NOX XCR 29 WheelsCarbon at the moment seems to the be the ultimate material when it comes to rims. It’s extremely light, can be made incredibly strong, but it’s also nowhere near as easy to manufacture as an aluminum rim. Founded in 2012, NOX Composites is fairly new on the carbon scene but they bring a wealth of engineering experience to the table with the company founded by two engineers who also happen to race bikes. With a firm belief in wide, offset rim design and offering the performance of carbon wheels at a more attainable price point, NOX set out to reinvent the carbon wheel.

NOX Composites 29 Carbon Wheel NOX XCR 29 Rim

Ok, they didn’t really reinvent the wheel, but they have put a lot of effort into making a wheel that they feel is superior. The rim starts with their own proprietary design, layup, and a controlled manufacturing process. Built mostly from Toray unidirectional prepreg carbon fiber, the rim is supplemented with 3K weave in places of high stress, around drilling holes, and to reinforce the lip of the rim to protect it from square edged impacts out on the trail.

As of now, NOX offers the XCR-29 wheelset and will have an AM-275 wheelset in the near future. The 30mm external, 23mm internally wide XCR-29 rim weighs in at 385g (+/-10g) and a wheelset weighs 1449g with American Classic hubs or 1594g with Chris King hubs, both with Sapim CX-Ray spokes and DT Swiss Prolock nipples.

The AM-275 rim is wider at 33mm external, and 27mm internal and is a bit burlier at 410g per rim. Wheelset weights are listed at 1475g with American Classic hubs and 1599g with Chris King. XCR-29 wheels are offered in 28 or 32 spoke options while the AM-275 will be 32 spoke only. Both models will eventually be offered in both rim only or complete wheels with all King wheelsets offered in your choice of color for the hub.


A large part of the NOX design is based around the asymmetric rim bed with a 2.4mm offset. The same rim is used for both front and rear by flipping it, and the design results in around a 15% increase in low side spoke tension which results in a more even wheel build for better durability, stiffness, and performance. When used with hubs like the AC 225, NOX is able to get a nearly equal spoke tension on both drive and non drive spoke beds.

All NOX rims are designed to be run tubeless with tensilized polypropylene tape for normal or tubeless ready tires. The rims use a tight bead diameter to ensure a solid seal and reduce burping and eliminate the need for thick tape or rubber rim strips.

Pricing for rim only is set at $449 for the XCR-29 and AM-275, with XCR-29 wheelsets going for $1438 with American Classic hubs, and $1598 with Kings. The AM-275s are available for Fall pre-order only and will retail for $1398 for American Classic equipped wheels and $1598 for the King bling.

We’ve got a pair of the XCR-29s on the way, so stay tuned for a full review!



  1. From their website, rider weight max is 240lb ( which wheel not specified) and there is a crash replacement discount for wheels ($320) and rims ($275). Two year warranty against manufacturing defects.

    Looks nice, good to see more mtb companies here in the south.

  2. Rims have a weight limit of 240lbs. The XCR-29 is tailored toward aggressive XC riding and/or racing, but for lighter riders they are plenty strong for full on AM riding. The AM-275 will be built beefier to handle AM at all weights, but it is still light enough for racing. If customers want it, we’ll make XC and AM versions of each. Just let us know!

    Warranty is 2 years, fully transferrable. Lifetime crash replacement policy.

    We also do custom builds with any spoke/hub combo you want, just shoot us an email, and of course we also sell rims separately.

    Nox Composites

  3. Wow….this is the first company I’ve ever seen that offers 27.5″ & 29″ but no 26″. Maybe I’m out of touch, but aren’t there a lot more people riding high end 26″ AM bikes than 27.5″ bikes. Maybe 26″ really is going to die.

  4. But I am glad to see hopefully high quality US made carbon rims showing up on the market at more affordable prices, they are half the price of the comparable Enve rims.

  5. I guess I assumed they were based on the “Straight From Tennessee” in the title. Their website says “Wheels Handbuilt in Tennessee.”

