Started the overhaul of my Fatbob in '06 when my friend ordered front end, Dash, etc etc and a set of tires and wheels. He mounted the front wheel when he mocked up the front end.

He lost interest in the project and I reclaimed the bike last July. When I got to the point to put the new rear wheel on, I found the bearings inside just fell over when I touched them, to I assumed they weren't the right ones.

I talked to my on-line parts supplier (my "dealer") and he sent me bearings with races, along with the hub spacer. I started putting things together and found out the spacer was too short. I must have ordered 3 times and couldn't get one long enough.

I understand that the spacer should just touch each bearing, to keep them from being pushed in (along with the shoulders on the races). I decided to make my own out of 3/4" iron pipe. I cleaned the hub, measured outside to outside for overall width, and looking inside I could see the shoulders. I measured one and found that it was 1" deep. Now, I'm recovering from shoulder surgery, to I limit my manhandling of things as much as possible, so I figured if one side was 1" (sprocket side, BTW) then the other should be as well. I took my overall width, subtracted 2", and figured that should be my length. Since I new there would be a lot of fine tuning, I made a mock spacer from a wood dowel. I put a race in one side for the dowel to but up against and made a gauge that would rest on the shoulder on the other side, but everything was way off. I kept chopping down the wood until I had the perfect fit and then cut the final from the pipe.

That's when things got ugly! The sprocket side bearing installed perfectly. When I tried to install the disc side, the bearing wouldn't go in all the way. I kept monkeying with the spacer and then finally just decided to take it out. Lo and behold - the bearing still wouldn't fit!

I pulled everything out and cleaned it all up again and this time measured BOTH sides. On the sprocket side, from outside lip to the shoulder that holds the race in is about an inch. All fits good. On the disc side, from the lip to the shoulder is about .5" - enough room for the bearing but not with the grease cap. Of course, this means the bearing will fall out as soon as it's not on an axle, and I know that just ain't right.

Wheels have never been my forte (which is why I'm asking for help). I see one of 3 things, and I don't know which one is right.

1. The wheel is defective or for something other than what I'm trying to use it for

2. There is a different type bearing I need for the short side.

3. I'm just putting it together wrong (not out of the question)

Any advice someone can pass along, it would be much appreciated. I can provide specific measurements, details of pics if it would be helpful.

Thanks!

Drifter

 

I have been working on a hub project and I noticed that the recess that the bearing fits into is deeper on one side than the other. The side that is less deep is the side that the bearing should bottom out completely. The deeper side bearing doesn't go in all the way because it presses up against the spacer.
What year is your Fatbob? What is the wheel off of?
What did you mean by
"from the lip to the shoulder is about .5" - enough room for the bearing but not with the grease cap. Of course, this means the bearing will fall out as soon as it's not on an axle"?
Does the bearing not fit tight? You should have to tap the bearing into place, how could it fall out?
What is the grease cap?
Is this not a normal sealed bearing?
How wide is the bearing?

 

Are you sure the wheel was not designed for ball bearings? You still need a spacer but the dust seal is not needed so no space needed. Just a thought.

 

I appreciate the replies. Hopefully I'll find a resolution so I can A) get the brakes and pipes mounted and B) get this dang thing off the lift so it's easier to work around!

The bike is a '79 FXEF. Pretty much stock with the exception of some obvious road repairs my brother/the previous owner made - nothing concerning the rear wheel tho.

I have a friend that 10 years ago offered to help me do a quasi-restore. He was a parts dealer because he did a lot of bike work on the side. We ordered a seat, front end, a bunch of misc chrome, the billet Bayonet wheels and tires. He mocked up the front end with the new wheel, and then things slipped off track. We never returned to the project.

6 months ago I brought the bike back home and took it down to the frame and engine/tranny and started cleaning/painting/replacing parts, etc. When I brought the bike home the original rear wheel was installed and the new one was in the parts pile.

Because of all this, I don't know the specs on the wheel. I also have run into a problem getting a front caliper because I can't determine the year of the wide-glide front end - but that's a different challenge. I contacted the 2 possible suppliers for the wheels and front end, but they said it's been so long they no longer have records, and all I have is credit card receipts.

About the wheel:

I don't have measurements down to a gnats butt (I don't think we need that much detail) but I have enough to get the gist. My measurements are in inches.

Currently I have the sprocket and disc mounted. From one side of the hub to the other (measured with a tape measure through the hole) it looks like exactly 7". Measuring the diameter looks like 1.77".

On the sprocket side, measuring with a caliper I am reading .97" from the shoulder to the outer edge of the hub.

On the disc side, measuring with a caliper I am reading .56" from the shoulder the the outer edge of the hub.

I've never done wheel bearings before. The new wheel had bearings inside, so I just did a wheel swap (3/4" axle, btw). Something wasn't right so I pulled the wheel and started poking around and when I stuck my finger inside the bearings fell over, so I assumed they probably weren't the right thing.

I called J&P (my go-to parts guys) and talked to one of their wrenches. I explained what I saw (not aware of the spacing differences) and he send me a hub kit that included Timkin tapered bearings, races and a wheel spacer.

When the parts came in, I saw the bearings looked right (and wouldn't fall over!) but the spacer was too short. I ordered another spacer but had the same problem. I finally decided in the interim to make my own. I know the spacer should just graze the bearings, so with one installed (race, bearing and grease cap - on the sprocket side, it turns out) I used a wooden dowel, slowly trimming it down to get exact length, and then used that to cut a spacer out of 3/4 pipe.

When it came time to put everything together, I pulled it all apart, cleaned everything, and put in the sprocket bearing. Tapped in the race, put in the bearing, installed the grease cap and everything fit flush.

Flipping it over, I installed the spacer, tapped in the race, put in the bearing, and I think at that point the bearing was protruding a little. Putting on the grease cap wasn't even an option. Standing the wheel up, the bearing fell right out.

I've heard a little about ABS bearings, but haven't researched then yet so I don't know if they are wider (deeper?) or skinnier, so I don't know if I'm dealing with an ABS wheel (is there such a thing?). Or do they make skinny sealed bearings? Or do I have a f*cked wheel?

Any thoughts you have on this is appreciated - if I didn't have so many other things to work on at the moment on this bike this would be driving me nuts!!!

Ride safe if you can get out there!

Thanks!

Drifter

 

I think you might be trying to install old school tapered bearings in a wheel meant for modern sealed bearings.
What is the outside diameter of the race that fits well into the bearing recess?

 

45.2mm/1.78"

They both fit well, it's the depth that's off

 

I think that you have a rear wheel that needs modern sealed bearings. You already know the inside and outside diameters, now you just have to figure out the width. That will be around .500". I'm sure someone knows what bearing you need. When ordering them, I wouldn't go by the year and model of the bike, just go by the dimensions of the wheel.
The race does bottom out on the shallow side but that isn't in far enough, right?

 

Correct.

After remeasuring, it looks like it's metric. The shallow side is 15mm, the deep side is 25mm.

From what I've read it sounds like I probably need to get 2 15mm sealed. Set one in the shallow side, put in right size spacer and let the spacer determine the positioning of the bearing on the deep side. Either that or get one of each - I think the end result would be the same.

Guess I'd better start looking for a source to get them - that seems to be the hard part.