Project 321 Hub Teardown AndrewM

Project 321 Hub Teardown

Words Andrew Major
Photos Andrew Major
Date Oct 2, 2017

Project 321

Project 321 is best known as an aftermarket Lefty dealer, a premier Lefty service center and for manufacturing steerer tubes to adapt Cannondale Lefty struts to any mountain bike frame. In the mountain bike realm that is.

The company also machines aftermarket parts for Carroll Shelby International along with their own automotive accessories but a recent relocation from Fresno, California to Bend, Oregon suggests bikes are a lifestyle as much as a business. Who doesn't want to ride out their back door to awesome trails?

Project 321 Hub Teardown AndrewM

I managed to catch up with Jeff Bryson before he jetted off to the last round of the EWS in support of Remi Gauvin and Jesse Melamed of Rocky Mountain Bicycles. 

Project 321 Hub Teardown AndrewM

Beautiful, quiet (or loud), quick engagement, simple to service and thoughtfully designed. 

P321 has been selling hubs, including popular Lefty front hubs, for a long time but their brand new release is entirely designed and manufactured in-house, with the exception of the Japanese made EZO cartridge bearings. 

The company will also be supplying hubs to select rim manufacturers. Tim Coleman is currently testing a set of We Are One carbon wheels using the hubs shown here. By all accounts, the folks at We Are One are particular and there are a number of Gucci hub options they could have chosen. 

Project 321 Hub Teardown AndrewM

The 1.5mm hex key that adjusts bearing tension for the rear hub is spaced such that it can be accessed without removing a rotor - something that can be a PIA with other designs. 

Project 321 Hub Teardown AndrewM

Two sets of very fine threads. The bearing tension adjuster threads one and the 1.5mm set screw contacts in the center. Fine threads mean fine adjustment. 


Every perspective of the Project 321 hubs remind me of something that Pete from North Shore Billet said to me once: "Why machine a straight edge when you can machine a curve?". 

When it comes to configurations the options from P321 are almost endless. Almost every variable in ten different anodized colours is available for shells and axles: Black, Blue, Gold, Green, Pink, Orange, Purple, Red, Silver, and Turquoise. 

Project 321 Hub Teardown AndrewM

Rear axle removal is a quick job involving two wrenches and a 1.5mm hex key. Great news for anyone sharing a hub between 142/135 spacing bikes or, in the near future, 148/141 spacing bikes. 

Project 321 Hub Teardown AndrewM

These hubs spin ridiculously easily out of the box without any break in. This is a combination of the very light lube on the driver and in the bearings and the fine bearing tension adjustment. 


P321 hubs can be crank-it-to 11 loud or almost silent by swapping between two different sets of magnetic pawls. The loud option comes with a slight increase in drag, but the louder pawl option produces 51% less drag than the previous generation with spring backed pawls. The quiet pawls make for a 68% reduction. 

Project 321 recommends only Dumonde Tech Pro X Freehub Oil for lubrication of the pawls and drive ring. 

The magnetic pawls with both the loud and quiet options and the high-quality EZO bearings really sealed the deal for us. - Dustin Adams, We Are One
Project 321 Hub Teardown AndrewM

Once the freehub driver is removed it's an effortless job to remove and install pawls from their seats. The loud option is LOUD. The quiet option is like a series of odorless cat farts - you have to want to notice them. 

There are actually four freehub driver options. That's XD (SRAM) and HG (Shimano) available in two different pawl setups. Drivers are then available in two different engagement options: 6x2 (6 pawls with 2 pawls engaged at a time) and 6x3 (6 pawls with 3 pawls engaged at a time). 

The 6×2 driver yields 1.7° engagement and the 6×3 option yields 2.5°. In theory, the 144 points of engagement from the 6x3 option is robust enough for single speeding Clydesdales.

Project 321 Hub Teardown AndrewM

For reference that's the quiet option on the left and the noisy bastard on the right. 

Watcha Spinnin' On?

"A West Coast capable hub" - Dustin Adams, We Are One

Project 321 offers hubs with Enduro ceramic hybrid bearings (+$100 USD) or high precision EZO Japanese made steel bearings. I find it hard to imagine the hubs spinning any nicer than they do with the EZO setup and my limited experiences with ceramic hybrid bearings have been poor. But, to each their own, options abound and etc. 

Usually between Jeff and myself a teardown involves loading up any bearings with heavy water proof grease but he's spent all summer rebuilding Remi and Jesse's hub bearings with light oil and no seals so we split the difference and left the hubs as stock. 

Project 321 Hub Teardown AndrewM

The machined pockets behind the drive ring serve to hold significantly more oil than similar designs. This should cut down on maintenance and help dampen noise. 

Project 321 Hub Teardown AndrewM

Rather than stuffing the bearings full of waterproof bearing grease - the usual Wet-Coast MO - the stock, very light, lube was left in place. They just spin so nicely out of the box it didn't seem right to gunk them up. I'll see how long that lasts. 

It's a very quick job to pull the axle and pop the seals on the most outboard bearings, the ones that most often have performance issues from water ingress, so I'll keep an eye on them with hopes that the tight tolerances, extra oil in the drive system, and the freehub seal keep the water out. 

My experience with what initially seemed to be under-sealed True Precision hubs has taught that machining tolerances can vastly improve bearing life in wet conditions.

