Carbon fiber MTB wheels have come a long way in the last few years, so much so there are brands offering 2 year, 5 year, and even lifetime crash replacement warranties on their carbon rims. Those are some pretty bold warranties. In fact, the Race Face Next R video shows a car running over the rim and the rider getting a new one under warranty, no questions asked. Starting to sound a bit like an Allstate car insurance advertisement if you ask me.
There is no denying that carbon wheels ride great: they are stiff where you need them, have great acceleration, and are often a bit lighter. These are all benefits that most of us riders want in a wheel set. Companies like ENVE and Crank Brothers engineer their carbon for specific types of riding and also to be stiff where needed and compliant when it makes sense. ENVE has made their most recent set of wheels a bit less stiff and included a built-in rim strip that wraps around the rim to the outside to help with impacts from rocks. Crank Brothers have gone a bit further. Not only did they make three different models for XC/trail, enduro, and DH applications, but they also tuned the front and rear rims independently for the best possible performance. The front rim is now more compliant, takes a few hits better, improves traction, and maximizes grip. In contrast, the rear rim is stiffer, has better stability, and does a better job of taking the hard impacts that rear wheels often take. Carbon wheels are no doubt a great riding upgrade!
So with all of these awesome benefits in mind, why don’t we typically ride carbon wheels? On a four-day trip to Mammoth mountain, the shop’s owner Jeff took up his newly built Intense Carbine 29 with a set of new carbon rims. On day one he managed to smash a rock and break his rear rim. While he said it was rider error on a bad line, he still had a broken rim at the beginning of a long weekend trip. Even if the wheel he was on had a replacement warranty, he was still out of his bike on a ruined vacation. If he was on an aluminum rim, he most likely would have flatted and dented his rim. For sure a bummer, but with some pliers and some careful tweaking, you can usually continue to ride a dented rim, and often still get it set up tubeless. That right there is why we choose aluminum. You are able to ride through some rim issues on aluminum while carbon is down for the count.
I too have a similar story, except I was on aluminum rims. During a practice run for a race, I tried to get over some rocks and ended up getting two massive dents in my rims. One was so bad it pinched the tire bead in and I could barely get it out. After an hour of work, I was able to pull out the dents, re-tape and set up tubeless so that I was good for my race the next day. A carbon rim most likely would have left me looking for a loaner wheel…
So are carbon rims right for you? If you are a rider who has never dented an aluminum rim before, you take careful lines, and never really have any major wheel issues, carbon wheels might be one of the best upgrades to get to your bike. However, if you often dent aluminum rims, bend or flat spot wheels, and take fast lines where your bike might make some noise, then sticking to aluminum is perhaps a better option. Aluminum wheels like the Industry 9 Enduro 305s are a great choice since you get a very stiff aluminum wheel package with incredible hubs and the reliability of the aluminum rim. Now that we’ve presented our opinion, I hope it's clear that we do not think carbon rims and wheels are a bad choice, just maybe not the right choice for every rider.