Quick-Release Bearing Holder

Hey, I made this quick-release bearing holder (see picture). The parts are all off-the-shelf, and cost about $15 per holder. The machining was so simple even I could do it. I made 4 in about 1.5 hrs, but most of that was head scratching time. My friend Walt (www.waltworks.com) is going to weld up a frame with these, so I’ll let you know how it works out.


Looks very good, I would love having a quick release bearing holder. I hate having to unscrew them to remove the tube or tire. I somehow doubt that they are as strong as a bearing holder that uses screws, but they still look nice.

I bet they’ll be plenty strong enough. I will turn Owen and Nate loose with one and we’ll find out.

Very cool!
What’s holding the other side of the bearing clamp together? Is it a hinge? Do you have a reverse angle shot that would show how that part of the bearing holder is held together?

Very awesome. It could be very useful if you are in the middle of nowhere and get a flat/slashed tire and need to change the tube, or have to walk 10 miles…

I would buy a frame with it.

Hi John;

Yes, it is a hinged clamp. I’ll post a reverse-angle shot after I get back from my ride. I’ll also put together a parts list.

Finally!! someone finally made quick-release bearing holders!
Andrew and myself were discussing this awhile back and it just seemed like such a good idea!


ps: there’s another unicyclist called Owen??? that makes me not so special anymore…i am saddened by this:p

Nice work on the bearing holder a simple and staight foward design. Looks plenty strong enough considering all the other things that are held together with quick releases.
Are there any problems with it squeezing the bearing race to tightly?
Cheers Dave

I’m not sure about squeezing the bearing race because I haven’t built the frame yet, but I doubt it will be a problem, the lever has a barrel nut in it, so the 10-32 bolt can be adjusted so that the fit is just right.

The parts list;

  1. Hinged Shaft Collar; part no. 57145K83, McMaster-Carr,
    www/mcmaster.com, $12.54

  2. Rocky Mountain QR Seat Collar; Cambria Bikes, www.cambriabike.com $5.95

  3. 10-32 Stainless Steel Socket-head bolt. 1-3/4”, scrounged this, but probably $0.39

  4. 3/8” OD Aluminum rod, drilled out to 10-32 clearance, scrounged.

So, I was wrong, they cost about $19 ea.

I chose that particular seat collar because it has a barrel nut. This allows complete adjustability.

Here is the reverse view, the hinge on the collar is really neat because it allows the collar to open all the way up, making the machining a lot easier.


That’s a very good idea and from the looks of it, I think it should work well. What type of uni are you going to use it on? Are you able to adjust the tension without tools? Can’t wait to hear how well they work.

Ah, you’ve hit on my next project. I am building a Beast 29er. It will have a Profile Hub with 190mm cranks (danscomp.com) and a new KH29XC rim with a ExiWolf 2.3 tire. We will then build a 4130 frame and include the bearing holders. I will let everyone know how it works out, and you’ll be able to see the real thing at Moab.

The holder can be taken apart and the tension adjusted without tools because the bolt screws into the barrel nut (in the center of the cam). so, it is truly a quick release in that sense.

I absolutely love it! As Owen said, we have been waiting for this to be made for some time now. This is very exciting. I haven’t yet had my new muni frame made…are you selling these things?

190mm cranks?? Have you ridden with that length before? Do you have ridiculously long legs?

Thanks for showing us all those beautiful bearing holders. I’m amazed that all the parts were available for purchase and didn’t have to be made specifically.



nice work on the bearing holders!

also, to echo andrew carter WTF! 190mm cranks? i’m 6’4 and run 180mm on my mountain bike and 175mm on my touring bike. 190 ona 29er is crazy. i’d vote 150s or shorter. maybe 160s more muni.

Nice work. I have given thought to quick releases myself but just haven’t had the time to devote to it. I am the guy that put the disk brake on a KH 24. Since I put new bearing holders on I thought about it but in the end time ran out. It still may be a future project but since I just had it painted it will have to wait.

I do have one suggestion. You may want to have something secure the lever from releasing. Since it releasing down and it could unclamp or even catch on something and release. Just a thought.


Thanks to everyone for all the nice feedback.

Right now I don’t have any plans to sell them. I’m trying to convince my friend Walt (waltworks.com) to make unicycle frames for sale, but he seems to be stuck on those two-wheel contraptions. Also, I want to test these out to see how they work. Then I’ll know if there is a problem with the level hitting something and popping open. I suspect not, take a look at the bottom bearing holder onyour Muni frame and see if there are any scratches, I’ve never hit mine on anything. I’ll keep everyone posted on how it works and availability. Maybe I’ll open up a sweat shop with Owen and Nate (they’re 14) - just kidding.

Yes I do have rediculously long legs, but not as long as George Barnes’ who is the tallest unicyclist I’ve met so far. My main Muni has been a 26" with 175s and it has worked really well for me, except that the hub is almost broken (Nate bent it doing a 6’ drop). I have a 29er that I built with a UDC hub and it also has 175s (150s when I was commuting on it). I have been riding the 29er with 175s on trails and I like it because it goes faster (I’m a low rev guy, was when I rode bikes too). I don’t feel I have as much control or torque as I would like, or had with the 26/175. 29/190 is nearly the same ratio as 26/175 if you measure the actual tire diameters, so when the KH29XC rim came out I decide to take my Christmas money and go for it. I’ll let everyone know how it turns out, and if you are at Moab this year you can ride it.

If the hinge is forward facing there shouldn’t be a problem, most things that might catch the lever would slide off. The idea looks great, I just need to find a UK supplier of hinged shaft collars…

Jim_Rob - Boulder must be a fantastic place to ride, it is one of the places I would love to takes some Uni’s to, I had a business trip there a few years ago.


Hi Keg;

I’ll bet McMaster-Carr would ship to the old country. Yes, Boulder is a great place to ride, but all the trails just to the west of town along the Flatirons are closed to “wheel conveyances”, yes that means strollers too, so you have to travel a bit to get into the bike trails. But sure to drop us a line if you make it back out here.

That looks excellent. I haven’t read all the posts in the thread, but I did see that those are stock parts. That just looks like a 2 bolt clamp with a hinge on one side and a quick release on the other. I love how you kept it to stock, easy to acquire parts. I wanted to do something like that on my trials frame, but nix’d it when I noticed how hard it’d be to make a good version.

That will be creat for commuter wheels and strictly muni wheels, but no good for trials or urban 24’s. A bad pedalgrab will shatter the quick release. Maybe if it could be oriented in another direction…

It sounds like a great idea for switching between Muni and commuter unis. however gerbel brings up a good point. How durable is the dwick rease? Is there a way to make the design more streamline, so if ou did to some grabbing or abuted the QR it wouldnt break…

A metal casing could be placed around the quick release so it would be protected from grinds/slides/abuse but still easily accessable.
My Sloppy Idea(MS paint is fun):

Good idea Catboy. I think the best solution would be to machine a slot in the bottom part of the collar and fabricate a level that would fit into it. That way the body of the collar would protect the level and mechanism.