Project 321 Hub Teardown AndrewM

A double row of bearings on the hub driver meet straight up against the driveside hubshell bearing. Add the outboard freehub bearing and the non-driveside hubshell bearing and that's a total of five. 

Project 321 Hub Teardown AndrewM

The double seal on the freehub driver keeps oil in and crap out. 

Up Front

To some extent a front hub is a front hub. The P321 hub has easy to swap but tight-to-remove end caps sealed by o-rings, and the anodizing perfectly matches the rear. 

Project 321 Hub Teardown AndrewM

Not just an excuse for Jeff to bust out his Knipex pliers, these end caps are actually a bear to remove. 

Project 321 Hub Teardown AndrewM

Speaking of bears. This wheelset was built by my friend Dumpster Bear. The spokes are Sapim Lasers, the rims are Race Face ARC (40 front | 30 rear) and the nipples are TLC anodized brass. 

How To

Anyone who has successfully replaced bearings in a hub is fully equipped to tackle a complete teardown on the new Project 321 hubs. All the same the company is currently working on building a repository of How To videos to help guide riders through the ins and outs. 

Project 321 Hub Teardown AndrewM

No special tools are required to open the P321 rear hub; a couple of thin wrenches and a hex key are the keys. Bearing removal & install is as per almost every other non-King hub. 

Hubs can be ordered through any P321 dealer or directly from the website. The hubs carry a ten-year manufacturer's warranty on the shell and axle and a three-year warranty on the pawls, drive ring and freehub body. 

Pricing ranges depending on options and is available here


+1 Andrew Major
James Vasilyev  - Oct. 2, 2017, 8 a.m.

looking forward to the long term review and if the quiet hub remains quiet for the long haul. can a 142 rear hub be converted to 148 to go to a new bike?


+1 bikerider
Andrew Major  - Oct. 2, 2017, 9:10 a.m.

There are no hubs that I know of designed to convert between Boost and non-Boost.

You could use Problem Solvers' Boost kit to make that swap(142->148) but as with the Wolf Tooth kits it isn't a factory solution. 

I'd love to see more companies (Chris King, Hope, DT) offering factory front and rear Boost adapter kits for the troves legacy hubs out there. In the case of P321 I imagine the demand for conversions kits would be extremely small since they're a new product.

By design I can't see them getting louder over time other than maybe lube breaking down - and telling me it's time for a clean & lube? I'll report back once I've thrashed them solidly.


+1 Andrew Major
Shoreboy  - Oct. 2, 2017, 11:26 a.m.

Id love to see legacy adapters too, but its very unlikely to happen.  There is no incentive for these companies to offer Boost adapter kits.  A new set of hubs is going to earn them alot more $$$ than $50 worth of adapters. Why manufacture something that is going to take away from people buying new and more expensive items from your company?  I dont agree with it at all, but it is the sad reality of how the industry seems to function now.


Andrew Major  - Oct. 2, 2017, 8:14 p.m.

I know I pick on Chris King a lot on this subject - it's out of love I promise - but on the one hand making an axle & brake spacer kit for legacy hubs is about practicing what they preach from an environmental perspective and company philosophy --- I.E. product you can buy and service forever. 

On the other hand, a King axle and brake adapter kit wouldn't be $50. It would probably be closer to $150... per wheel. There's money to be made in supporting legacy product along with the feel good fist-bump of a rider being able to lace their 15-year old King hubs into a fresh set of 30mm wide 29'er hoops and keep ripping along on trend. 

It goes without saying I'd love to see Hope, Industry-9, Project 321, True Precision, Onyx and etc who make their own products in house all doing the same.

The nice thing about making products in house is if there is a demand it's really easy to support it by making longer axles and rotor spacers. 

With this being a brand new hub I'm sure the business case (~zero demand?) isn't there for P321 to offer such a kit as this time - they make Boost and non-Boost hubs with specific shells/axles. That said, they are offering extensive warranties on the product and I'd guess assuming their hubs will end up surviving at least a couple frames so if enough riders are looking to roll forward their 135/142 hubs to Boost frames maybe they'll consider making their own axle kit?


bikerider  - Oct. 4, 2017, 11:51 a.m.

Hope has a rear boost kit listed:


Rear hub conversion kits: 

Pro 2 EVO/Pro 4 Rear Boost Conversion Kit HUB493

It isn't available yet though.


Andrew Major  - Oct. 5, 2017, 2:59 p.m.

That's a great find - originally they weren't going to make one.

Of course for Hope, DT and MOST I-9 hubs Wolf Tooth makes awesome kits for Boost conversion.


awd505  - Oct. 14, 2017, 1:21 p.m.

Nice to see Project 321 get press for their high quality, smartly designed hubs.

They have been using Dumonde Tech Freehub Grease for many years for a reason.


Michael  - Nov. 6, 2017, 12:17 p.m.

Running one of these now in the quiet version. Definitely a " where have you been all my life" moment love this hub. I hope it's up to the task long term.


Andrew Major  - Nov. 6, 2017, 1:11 p.m.

So far this one has been a treat - but long term will tell.

I do like that unlike other instant/silent hubs the design is very user serviceable with no special tools needed. 

If you want to have it a long time it’s pretty easy to stay on top of maintenance. Dumond Tech freehub grease can be easily ordered in by any shop.


Please log in to leave a comment.

Trending on NSMB