  6. I thought these guys were engineers? Why does their diagram mention higher tensions = stiffer wheel? That’s bullshit. I’d buy more durable, because the equalized tension means the NDS spokes will never be detenionsed enough during unloading events to actually come loose, but the tension of the spoke has nothing to do with wheel stiffness and this has been proven both theoretically and experimentally. More spokes = stiffer. Thicker spokes = stiffer. Wider bracing angles = stiffer. Stiffer rim = stiffer. More spoke tension? No.

  7. Nick is right…increasing spoke tension does not increase wheel stiffness. This is obvious to any trained engineer. However, if you want to see empirical support, you can always Google “Damon Rinard wheel stiffness.”

    And for what it’s worth, I’m a mechanical engineer.

  8. what nick and jasonk missed is that they equalize the tensions. you both should read more carefully. and as an engineer i would hope you could see why.

    by equalizing the tensions you will have a net increase in absolute tensions. not necessary in the drive side but the non-drive side.

    the wheel will be stiffer because the tension in the non-drive side increased.

  9. Dudes, you can totally tell their engineers as their diagram doesn’t even use the same hub to prove their point. Only an engineer would overlook an explanation this simple. Maybe their stiffness math works or maybe it doesn’t, but I would at least like a one to one comparison when putting down “facts” and numbers. Granted, my engineering credentials are limited to the armchair kind so I really don’t know what I am talking about anyways.

  10. @Egen: wheel stiffness is independent of spoke tension, and that includes equalized spoke tensions. Wheel stiffness is primarily a function of spoke stiffness, bracing angle, rim stiffness, and the number of spokes. The only time that tension is a factor is when it’s so low that a spoke completely loses tension as it passes over the contact patch.

  11. Nick and Jason, higher spoke tension does increase the lateral tension component contributed from the spokes as shown in the diagram. However, you are correct that this contribution is small and “in the noise” relative to overall lateral stiffness of a wheel. We suspect the largest contributor to lateral stiffness is the rim itself, followed closely by the spoke system (spoke gauge and number of spokes, not tension), which is why we started designing carbon rims in the first place.

    Damon’s test show that past a certain point, more tension does not add to the stiffness of the wheel system. We completely agree with him (and you) that if you are chasing stiffness, driving up spoke tension is NOT the place to find it. If you check out our website you’ll find that our wheel building philosophy is based off that fact.

    Asymmetrical rims are primarily about equalizing spoke tension which leads to a more durable wheel.

    Nox Composites

  12. By reducing the bracing angle on the non-drive side, aren’t they reducing the lateral stiffness of the wheel? They make the drive and non-drive sides have symmetrical bracing angles, but the way they do it is by matching the laterally strong, more horizontal non-drive spokes angle to the angle of the weaker, more vertical drive side spokes. Smells gimmicky to me, although I am glad they occupy a cheaper price point than Enve.
    Ritchey did the same thing with their OCR (Off Center Rim) in the late 90’s.

  13. Tim, that’s a fair point. Reducing the bracing angle will definitely reduce the lateral stiffness, all else being equal. However, off-center rim drilling equalizes spoke tension without changing the flange spacing. What these guys have done is combine OCR rims with the narrow flange spacing of the American Classic hub to build a dishless rear wheel.

    Lots of people find the idea of a dishless rear wheel quite appealing, perhaps because they have vague ideas about “balance.” I personally don’t see much value in the concept, but I also don’t see a lot of harm. I’m not convinced that small differences in lateral wheel stiffness end up making much difference either way, random internet posters notwithstanding.

  14. I just saw Brad’s post. Brad seems to confuse lateral tension with lateral stiffness. More worrying, the link Brad included asserts the following:

    “Most people assume that higher tension provides higher lateral stiffness. The basic physics behind this theory is sound – more spoke tension does increase lateral stiffness. […] Clearly, the real-world relationship of spoke tension and wheel stiffness is not well understood, and it’s safe to say the relationship is most likely non-linear. ”

    In fact, this relationship is quite well understood; Jobst Brandt articulated it very well. The basic physics behind the higher-tension-equals-stiffer-wheel theory are profoundly un-sound; it requires that we throw out Hooke’s law. I think Brad and Nox are acting in good faith and most likely make a high-quality product, but their grasp of the structural mechanics involved isn’t what it might be.

