Tested: Stan’s Flow CB7 Rims | $600 (rim only)
Don’t you love it when things just work?
29mm inner width
Flat rim profile
Outstanding ride qualities
Good strength to weight ratio
Rides its best at normal trail speeds
Easy to build as rim-only option
No lifetime warranty that some other carbon wheels come with
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A proprietary eponym is a product that becomes so successful that its name is used to describe the generic alternatives, examples being things like Kleenex or Band-Aid. In the bike world, classic examples of this phenomenon might be GripShift or Slime sealant, although the latter has since been eclipsed by an even more successful name—Stan’s. Stan’s sealant and tubeless technology revolutionized modern mountain biking, and it’s become one of the very few proprietary eponyms in the contemporary riding scene. Of course the success of, Stan’s isn’t limited to just slimy white stuff. The company’s rims and wheelsets have long been some of the best bang-for-buck aftermarket options out there.
Part of what has made Stan’s wheels so successful is the fact that they simply work and don’t require any fuss. They ride well and are reasonably priced, and since they’re made by the brand that is basically responsible for modern tubeless systems, you can trust that they’ll lock a bead like a dream.
Of course, I’ve been talking about Stan’s alloy offerings—the carbon Flow CB7 rim is the first version of Stan’s trail rim, the Flow, that’s offered in the fancy plastic. When it was originally released back in late 2019, I was a bit surprised. This is just my personal opinion, but Stan’s had a good thing going with its alloy-centric approach to its heaviest hitting rim—the alloy Flow MK3 was, despite its widespread success, still somewhat of a rebel in a world of wheels that was shifting toward carbon dominance. Sure, the EWS scene might have been swinging the pendulum back towards alloy in some regards, but as far as industry sales reps and Dream Builds went, carbon was king.
And so enter the CB7, a carbon wheelset from Stan’s. I thought, “Great, another wheel to lump in with the rest of pricey carbon stuff that’s entirely unaffordable to the average rider and barely offers any performance gains to boot.” Well, guess what, I was wrong.
Well, sort of wrong. First off, the CB7 is expensive, even for a carbon wheel. At $600 for rim-only and $1,400 for a wheelset, there are other high-end trail/enduro carbon options out there for less. So, why would one choose the Flow CB7 over, well, any of the myriad of opinions out there?
In short, you’d choose the Flow CB7s for a reason we already covered—they just work. In my book, the most important criteria to judge a rim on is ride quality, followed closely by strength. Basically, is it a noodle? Does it break if I case a jump? Will I lose my fillings while riding it through a rock garden? In the past, you got to pick two (or even just one) of those options. But the Flow CB7 is darn near the perfect balance of stiffness and compliance. The CB7s are nice and firm laterally, although feeling closer to some alloy options than typical carbon rims. The last carbon rims I tested were the NOBL TR37s, which are absolute bruisers of wheels. The TR37s were stoic palace guards to the trail’s heckling chatter, whereas the CB7s are good-natured jokers that can bend the rules to keep things from getting too far out of hand. Pushing the CB7s hard won’t see you buzzing tires to chainstays, but I also never felt like I was getting pinballed through rocks. There’s a firm but willing give to the rims laterally that really helps smooth out the wheels’ tracking and let them snake around hits rather than Rambo their way through.
That being said, Stan’s was pretty accurate when they labeled the CB7s “trail riding” wheels. Where the alloy Flow MK3 and now MK4 are common sights on enduro tracks, I’m not entirely sold on putting the CB7s between the tape. The rims are quite compliant and ride smoothly, but they do so best at trail speed, not race speed. Compared, again, to the NOBL TR37, which feel their best when pushing terminal velicity, the sweet spot for the CB7, as far as ride quality goes, seems to be at a quick, but enjoyable pace. Some carbon rims need to be pushed to feel at their best, where the CB7 feels just right at the pace where most of us spend 95-percent of our casual riding time.
