing happens when rumbling across root and rock gardens or railing off-camber corners.  These rims are rock-solid and confidence-inspiring.

This switchback goes through a ditch, with a steep, rooty exit that requires some momentum to make it out the other side, although maintaining momentum through the turn is tough. The stiff NOX rims make it easier to lean in hard and trust the wheels to carry you through.

The stiffness isn’t the only thing that makes these rims corner so well–the width is another factor.  The NOX rims have a 24mm inner width, whereas most “wide” XC rims are only 21mm, and some are 19mm or narrower. The extra width opens the tire sidewalls up, letting them stand up more vertically and provide better support to the tread.  This results in a more stable tire, more air volume, and lets you run a little less air pressure before the tire starts to feel squirmy.  All of this provides a smoother ride, more grip, and less rolling resistance.

There is a possible downside to wide rims, however: they leave the tire sidewalls a bit more exposed on narrower tires.  Narrow, really light tires and wide rims probably won’t mix well with rocky terrain.  Thankfully, there are plenty of light tires that aren’t too narrow, like the 2.2in wide Maxxis Ikon.  It’s only 520g, has lots of volume for its size, and rolls very fast. There’s really no reason to use a narrower tire.

Low weight obviously makes climbing easier, and it also helps when making moves like this.

The low weight of the NOX XCR-29 rims is obviously a big advantage.  My wheels (Hope Pro 2 Evo hubs, DT Swiss Revolution spokes laced 3-cross, and alloy nipples) weighed in at only 1,580g.  That leaves no excuses on the climbs!  And there are lighter hubs that could be used to drop the weight even further.  The wheels spin up the climbs as easily as a 29er wheelset can, and thanks to the combination of stiffness and low mass, they make accelerating out of corners a blast.  Stomp the pedals just as you start to come out of the lean, and there’s no give or “mush”–they’re just solid and fast.

The tubeless setup has also been rock-solid, with no issues at all.

Since building my own set, I’ve built three other sets for customers, and the rim weights have been a bit higher than my own.  The other six I’ve built were all right at 400g each, about 15g more than the claimed weight.  The ERD measurements have been exactly the same on all 8 rims I’ve built, however.  Even with the slight weight increase, they still build into light wheels.  The latest set I assembled used Industry Nine Torch Classic hubs, and they weighed only 1,565g!

Durability

Durability is a big concern with carbon rims.  The myth that carbon parts are brittle and spontaneously explode still circulates in internet forums and trailhead chatter.  The truth is, properly-made carbon is actually much more durable than aluminum.

I’ve banged the NOX rims on roots and rocks more times than I can count.  At the Black Bear Rampage (a 40 mile race in the mountains of Tennessee) I hit a sharp-edged rock hard enough to bottom out both rims, and the sound from the front impact sounded like something cracking, so I stopped to look over the wheel.  I expected to find a cracked sidewall, or maybe a spoke pulling out, but I found nothing.  Both rims were perfectly fine, and I’ve put several hundred miles on them since then. The wheels are still as good as new… maybe it was the rock that cracked?

I rode the NOX rims on my geared bike a bit too. The swapable endcaps on the Hope hubs make it super easy to switch between a QR axle and thru-axle.

Verdict and Future Offerings

The NOX Composites XCR-29 rims get two big thumbs up from me.  They’re everything you’d want in a carbon rim: wide, light, stiff, and durable–all at a very competitive price of $450 per rim.  When compared to the benchmark 29er rim offerings from ENVE (about $850 per rim), the XCR-29s are only a little heavier than Enve’s XC rim, which sports a very narrow 18mm inner width. The NOX XCR rims sport the same width as Enve’s AM rim, but the NOX rims weigh 45-60g less.

There aren't many companies that make their carbon rims available as a rim only, and as a wheelbuilder I'm stoked that NOX does. As a consumer, you should be stoked too, because it gives you unlimited options in how to get them built. I built this set for a customer in Texas, using a Hope front hub and a DT Swiss 350 rear hub with the upgraded 36T Star Ratchets. Burnt orange nipples were used to match his carbon Turner Czar. That's the beauty of custom - built just for you the way you want.

There’s several ways to get your hands on a set of NOX rims.  You can buy complete wheels direct from NOX with a selection of hub choices, buy just the rims direct from NOX and lace them up yourself, or buy a set of wheels from one of their dealers for even more custom options.

NOX Composites is a young company, and the XCR-29 rims were their first offering. As far as I’m concerned, they hit a home run.  They will have more products available very soon to follow up on the XCR’s success. The AM-275 rims (a super-wide 27.5mm inner width 650B/27.5″ rim aimed at enduro/all mountain riding) will be available any day now, and will be followed by a similar extra-wide enduro 29er rim and a lighter XC-oriented 650B rim.

Be sure to keep an eye on NOX Composites!

Many thanks to NOX Composites for providing the XCR-29 rims for review.

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