Unboxed & Weighed: Nox Composites’ Wide Carbon Mountain Bike Rims

Nox Composites first came across our screens this summer, offering a lightweight, wide carbon fiber rim that’s designed in Knoxville, TN, at about half the price of competing options. Then we got a set in, threw them on the scale and promptly took them to Asheville, NC, to break ’em in.

Founded by two engineers, Nox’s rims come in two iterations, a wider all-mountain 27.5″ and a lighter (but still plenty wide) XC-ish 29″. Both use asymmetric spoke drillings to allow for equal spoke tension on either side of the wheel. With a claimed rim weight of just 385g for the 29er and 430g for the 27.5″, they’re light for the widths, and promise to be very, very stiff. Since our original post they’ve added Industry Nine and Hope hubs to their complete wheelset offerings, joining American Classic and Chris King. All wheels are now built with CX-Ray spokes and alloy nipples, and all are hand built in their Knoxville facility.

Our test set is the XCR 29 laced to American Classic. So far, they’re living up to the hype – light, stiff and durable. Roll on for detail pics, actual weights and first impressions…

The rims are made primarily with Toray UD fibers, adding in woven carbon in the spoke bed, edges and spoke holes to reinforce high stress and impact prone areas. In particular, the woven carbon at the rim’s edge helps cracks from propagating should you really nail it on a rock.

Spoke holes are offset by 2.4mm, which lets them balance tension on both sides of the wheels and still allow the same rim to be used front or rear. Just flip it over depending on where you’re using it.

They’re tubeless ready, just add tape if you’re getting a rim to build up yourself. Complete wheels will be pre-taped with Stan’s NoTubes yellow tape, which is what we used after photo’ing and weighing them (Nox intentionally sent them to us bare so we could see the construction).

The bead hook isn’t the shortest we’ve seen, but it’s short enough that you don’t need to build it up with tape to get the tire’s hook to sit tight. A mid-depth center channel makes getting tires on the rim a bit easier, then the bead platforms angle downward ever so slightly to help them slide into place. Whether that last bit was intentional or not, our Kenda Honey Badgers mounted without any trouble.

Decals at the valve hole show which side the disc rotor should be on, making builds easier.

American Classic’s hubs have proven themselves durable on several other test wheels we’ve had in (here and here, for instance) under riders both lighter and heavier than me, so I suspect they’ll provide a great platform for this test, too. Ours came ready for thru-axles front and rear, and both are drilled for and laced with 32 spokes. 28 hole is also an option from Nox.

Wheel weights without rim tape are 667g (front) and 789g (rear). That’s just 1,456g for a 29er wheelset. With a 240lb rider weight limit. And a two year warranty.

Other bits in the box include American Classic’s valve stems (7g), brake rotor reinforcement rings (10g) and QR axle adapters (75g). I didn’t weigh the rim tape, but you could go light on the chamois cream and make up that difference.

Claimed widths are 30mm outside/23mm inside/25mm depth. Ours measured in at just over 31mm wide and 24mm inside. That made the already monstrous Honey Badger look positively menacing. It didn’t care.

FIRST IMPRESSIONS

On the trail, they look simply bad ass. Particularly on the murdered out RIP9 RDO. The finish is a satin black, and I suspect those decals would come off without much of a fight (though they’re not peeling or anything). They even looked good on the stand, where they came out of the box as true as I’ve ever seen any wheel. Ever. Looks are important, but it’s the ride that matters.

The XCR 29 wheels are designed to be “durable enough to ride everyday, but light enough to race.” They’re certainly light enough, though some of that’s hidden when you throw 800+ gram tires on there. So the first part of our test is to see if they are indeed durable enough for frequent abuse. With that in mind, we kicked things off in Asheville and tried to hit every rock, root and drop we could. And there’ll be more of that to come. So far, there’s no sign of damage.

When I wasn’t aiming squarely for things I should have been trying to avoid, I’d try to whip the wheels hard into a corner. I expect a carbon rim, especially one this wide, to be stiff, and it was. Alloy wheels at this weight have never felt sturdy enough for big boys like me (6’2″ and 185lbs…without kit), but these wheels do. Even better, there wasn’t any of the creaking or popping normally heard when a new wheelset is broken in.

First impressions are really good. They’re within 7g of claimed weight while sitting a bit wider than spec’d. I’m very much looking forward to swapping to some lighter weight (as in, half the weight) XC tires and throwing the wheels on the racier Jet9 for more testing. But not before a little more punishment on the big bike this weekend.

NoxComposites.com