At 455 grams for the 29er option, a single CB7 is decently light for its class—around 70 grams lighter than the Flow MK3 or MK4 alloy options. Rotational weight in the wheels is the most noticeable weight on the bike, and a combined 140 grams (two wheels) is definitely noticeable. Is it worth the price of carbon over alloy? Maybe, maybe not. On occasional, hour-long post-work rides? Probably not. On all-day epics? Yeah, I’d shell out the cash for carbon.
If you are going to pick up carbon hoops, you want to know they’ll last. I’ve toasted one rim this year already, and it wasn’t the CB7. Originally, the rims you see here came laced as a full wheelset from Stan’s, but after six months and two rear hub rebuilds (Stan’s has since significantly upgraded the hubs used with the CB7 rims) I decided to relace these rims to my own hubs to finish out the test. A bit of a pain, but it’s a great and rare feeling when the universe has the courtesy to give you one wheelset with a dead hub and another wheelset with a dead rim. Usually, when I unlace my used rims I get things that don’t always look like rims. However, the CB7s were dead straight and round, and barely needed any touch-ups between rounds of tensioning (and haven’t needed to be re-tensioned since the build). It’s pretty neat to build up used rims and have the feeling of building new rims.
This is great place to segue into the CB7’s asymmetric design. The spoke holes are placed 4mm off-center, which allows for more even spoke tension because the spoke holes are sitting more central to the hub flanges. This effectively makes the rim behave more similarly left to right as far as stiffness goes, as well as allowing for better vertical compliance as the spokes are at more of an angle. Does that all really matter on the trail? Well, judging by how smooth, yet firm, the CB7 rides, I’d wager the asymmetric design really does make a difference.
Another thing that might make a difference to you, reader and potential customer, is that Stan’s offers a seven-year warranty and lifetime 50-percent crash replacement discount on the Flow CB7. In reality, seven years is a long time on a rim, and if your CB7 is defective (which is what the warranty covers), you’ll probably find out in that time. However, that and the crash replacement benefits fall short of what some other companies are offering for high-end carbon hoops. That doesn’t mean Stan’s will never consider a rock strike grounds for warranty replcement, but they certainly don’t state that they will. I Should it be a deal-breaker? No, but if you are a wheel breaker and/or rim smasher, you might keep it in mind.
Of course, I couldn’t review a Stan’s rim without talking about tubeless setup, which is big part of this rim’s design. The asymmetric design means the spoke holes are, as you might guess, asymmetric, which leads to a unique profile of the rim internally. The problem with this, traditionally, is that tires have (1) trouble seating and (2) aren’t as secure on one side of the bead, making the system more likely to roll or burp on that one side. The CB7’s profile seeks to address these issues. Though it’s difficult to tell, surfaces where the bead actually seals on the rim are, in fact symmetrical. The off-center depression that makes tire installation possible butts up immediately against the seating surface on one side and ramps up gently to it on the other. It makes for easier inflation and, once seated, a fit just like any traditional rim.
I’ve tried everything from a 2.3 thru a 2.6-inch tire with great results as far as casing shape goes, and surprisingly, I haven’t burped any tires in testing (which is pretty rare for me). Even better, I have yet to find a tire that is difficult to put on the CB7 and every tire I’ve tried has been able to be inflated first try without even removing the valve core. Honestly, that’s the best tubeless experience I’ve had with any rim, and I used to change and inflate tires for a living.
So, where does that all leave us with the Stan’s CB7 rims? Simply put, these are the rims I’ve put on my personal trail bike and plan to keep there for the foreseeable future. As a do-it-all, build-and-forget rim, I can’t really find any fault with the Flow CB7 (except maybe its carbon-appropriate price tag). They aren’t heavy-hitting enduro wheels, but nor are they lightweight hoops for your XC whip. They have the strength and gusto to charge chunder on your average all-day epic and a touch soft enough not to screw over your hands on a big day on the bike. The Flow CB7 name probably won’t ever become a proprietary eponym, but dang, I wouldn’t be surprised if the Wikipedia page for “mountain bike” had a picture of a bike with a Stan’s wheelset someday.