Wheel bearings.

I just installed my bearings in my bike and the front bearing move together. The back wheel bearings spin together as well. Meaning when I spin one bearing the other spins. Is that okay? Will that cause any issues?

Thanks!

You drove the bearings in a little too far such that the tube between them is being pinched between the two inner races. Most likely it won't cause a problem unless the bearings are binding.

Not sure why the wheels are made how they are but I've always been of the thought to drive the bearings in until they bottom in the bore, but if you do that with the stock KZ wheels there will be problems like you noticed. Another problem is that can come up is if one bearing is in too far you can't get the snap ring installed without binding the bearings. Don't ask me how I know.

I probably won’t worry about it. Cuz I kinda feel like now that they’re in there, best bit mess with them.

Thanks!

What wheel bearing kits did you get? Is the correct collar/spacer in there?
I don't see how they can be driven in too far: they should go in all the way until seated.
I'm assuming you drove them in correctly with bearing driver seated on the outer races (not the inner races).
Since they're in, just make sure the bearings aren't binding & the inner races aren't being deflected.
I would probably rig up a homemade wheel stand, then install the axle & spin the wheel to check it.

martin_csr wrote: I don't see how they can be driven in too far: they should go in all the way until seated.
I'm assuming you drove them in correctly with bearing driver seated on the outer races (not the inner races).
Since they're in, just make sure the bearings aren't binding & the inner races aren't being deflected.

When installing bearings into my 750 wheels I drove in the first bearing until it bottomed. Then I dropped in the spacer tube and proceed to press in the second bearing. I was tapping tapping but the second bearing wouldn't go in far enough to allow installation of the snap ring because the spacer between the bearings was being compressed. I had to pound the first bearing backwards, striking it on the inner race :S , which I wasn't comfortable doing, in order to gain room for the second bearing. In the end I wound up pounding out the first bearing and started fresh with another new bearing, only this time I didn't drive it in all the way until it bottomed.

Not sure what you mean by binding. They’re installed. They do spin when you put weight on the front axle. It’s just by hand they’re a bit harder to turn. I’m sure after I get one the road they’ll be fine.

Thanks!

They should spin freely.
Steve

Do you think it will harm them if they don’t spin “freely”? They spin like I said, they just require a little more effort than I would have thought.

Thanks!

You should do what you can to make them relax.
Steve

Coming in late to this thread, so it's too late probably to try this. I have always frozen the bearings ahead of time (like the night ahead), and heated the hub. I've used a plumber's torch (acetylene bottle), small propane torch, or even a good heat gun. I play the heat around and around the clean bore to get the hub evenly warm. I check that it is ready by putting a bit of spit on a finger and touching the edge. If it sizzles, it's ready (seriously!!). Grab the bearing from the freezer, and using the axle with a proper spacer to push on the outside race, I find the bearing will almost drop in, with little to no effort. The hub will cool pretty rapidly and the bearing should stay right in place.

Once it is cooled on one side, I put the spacer(s) in place from the opposite side and repeat the process. This puts very little strain on the bearings.

I was taught this method at Butler and Smith, the BMW headquarters in NJ, when I worked as a BMW bike mechanic. It works.

If it was my front wheel & the bearing didn't seem right, I would look into having the spacer cut down a mm or two or however much is necessary. or install a round shim or washer between the wheel & bearing. Or you can just do what Nessism did. .nothing is easy on an old motorcycle.

To install bearings I put a small amount of grease on the wheel & on the outer races. This seemed like the common sense way to do it as the grease lubricates the surfaces & deters corrosion afterwards. They went in easy doing it this way. Later I checked the manual out of curiosity & that's what the Kaw manual says to do. I don't like the idea of heating & freezing as this introduces condensation which then leads to corrosion. probably inconsequential, but nonetheless....

....

I too am late to this but I saved this pic years ago when I was explaining side loading to a friend. Sounds like the OP got his answer but this pic explains it well. Basically the second bearing should be tapped in until it just touches the center spacer. This prevents the bearing from side loading when the whole axle is tightened up as the center races, inner spacer, and outer spacers get "pinched together". The wheel hub just rides on the outer races and does not matter if it isn't seated all the way in the hub. Every bike I've had and currently have are this way.