    Rinard’s test results show a close correlation between theory and the real world. In fact, Rinard’s data show the test wheels getting marginally *stiffer* as spoke tension is reduced (but before the spokes go fully slack). Even though Nox’s wheelbuilding page cites Rinard’s work, their understanding of that work seems to be a bit fuzzy.

    To be fair to Brad and Nox, they are absolutely right when they assert that more tension does not increase the stiffness of the wheel. Our only disagreement is about why.

  15. We actually did talk with Bill Mould during the design phase, very nice guy. His work showing how offset rims decrease lateral deflection with laterally applied loads at the hub was surprising and is one reason we wrote the website verbiage the way it is, namely that it seems to contradict Rinard’s results leading to some uncertainty about what’s really going on. Perhaps the difference was the placement of the load, which then begs the question which one is the one a rider feels as “flex”? We aren’t trying to deceive anyone, and we’re big boys, so we can admit a mistake. If the physics behind the wheel building info is wrong, we’ll change it. With that said, we have considered that Hooke’s law is a only a first order approximation and that possibly it is a simplistic view because the stiffness of our rims spreads the load over a larger region. We’ve been around this circle in our own internal debates and we always come back to requiring finite element analysis to get a real appreciation of the relationships. And then we ask ourselves why bother? No matter what the answer, we aren’t going to change the spoke tension we build to. And no matter what the answer, the fact remains that asymmetric rims improve the equality of spoke tension between NDS and DS and we all agree that’s a good thing. So it’s right about then we say screw it and go for a ride. 🙂


  16. Mavic also tested wheel stiffness. they agreed with Damon, that increased spoke tension does not increase wheel lateral stiffness. also agrees. they did disagree with Damon’s assertion that a rear wheel will be equally stiff to the left as to the right. says a rear wheel is stiffer when pushed to the right. they probably pushed farther…
    rims are very, very likely made in Taiwan or mainland China. which is okay, but better to not dodge the question.
    id go with hubs other than american classics, due to their small left center-to-flange distance. youre just not maximizing the benefits of the offset rim. best to decide on an acceptable minimum left spoke tension, max out the right spoke tension, and then see where the left flange has to be.
    diagrams are not accurate. spokes only go to the top of the flange if theyre built radially, which theyre not. 32, 3x would put the trace close to the axle centerline.

  17. This is an interesting discussion.
    I’ve studied the subject for some years now.

    I’m with JasonK on this. The Nox add is false concerning stiffness. Close flange hubs reduce lateral stifness.
    I talked with Bill Shook, and what i understood was that is design is better for strengh of the whell, because the torsion component on the rim is lower, pushing farther the moment when the whell becomes a taco chips.
    I think this idea is useless with a carbon rim, wich is very rigid and strong in torsion. They do not fail this way.

    I like the assymetrical design but i would go for a classical hub (Like Chris King) on theses rims.

    By the way you got some competition from JPracing1, who will show in val d’isere a pretty similar rim, hookless, made in europe.

  18. @bobS
    The youtube video is intersting and true. I don’t see any contradiction to Rinard’s or Jason’s
    but beware, he compares a symetrical rim to an asymetric on THE SAME hub. Assymetrical is indeed better.

    What Jason and me and others do not agree with, is that an assymetrical rim + a narrow flange hub is more rigid, as statted in the nox add.

  19. Hey, I rode a prototype set of these wheels for about a month. I rode them on my single speed in Knoxville and in Pisgah and I rode them on my full suspension bike in Knoxville and in Pisgah. I probably rode them about 500 miles in a month. I have to say they worked really well. I never burped a tire. They are much, much stiffer than the Arch EX wheels I have with identical hubs (Hope Pro2 Evos) and identical spokes (Sapim CX-Ray). They feel really great when you charge through a whole bunch of rocks and your wheels don’t bend all over the place.

    I also build lots of wheels and in riding them took them off the bike and checked lateral and vertical true and never had to turn a spoke. Using just a Park spoke deflection tool all spokes remained balanced during my test period.

    Also, using the asymmetrical rim seems to only make sense. I really can’t believe that disc mountain rims aren’t all asymmetrical. As for the bracing angle on the disc side being reduced, its being increased by the same amount on the drive side. In the end, I think that having a wheel with tension balanced between the two sides will increase the lifespan of the wheel.

