Light, durable, reasonably priced – generally, the saying goes, you’ve got to pick two. With the SUNRinglé Black Flag Pro 29er wheelset you get a combination of all three that’s just a small step down from the benchmarks in all of the categories. It's a complete package perfect for the privateer cross-country racer or everyday trail rider.
The Black Flag Pros have proven durable, unlike some of their super-light alloy competition, and the tape-sealed tubeless BST (Bead Socket Technology) rim profile licensed from Stan's NoTubes is relatively wide (21mm, internal), so it works well with larger-volume cross-country tires
SUNRinglé's outer rim profile is slightly taller than Stan’s, which seems to add more stiffness – and likely a bit of weight – to the package. The rim alloy also seems harder than what we’ve had from NoTubes in the past.
The front and rear hubs are compatible across all of the current axle standards, and the set even comes with end-cap adaptors for 9mm quick-release, 15mm and 20mm front axles. The rear wheel comes standard with a 9mm quick-release, but 12mm rear adaptors are sold separately for both 135mm and 142mm through-axle standards. Just about the only thing we aren’t in love with is the color, but they also come in black.
Handling: Light feeling and stable
The Black Flag Pro wheelset isn’t super-light – it weighs roughly 200g more than Stan's alloy Crest 29er – but like the NoTubes wheelset it rides very light, likely due to the weight of the rims and the fact that the BST profile makes it easy to convert non-tubeless tires.
We ran standard tires tubeless, in both 2.2in and 1.9in widths, without problems during the course of our testing and with good results. We raced short tracks on the smaller tires, while we definitely preferred the larger tires on the trail.
The Black Flag Pro 29er wheels held up on the race course against those costing almost twice as much
Along with feeling light, the wheels stayed dead true, and the rims resisted any denting, despite a few bumps off rocks. Stiffness under acceleration was fine, but under cornering we could detect a slight bit of give in the rear wheel. However, this didn't hamper the ride or our ability to make the bike go where we wanted. When comparing them to older, lighter NoTubes 355 wheels, they’re noticeably stiffer.
The reasonably wide inner rim dimension paired with the slightly taller and subsequently stiffer rim profile gave the wheels a good, stable feeling when letting the bike run, especially in a straight line. We did our share of pinballing through rock gardens on the wheels – with the larger tires – without problem. Keep in mind, however, that the whole of our testing was carried out on cross-country bikes at cross-country speeds.
The Black Flag Pro rim uses Stan's NoTubes BST rim profiling
Components & build: True out of the box and after riding
SUNRinglé build the Black Flag Pro wheels with 28 straight-pull, double-butted Wheelsmith spokes and alloy nipples for both front and rear wheels. The spokes are black save for the rather old-school technique of surrounding the valve hole with an off color (in this case white), so that the rider can easily find it for flat repairs out on the trail.
The hubs are Asian made and include ‘premium’ quality Japanese sealed cartridge bearings that felt silky smooth in hand – in fact, smoother than a European-made set we’ve tested congruently. The rear hub runs on four bearings and features a lightly-sealed three-pawl hub. An important note, while the rear hub held up fine in our mostly dry climate testing, others have degraded prematurely in wet environments during our testing. Engagement was solid, but average in terms of its speed.
Sun Ringle's straight pull 'Dirty Flea' hubs sported ultra smooth bearings
The Black Flag Pro package includes all three front hub adaptors, which will likely keep the wheels in your quiver long after you’ve upgraded your bike or fork. We have an especially warm spot for them because we're always swapping parts, and standards, in the name of testing.
We tried the wheel with a 9mm skewer and 15mm axle, with similar forks (i.e. same model, different dropout), and can attest that the through-axle is worth the weight penalty should you be in market for an upgrade – the stiffness increase is tangible.
