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Project321 Launching Ultra-Fast Gravel Hubs

prototype gravel hubs from project 321
13 Comments

Having just rebooted the brand with new mountain bike hubs, Project321 was showing off a slightly quieter version for gravel bikes at the 2024 Sea Otter Classic.

As Lightning McQueen learned, sometimes you need to go slow to go fast, and that’s the thinking behind the gravel hubs. Project321 has trimmed back the number of pawls inside the hub, which slows down the engagement slightly but makes it quieter and infinitesimally reduces drag.

internal ratchet ring and pawl details on prototype gravel hubs from project 321

The big difference between the mountain bike hubs, which have eight pawls working in pairs of two, is the halving of of the pawls to four. This increases the engagement from 1.25º for the MTB hubs to 2.55º for gravel, with an effective 144 points of engagement.

Two pawls remain engaged at all time, with the other two phased by half a step to engage next. That’s still really quick, especially for gravel (or road) where you’re maintaining a constant cadence. The pawls are magnetically pulled into engagement, so there are no small springs that can pop out during servicing.

closeup details of prototype gravel hubs from project 321

The hubs place two double-row bearings at the edges of the freehub body, typically the point experiencing the highest torque and sheer forces.

brake rotor mounting adapters for prototype gravel hubs from project 321

They use their same 6-Lock rotor rings, letting you run 6-bolt or Center Lock rotors on the same hub. They’re natively Center Lock, but use a lock-ring style attachment to fix 6-bolt rotors to them. Launch date and pricing TBA.

Project321.com

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13 Comments
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blahblahblah
blahblahblah
29 days ago

this is just another form of noise pollution society needs to stop

Alan
Alan
28 days ago
Reply to  blahblahblah

My two previous sets of p321 hubs are relatively quiet. It’s one of the things I love about them.

seraph
28 days ago
Reply to  Alan

Quiet? I think you’re confusing P321 for some other company. They’re notoriously loud.

Alan
Alan
28 days ago
Reply to  seraph

Mine are the quiet option and they are not loud. I can’t speak to the non-quiet version.

Oliver
Oliver
29 days ago

Assuming these are insanely heavy … as no weights listed here or for the hubs on their website.

Smokestack
Smokestack
28 days ago
Reply to  Oliver

Front: 155 g (Centerlock) / 175 g (w/ 6-Lock)
Rear: 292 g (Centerlock) / 312 g (w/ 6-Lock)

From a review of the MTB hubs. So, not feathers, not tanks. Google can be your friend at times.

Andreas
Andreas
28 days ago
Reply to  Smokestack

but that was MTB and this is gravel right? implies those are not the weights

Grillis
Grillis
28 days ago
Reply to  Andreas

The hubs are largely identical, just with fewer pawls. I would say its safe to assume they are probably a little lighter than those weights, if not the same.

Mark
28 days ago
Reply to  Grillis

At the risk of repeating myself above:

…we’ve put the hubs on a diet. The front hubs is a completely different hub than the G3 MTB, and shares no parts in common. The rear is a lighter redesigned shell, that shares the same internals as a G3 142mm hub, and that’s a good thing as that hub architecture has been well proven over the last two years in the Stan’s M-Pulse hubs.

And yes, we have removed 4 pawls. If a rider would like to add them back, that will be an option.

Eugene C
Eugene C
28 days ago
Reply to  Oliver

As they are still prototyping, weights for the road/gravel hubs aren’t finalized. It should be in the ballpark of DT 240 hubs, maybe a slightly heavier.

Mark
28 days ago
Reply to  Oliver

Hi Oliver, Mark here from Project321. These hubs are prototypes. Our goal with these hubs is to hit ~350g for the set (excluding 6-lock assemblies). These prototypes currently sit at a little under 360g. That’s pretty competitive with our closest competitors and many popular road and gravel hubs – as Eugene has noted below. Our aim was to hit a lower weight than the G3 MTB hubs, but keep the same super low drag magnetic engagement, robust bearing and axle layout (we’re confident in this to the point we offer a 10 year warranty on rear axles), and seal system. So far, we’re pretty happy with where we have landed on these and we’re testing them now.

Grillis, as noted above we’ve put the hubs on a diet. The front hubs is a completely different hub than the G3 MTB, and shares no parts in common. The rear is a lighter redesigned shell, that shares the same internals as a G3 142mm hub, and that’s a good thing as that hub architecture has been well proven over the last two years in the Stan’s M-Pulse hubs.

Keith Giglio
Keith Giglio
28 days ago

If you want super fast hubs, Onyx Racing hubs with a Sprague clutch and coated ceramic bearings are the best option available.

Rim Brake enjoyer
Rim Brake enjoyer
28 days ago

Great but I need some chip seal with some occasional tar snake specific hubs for my bespoke riding.

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