Hi All,

I was not able to find this info from the old posts

Any one know the length for the rear wheel spacer (#7) in the image below (Honda CB900F)?
rwheel.png


When I bought the bike, I took it to a shop to change the tires. The shop also replaced the rear wheel bearings as one of the bearings was busted. The next summer the wheel was loose again and I bought All Balls bearing set and swapped them my self. Now one year later the tire is loose again.... Something with the part assembly? sizes? I took extra care to not hammer the bearings in And the shop I took it earlier was the official Honda repair at my city.

So today I took the wheel apart again to change the tire and to take a closer look at the bearings. I turned a mock-up bearing from plastic that fits snugly on the axel and the bearing slot. Then I pushed the mock-up bearing with the axel and spacer on it and measured from the other side if the bearing grooves matched. They did did not, the spacer was 0.5...1.0mm too long.

space.jpg
A poor picture trying to show the excess length (light is shining behind the ruler as its pressed against the spacer).

I didn't write it down but I think the spacer was exactly 143.00mm or 134.00mm measured with my 10€ caliper. I can check later if someone is interested.

Would be awesome if anyone had any input on this.

I don't know what the length is supposed to be off hand, but it is supposed to be longer, similar to what you are seeing. You need to download the manual, unless you have one already. I think it has the procedure for installing the bearings. Install one at a time. The first one (can't remember if right or left) gets seated all of the way in against the lip in the hub. When installing the second one, you pull it in until the inner part of the bearing pressed against that inner spacer, then stop. If its pressed too far, the load on the bearing won't be centered and it will wear out faster.

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Hmm, makes sense. But It's weird that the manual does not mention this at all. It usually has very detailed instructions. Maybe I'm looking at the wrong place.

bearing.jpg

Hmm. I was going from a different bike I'd worked on, but assume it is similar for most. I'll take a look myself if I get a chance. Was hoping someone smarter than me would chime in and clarify or correct what I'd posted.

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This is exactly right. There's only a "bearing cup" or whatever you want to call it on one side. You bottom out the first bearing in that cup, and then the other bearing is bottomed out on the spacer.
Have you checked/changed the cush drive bearing? Just a thought if that one was chowdered but you keep changing the wheel bearings it could be causing a problem.
What are you torquing your axle nut to? The spec'd torque is known to be too high and could be contributing as well.

Thanks for confirming. In looking at the manual, I verified that the right (as seated on the bike) bearing should be the first one installed for both the front and rear hubs.

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Thanks for all the replies.

I'll try to remember to take pictures, but I'd argue there are similar shoulders on both sides where the bearing could bottom out.

I changed all of the bearings last time, I used the All Balls bearing set with 3 bearings. The cush drive bearing felt good last time but I changed it anyways.

I tightened it by hand. Not too tight, but to the point you can feel it tighten exponentially and then couple degrees over. Compared to the 93Nm from the manual I tried recently, I'd say it was less.

Either way, I'm gonna do the right side first and then bottom the left side on the spacer. Hopefully it will last longer this time

Right side
right_side.jpg

Left side
left_side.jpg

But finally
done.jpg

I got my bike stock, neglected at 8000 miles. The right hand rear bearing had failed. I replaced both wheel bearings with OEM bearings. These I repacked with grease before installing. I felt there was very little grease in them and they would fail prematurely as a result. The worn bearings I took out also had almost no grease left in them, what was left was hard and stiff. I also repacked the sprocket carrier bearing. Bearings are easy to repack with grease.