    More importantly than any of that is that they ride really well. Its very difficult to ride bike components on the internet. Your tires will look huge on these wide ass rims. If you come to Knoxville and demo a set you’ll be sad to give them up. I was sad to give them up and so was the other local ripper who tested a set for a month and he rode them more and harder than I did.

  20. I posted an extended reply, but it never showed up. In summary, I agree with Vincent and Greg. The video doesn’t contradict anything I’ve said. Also, the asymmetrical stiffness results at the end of the video jibe perfectly with Rinard’s results. No contradiction there either.

  21. All

    The rims are made in China using Toray Uni and 3K weave fiber. We tried to work with manufacturing partners in the US, but as many of you know there is a lot of labor (~6.5 hours) in each rim and unfortunately we learned we couldn’t make rims of this quality at this price point domestically. Sad but true.

    Vincent, Jason, etc.. thanks for the input, you guys made us run the bracing angles and you are correct, the wheel on the right is less stiff by about 16%. Given this, we agree the ad is misleading – and we will update it to use the same hub on the left and the right. This was an oversight that we should have caught. What we were trying (apparently poorly!) to portray was that asymmetrical rims improve the bracing angles on dished wheels, thereby providing a net increase in lateral stiffness, and a net increase in spoke tension and DS/NDS equality – all good things. In hindsight, we should have just used the same hub left and right side and not unnecessarily changed hubs. We will update it to do just that.

    I’ll also update the website to further explain how a net tension increase improves stiffness because net tensions goes up as bracing angles improve. This has obviously been a point of confusion and needs to be clarified. When we say physics shows that stiffness increases with tension, we of course are talking about net tension increases which come from using an asymmetrical rim and the corresponding improvement of bracing angles, NOT that you can just crank your spokes to 400 kgf and gain lateral stiffness.

    In response to someone saying that spoke tension equalization isn’t needed with a carbon rim, we look at it the other way. Since the rim is by far the largest contributor to stiffness, and our rim is very stiff, then we have “stiffness to spare,” and trading a small amount of stiffness which comes from slightly lower bracing angles on a hub like the AC for the strength and reliability of DS and NDS spoke tension equality might not be a bad idea. Remember from a stiffness point of view, in order of importance it goes 1. Rim 2. Number of Spokes 3. Bracing Angles. An almost 31mm OD carbon rim and 32 spokes gives you some stiffness to play with. I personally can’t feel the “reduction” in stiffness from 0.8 deg loss of bracing angles with an AC hub. But we do know weight is important for a lot of people, and the AC hubs are incredibly light which is why we currently offer it as an option.

    Nox Composites

  22. My i9’s on Stans hoops weigh nearly the same, cost half as much, and have far superior engagement. Carbon is nice but how can the average person justify spending that kind of coin. I’ll own a set when the cost is in line with the performance of the product.

  23. The bottom line that I see with these wheels is that you can purchase a product that is supierior to other carbon offerings in terms of internal rim width and price. Buying one Enve rim alone is upwards of $900+ – One Rim! Comparing Carbon to Alloy is apples and oranges – for real. If you’ve never ridden a Carbon hoop thought single track you need to. The weight savings doensn’t matter nearly as much as the stiffness through corners – especially on 29ers. Plus the impact resistance of carbon is umatchable. If you hit the a carbon hoop hard enough to break it, you likely would have cracked the Alloy counter part also.

  24. Nice response, Brad! It’s always impressive when people respond to criticism in such a constructive way.

    Thanks for clarifying NOX’s take on the spoke tension/lateral stiffness situation. That makes more sense to me now.

    Also, I agree that the slightly lower bracing angles of an AC hub with an offset rim will result in a stiffness reduction so minor that it will be undetectable by riders. People often claim they can feel incredibly subtle differences between setups, but mostly this is the placebo effect. Human beings are terrible data acquisition devices.

    IMHO, Brad’s thoughtful response and his willingness to address honest mistakes in a substantial way speak very well of his company. (That said, these mistakes are quite small and are essentially geeky quibbles). I build my own wheels, but if I didn’t, I’d have no qualms about picking up a set of Nox’s wheels.

What do you think?