Trouble after installing new front wheel bearings

[markmartin]

Hi all,

I mounted my new '87 yzf front wheel yesterday, and ran into a problem.  When I tightened the axle, it caused the wheel to stop from turning freely--as though the brakes are 3/4 on.  When I loosened the axle, the wheel would turn a little easier, but still not as freely as I think it should.  I took the wheel off and noticed that the bearings were very hard to turn with my finger.

A little history on the wheel-- I bought this wheel on ebay. All looks good and existing bearings worked OK.  I removed the existing bearings, sent the wheel out to sand blast and powder coat, and then installed new bearings and seals.  Powder coater plugged the bearing housings -FWIW.

It appears to me that the spacer is too long, or I drove the bearing down too far into the hub and now the spacer is binding the wheel bearings, not allowing them to turn freely.  I removed one bearing tonight and it works fine, and now that the other bearing is not being 'pushed' by the  spacer' it works fine too.  I measured from the top of the hub (see picture below) to the bottom, and from the top of the hub to the top of the spacer, and the top of the spacer is sticking up about .015 inch up higher than the bottom of the seat where the bearing would sit.  This make me feel like I seated the bearing too far down and it's pushing on the spacer and binding the bearing.  ??

I'm assuming that the spacer should just barely touch each bearing and turn with the bearings.  I'm not sure this is correct.  If I seat (or attempt to seat) the bearings to the bottom of the housing they appear to bind.  

Is the right method to just seat the (2nd) bearing until it just touches the spacer?  ...and not try to get it to the bottom of the hub?


Hope this all makes some sense.  Let me know if I need to clarify anything / everything.

[FJmonkey]

The bearings should be a press fit into the wheel. The inner race of the bearings should rest against the spacer inside the wheel. When properly sized it lets you torque down solid against the two inner races against the spacer in between and still allow the wheel to spin freely. One or more parts are out of spec and it is causing your binding. The picture looks like your spacer might be damaged. Hard to tell.

[craigo]

I had the same problem when my front wheel came back from powder coating. I have to ask, did you remove your forks or move them in any way? I took off my forks and polished them. When I put my wheel on, the spacer opposite the speedo drive seemed too long. I thought the bearings were installed incorrectly, so I took the wheel back to the shop that installed them. With me present, he measured and they were fine.

So I loosened the forks and rotated them until the spacer fit. Tightened everything down and all is fine.
I was wondering if my forks were bent as well, but that was not the case. My bike runs true and straight with not an ounce of wobble, no odd dragging of the brakes or any other issues.

CraigO

[axiom-r]

I think FJMonkey has it right- the inner spacer is supposed to contact the bearing on either side and when the axle tightens up it holds the whole center spacer assembly tight. Then the outer bearing (and the wheel) spin around the motionless center spacers..... 

If that is correct I would think that your spacer is not long enough perhaps and tightening the axle allows the outer bearing to bind...

Are you using the yzf spacer that came with the wheel?

tim

[markmartin]

Are you using the yzf spacer that came with the wheel?

tim

My mistake on the wheel model--I'm using an '87 FZR wheel.   But to answer your question, yes it is the same spacer that came with the FZR wheel.

[FJ Flyer]

Are you sure the bearings are seated all the way against the rim when installed?

[markmartin]

. The picture looks like your spacer might be damaged. Hard to tell.

Yes, I dinged up the spacer punching the bearings out with a steel 'drift' instead of brass.  However the length or the spacer didn't change and I removed any burrs.  That said, the spacer, bearings, and seals from the FZR are all the same part numbers as the (my) OEM -- FJ wheel, so I'll see if I can get the spacer in the FJ wheel out tonight without damaging it and drop that one in the FZR wheel.

Thanks for the affirmation that the spacer is supposed to make contact and turn with the wheel. Craig, thanks also.  I was careful to check the alignment of the forks checking for stiction and not tightening up the fork braces prematurely, and even before the fork braces are tightened, I'm having a problem with the bearings apparently binding.  Tightening the axle make it worse.

I'm still wondering why the spacer would be .015" proud of the bottom of the hub? It seems that when I finally seat the bearing down in the hub the spacer pushes up too much on the center of the race causing it to bind.  I could make a .015 shim to install under the bearing, but then I'd  be adding parts to the assembly. 

[markmartin]

Are you sure the bearings are seated all the way against the rim when installed?

Yes, pretty darn sure.  It looks like to me that the problem is when I seat them all the way down, the spacer appears to be too long and pushes up against the inner race too much.  I'm glad to hear though that they are in fact supposed to be seated all the way down.  That's what I assumed I was supposed to do and was trying to do.

I can't imagine that the sandblasting removed any material from the bottom of the hub(s).  ??

[fj1289]

Definately sounds like the bearings were sideloaded for some reason. 

Compare the FZR and FJ inner spacers.  I'd use the one that looks to be in the best shape.  Should be the same length -- I used the FJ one when I did the swap years ago because I didn't get a spacer with my rim. 

I'd suggest installing the left bearing first - ensure it seats in the bottom of the bore.  Drop in the spacer and make sure it can make even contact with the inner bearing race.  Install the right bearing until the inner race is flush against the spacer -- don't force the outer race of this bearing to the bottom of the bore.  Ensure both bearings turn freely. 

Oh, and after the bearings have been in a bind like that, you really need to get new ones...

(a good use for the old bearings is as a bearing driver - just grind a hair off the outside diameter so they slip in the wheel hub without interference.  Works better for me than a large socket) 

[Mark Olson]

I had the same problem as well and just wacked the inner race back the other way until the binding went away.

so yes the spacer contacts the inner race and holds the wheel in place.  My bearings are not all the way into the wheel by just a smidge like yours will be.

your option is to cut down the spacer or leave the bearing not quite buried into the wheel by a smidge.

I have been riding with my wheel like this for years with no problems at speed or in corners.

[1tinindian]

I had the same concern last January.
http://www.fjowners.com/index.php?topic=5781.msg50501#msg50501

It seems to me that it works fine once installed on the bike.
I'm sure a few miles will settle everything into place, I have no worries.

Leon

[markmartin]

Thanks for all the answers guys.  I'm going to install the bearing until it touches the spacer.  No further.  Leon, thanks for the link to the previous thread.  I'm guilty of not using the search function. And thanks to y'all for letting me lean on the collective knowledge.  Put me down for an IOU for beers all around! 

[Yamifj1200]

"I'm going to install the bearing until it touches the spacer.  No further"





I hate to disagree with your logic but, there is a reason for the seat in the wheel hub. The wheel seat locates the wheel bearing in the wheel hub making the hub, wheel bearings and spacer a solid unit it also supports the wheel from lateral loads. Its your life and you can decide to do as you please, but I highly recommend cutting the space to the proper length and install the bearing to the seats. JMO


Eric M

[racerman_27410]

i agree with Eric.... the shoulder is there to keep the bearing from tweaking sideways in the bore.... I promise you if that happens while you're riding it wont be a good thing...... especially on the front wheel... wouldnt be any saving that one.



KOokaloo!

[markmartin]

What if I shim the bottom of the hub until the shim is even with the top (face)  of the spacer.  That way the bearing should be seated and touching the spacer.  This way the combined length of the speedo-bearing-spacer-bearing-collar should remain as it was designed.

Whatdaya think?