profile hub and making a uni

Ive ordered a profile hub, hope its worth it.

Instead of buying a uni that fits a 3 inch tyre for a couple of hundred dollars, ive devided to have a go at making one, The only problem i can think of is how to make the bearing holders, Can you buy bearing clamps? or would you have to machine them?

Im making the uni out of good quality cromolly or steel tubing, and doing the welding at my university. Any advice on things to watch out for?

Cheers, JAmes

Jimmy,

> Can you buy bearing clamps? or would
> you have to machine them?

You can get stanped steel bearing holders from unicycle.com. They’re
lighter than any of the machined steel bearing holders I’ve seen.

>
> Im making the uni out of good quality
> cromolly or steel tubing, and doing the welding at my university. Any
> advice on things to watch out for?

Yes, don’t overbuild it. Also make sure you get the pieces straight
when you weld them all together. And go for lots of tire clearance yet
narrow overall width.

Chris

I made my own uni last week. I used a lot of Chris Reeder’s measurements for tube diameters, and it looks quite similar too. The only real differences between mine and the ones Chris built are that I didnt angle the tops of the legs, I didnt dent the frame in and I made it all out of stainless steel.

Like Chris said, dont overengineer it. I was majorly concerned about how strong it would be, but found that once bolted together with the wheel, there is NO noticeable flex anywhere in the whole setup. I would even concider going to a thinner wall tube if I made another one, but considering the weight of a Nokian Gazzaloddi, I wont bother.

I chose not to dent the frame in for ease of jigging and re-manufacture, and Im glad I did. So far, Ive hit the frame only once with my leg, but Ive hit the tyre enough times to bruise the insides of both my knees. Personally, I have no problem with the width of my frame, just the tyre!

All I did for bearing caps was order them from unicycle.com. Heres the link:

http://www.unicycle.com/shopping/shopexd.asp?id=206

you will need 2 sets per unicycle.

When I made mine, I made a jig out of a sheet of plywood and aluminium angle. I used stainless tubing, but you can use 4130 chromoly tubing. You really are SUPPOSED to “normalise” 4130 after welding, cause it becomes brittle, but it shouldnt be too much of a drama on a uni. I’ll have photos of my jig and the completed uni up on my website when I fix my scanner.

Good luck,

Leo

bearing distance??

Right, ive got my cromolly, Im modelling my design on a chris holm mountain frame, only problem is, i dont have my profile hub yet, so i dont know how far apart to put the legs?

Does the profile hub need lots of spacing to fit a three inch tyre?

Ive decided on brazing the joints together instead of tig welding, as i know how to braze, and its cheaper. should be plenty stong enough!