what is the purpose of a bearing spacer?

i went o install new bearing on a front wheel and got them in fine, i went to put the circlip in and the bearing wasn't in far enough so i taped in it a bit more, circlip went in but now the spacer is binding on the bearing, what the hell is that thing for if there are steps in the hub to prevent the bearing from going too far in anyway

the inner spacer is there to denote the torque or pressure applied when axle is tightened.

If it was not there, the bearings would collapse when axle was tightened down.

would assume you are talking about part #12

www.cmsnl.com/kawasaki-1978-kz1000-a2a-k...t/66391.html#results

4TheKZ1000 wrote: the inner spacer is there to denote the torque or pressure applied when axle is tightened.

If it was not there, the bearings would collapse when axle was tightened down....

+1
This is because the steps in the hub determine how far the outer bearing races will seat, but don't determine how far in the inner bearing races can be seated. When you tighten the axle nuts (collars) they squeeze against the outer surfaces of the inner bearing races. If there was no spacer between the two inner races they would be pushed toward the center of the hub when you tightened the collars resulting in lateral pressure against the balls and ruining the bearings. The central spacer ensures the inner races of each bearing are kept from being pushed out of alignment of the center-line of their respective bearings. Ed

the purpose of a bearing spacer is to ensure that once the bearing is in space it stays in orbit

4TheKZ1000 wrote:

Attachment thCA7ULCMK.jpg not found

this is a excellent example of a vintage NC1701
this is the modern replacment 6208.C3
it is shown without a BEARING SPACER


www.bearings-direct.com/vmchk/Deep-Groov...ing/flypage.tpl.html

4TheKZ1000 wrote:

Attachment thCA7ULCMK.jpg not found

lol.

so it doesn't matter that the inner races are binding on the spacer?

`as long as the c3 rating keeps it in orbit
its good to go

DoctoRot wrote: i went o install new bearing on a front wheel and got them in fine, i went to put the circlip in and the bearing wasn't in far enough so i taped in it a bit more, circlip went in but now the spacer is binding on the bearing, what the hell is that thing for if there are steps in the hub to prevent the bearing from going too far in anyway

Morning Sir
I had same problem on my 1975 Z1-B 900.
( If you are talking about front wheel bearing / spacer) I ended up having to remove about 20-30,. Thousandths from my front wheel spacer. After that all fit properly. I surmise that perhaps there is a just so very slight difference in Bearing width's, at least thats what I saw measuring with digital caliper, there was 20 -25 thousandths width difference in my aftermarket bearing and original. Thats just my experience, I am sure others have something to share.
Just my Humble opinion.
TennesseeZ Ed

I'm a bearing engineer - for real, so I will give you the low down.

When you clamp through the axle the load travel through the inner races.the spacer between the bearings ensure that the clamp load goes directly the the inner racesand never through the balls and into the outer races.

Without the spacer between the inner races. you can actually Brinell (dent) the outer or inner races during clamping up the bearing, and/or create an excessive axial pre-load through the bearings which will significantly lower the bearings life.

Without the spacer you will take up the C3 or whatever manufactured internal clearance is built into the bearings.

In summary - don't run the bearings without the spacers! If necessary, trim the length of the spacer to ensure that it fits during assembly and NEVER install bearings into a housing or on a shaft by pushing on the race that is free. i.e. when install the bearings into a hub (outer race interface), press them in via the outer race, and conversely if you ever have a bearing that is press fit on a shaft - this should be pressed on through the inner race ONLY - used an appropriately sized tube as a mandrel, if necessary. Doing this wil ensure you do not Brinell/damage the bearing during assembly. Also bashing bearings in with a hammer doesn't help either. :silly:

What wheel bearings did you install?

i installed the All Balls kit. i always tap the outer race when installing these, as per the FSM. it does seem like the collar is a bit too long though.