Sun Ringle Black Flag Pro 29er Review – Out of the Box

I needed a new wheelset for my Surly Karate Monkey build, so I started looking around at all the high end hubs and rims available. I’ve noticed a lot of Stan’s NoTube rims showing up on bikes, and I even had the opportunity to change a flat tube on a Stan’s Rim. I was really impressed at how tight the seal was, and thought it would make a great tubeless rim. I decided to consult Guitar Ted, the primary writer of the Twenty Nine Inches website, as he’s tested just about all the 29er parts available.

Sun Ringle Black Flag 29er
Out of the Box

I told Guitar Ted about my interest in the Stan’s NoTube Rims, and he recommend I check out the Sun Ringle Black Flag Pro 29er wheelset, the company’s high end offering. Sun Ringle manufacturers the rims for Stan’s, and Stan’s has licensed the NoTubes design for the Black Flag rims. I couldn’t find a whole lot of information on the sealed bearing hubs, but I like the straight pull spoke design (no bend in the spoke where it joins the hub), and the weight of the wheelset was just in the range I was looking for.

Sun Ringle Black Flag 29er
Extras included in the box

I sent Denis at the Bike Habitat an email to see what he thought about the wheels, and when I got back from lunch, he replied that the wheels were on their way! I had originally wanted the black rims with the gold hubs, but these were not currently available. I ended up getting the opposite color, gold rims with the black hubs. As it turns out, they look great with the dark red of the bike frame.

Sun Ringle Black Flag 29er
Standard 6-bolt Disc Mount and Straight Pull Spokes

Here are the Product Specs:

  • Stan’s NoTubes™ BST Technology (w/Rim Tape)
  • 24mm Rim Width
  • Premium, Cartridge Bearing, Straight-Pull Hubs
  • Quick Release, QR15, 20mm Thru-Axle Front Axle Options
  • Quick Release, 135×12, 142×12 Rear Axle Options
  • Wheelsmith Straight-Pull, Double-Butted Spokes, Laced 3-cross
  • Wheelsmith Alloy Nipples
  • 28 / 28 Hole Count
  • Cro-moly Skewers
  • 830 grams front, 940 grams rear, 1770 grams for the set (weighed on my scale without skewers or brake discs)
  • $650 MSRP

Sun Ringle Black Flag 29er
Freewheel Body

What I really like about this wheelset is that it includes everything you need to get it going. Tubeless ready means just that. The rim tape is designed for tubeless installation, two tubeless valve stems are included, and it even comes with enough Stan’s NoTube sealant to complete both wheels. Also included are Sun Ringle chromoly skewers, and adapters to run various axle sizes. I didn’t pop out the axle size converters, since they came setup just the way I wanted; however, you can check out for some good detail photos of how they work.

Sun Ringle Black Flag 29er
Black Flag

Weight for the wheelset came in just a bit higher than advertised, but at 1,770 grams, it’s right on target for similar wheels in this price range. The Black Flags are a full pound lighter than the On One wheelset I had borrowed off another bike, and the rim width is slightly wider too. The rim’s Bead Socket Technology (BST) creates a rim with a shorter sidewall which allows the rim to be lighter, lets you to run lower pressures, and allows the tire to use more of its sidewall and have a larger volume. Much more detail about BST can be found on the Stan’s NoTube site HERE.

Sun Ringle Black Flag 29er

Sun Ringle Black Flag 29er
Licensed by Stan’s NoTubes

Mounting and inflating the tires was a snap. My favorite WTB non-tubeless tires mounted easily on the rims. Before we put the last bit of bead on the rim, we filled the tire with the supplied sealant.  Then we popped the last of the bead onto the rim, and inflated the tire with an air compressor. Both tires sealed up so easy that I suspect a regular hand pump would have worked too. I shook the wheels around to disperse the sealant around the tire, and then mounted the wheels on the bike. Both tires have been holding air extremely well ever since.

Sun Ringle Black Flag 29er
Tubeless Ready Rim Strip

Sun Ringle Black Flag 29er
The finished product installed on the Karate Monkey

The gold wheels look great with the red paint on my bike, and really make the bike look sharp. The next step of course will be to get these wheels tested out on the trail! It will almost be a shame to get these beautiful wheels dirty. Almost… Stay tuned!

12 thoughts on “Sun Ringle Black Flag Pro 29er Review – Out of the Box

    1. Yeah, you just pop out the valve stem and you’re ready to go for a tube. In fact you should always carry a tube even if you’re going tubeless. They can be tricky to inflate with an emergency pocket pump, and the sealant won’t seal up things like sidewall tears.

  1. Thanks for the review. Can’t seem to find much information on them. How does the rear hub sound? Quiet or loud?


    1. I’d say it’s medium. Not loud like a Chris King, but I can’t sneak into the office unless I’m holding the back wheel in the air. My riding buddies may argue, but I don’t think it’s annoying at all out on the trail.

  2. Hi. I couldn’t find a follow up review and was wondering how well this wheelset is holding up for you. I was thinking of throwing a pair on my my rigid vassago,. Looks like a pretty solid wheelset and a nice weight….just not sure how much abuse they will take.

    1. Yeah, I need to get that follow up review going! The wheelset has been great, and I’ve put a lot of miles on it. Very light, and they roll incredibly well. The rear wheel has been trued up once, but the front wheel hasn’t needed it. The rear wheel has a slight creak in it, possibly from the hub. It remained after the wheel was trued, so I’m still not certain what it is. Not too big a deal though, as it seems to come and go. I’m running spacers and a single speed cog, and the freehub body material seems to be holding up ok. I would buy it again.

  3. Thanks for the reply…and for the quick review! I’ve been on the fence between the Black Flag Pro and the Charger Pro, which has a wider rim. My trails consist of quite a bit of rocks and roots, but It sounds like, at less than 180 pounds, I could get the Black Flag, enjoy the lighter weight, and still have a solid wheelset for everyday use. There are some pretty good deal s out there on these wheels.

  4. Did you notice the lines on the freehub body are too small for cogs and it alows the cog to rotate slightly clockwise and counter clockwise

    1. It’s been a while since I’ve had the cog off, but it’s a standard cassette freewheel body. I think the main difference would be the cog itself. I’m using the Surly cog which has a nice wide base on it. It’s supposed to be nicer to your freewheel body than some of the cheaper skinnier cogs. There may be some play when you slip it on, but it seems to snug up against the drive side and wedge itself there. I remember having to tap it a bit to get it off once…it didn’t just slide off.

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