Renewing steering bearings

[cold_gin]

I'm about to replace steering head bearings on my Cb650. But...

1. I cant find away to remove the lower cone (the one that sits on the steering stem with a dust seal beneath).. Any ideas how I should remove it?

2. Also. It looks that my steering stem is bent. I have attached a picture where I have fixed it in a vice with a lamp under ... would gladly appreciate your advice on this.

bent or not? And how to remove that lower cone?

styrstam.jpg (152.93 KiB) Viewed 7501 times

3. When I removed the lower cup from the frame I accidently made a scratch inside the frame... it's about 1 mm deep and runs like a half circle inside the area were the cup, beads and dustseal is supposed to sit. Any comments on this?

Would gladly appreciate your advice, thougts and comments on these questions.

[Volker_P]

1. Depends if you want to have it off in one part or not. It is a bit hardened, which means saw will be difficult, but one e.g. may weaken it by grinding down and crack it in the vice then. Be aware that the steering stem diameter is larger at the bearing position, so don't grind too deep! In one part is more difficult.
2. One may leave it as it is or find some steel rod that fits in perfectly to fix it with wood into the vice. Then another rod at the other side and bend it back. If it should not work like that, there is still the proven jack method.
But never give force on the triple trees! In any case have a close look at the alumina parts for possible cracks before you install it again. They may fail some time very much later when you don't think of that any more.
3. If later no rollers will run on it directly, no problem. You may remove a possible bur.

[cold_gin]

Thank you for your quick answears!

I think I will go for the easiest method... i.e. Leave the steering steem as it is! But when looking at the picture again, it seems the stem is bolder in the middle part. Do you thing there will be a problem installing the new lower bearing due to this?

BTW. I talked to my Honda dealer today regarding new bearings. It seems that the open type bearings (cup, cone and rollers) is replaced by closed bearings. It might be harder to install but ... much more reliable!

[Volker_P]

No problem. It will be even bolder the last say 8mm (see my comment to 1.). Due to that have a close look before you start grinding in case you'll try that! For installation this means it will fall through and you'll only have to press it on the stem these last 8mm or so.
Best type for steering bearing is tapered roller bearing. Could imagine this is also advantageous in case of a bent stem (nonparallel bearing surfaces). Might be not available at Honda, however. Check out aftermarket, I think there is a good chance to get better bearings for the Honda ball bearings price.

[pae]

The bearing location is a larger diameter then the main stem, so, as Volker says, You only need to fit the bearing over the last few mm's. You can just make out in this picture where the stem widens just above the lower race.



To get the lower race off, you can pull the rubber seal out and over the lower race (the seal is very pliable) and I used an old screwdriver to drive in between the underside of the lower race and the top of the yoke. The lower race should, fairly easily, move up and you can lever it up to free it from the part of the shaft it locates on. It's not difficult to get it off once you start to move it.

Taper rollers are much better. David Silver and Wemoto both stock them if you want to order from the UK.

Phil

[cold_gin]

thank you for the advice! I'll try it first thing after work tomorrow.

[cold_gin]

Removed the lover cone! I've also obtained tapered rollers in a kit (pirate) maded
for cbs 400 - 1000 and some more models... now I need some advice.

1. In my kit there was a replacement for the washer and dust seal. The new solution consists merely of a washer and seems to need some help from a hammer (and a tube or something) in order to be installed. THis makes me suspicious, is this washer really made for CB650? Which one should i choose?

Which soloution should i choose? The new or the old one?

which washer.jpg (36.12 KiB) Viewed 7439 times

2. In order to install the lower cup in the frame i've been thinking about using a glide-hammer with another, larger, cup on it. Is it a good way? Or do I risk breaking anything? (I'm a little bit worried over the thin edges of the cup, is there a chance that i will "open up" the bearing cup?)

Is this a smart, or a stupid way to install the lower cup?

a good way.jpg (30.18 KiB) Viewed 7439 times

Close up of my "cup-and-glide-hammer- solution".

the cone and the tool.jpg (41.81 KiB) Viewed 7437 times

Thank you very much for all your good answears so far.

[Volker_P]

For the washer, measure thickness and outer diameter and compare with the old one. If not exactly equal, possibly the distances won't fit and the bearing won't move free then. I would not hesitate to open the washer a bit with a file instead of deforming it with a hammer, but work very carefully to keep the bore centered perfectly.
If it came out in acceptable shape and spaces look feasible, I'd try to reuse the old dust seal. Probably better than none.
First check out if the seat in the frame can be cleaned out or even has a feelable seam. This would be something to remove before. Then measure seat depth and compare with the new cup cylinder height to be sure it can go in completely. Might be hard to check later if it is a close gap.
I probably would just hammer in the lower cup with a piece of not to hard wood and a hammer. For your method one may drill a hole in a flat piece of rubber/plastic (e.g. old tire tube) and use it as a soft washer to smoothen possible load peaks a bit. This cup should be hardened. Means it should survive or crack, I think visible open up would be a hint to poor quality.

[cold_gin]

For the record. Due to my poor english there has been a missunderstanding. The thick washer is not a washer. It's a spacer. The old rubber seal and washer is supposed to be removed and replaced by this spacer.

This information was given to me on a swedish CB750 forum. But as the steering look almost the same (and the kit I have bought is for CB:s up to 1000) I am convinced this is advice correct.

Anyways, I will post here and tell you how everything went.

[cold_gin]

Don't do as I did

The spacer has an insufficent radius... meaning without the original washer, the stearing bearing is left with no protection from dirt beneath whatsoever. Now i will try to uninstall everything and test with the original washer and dust seal.

[cold_gin]

There is a big discussion out there regarding the dust seal... Some say you manage fine without any protection because the steereing never rotate more than 180 degrees. Some claim that without dust seal your new bearings soon will have to be replaced again...

I went for the latter. What I did is what Volker recommended in the first place. I.e. used the old seal and washer and didn't care about the new spacer. The height is almost the same so it shouldn't matter. The trick is to get the old dust seal centered as there is no longer a lower cone who does this.

Important note 1: There are two versions of steering bearing's kit for our bikes. One japanese version with bearings and spacer. One from a company named Timken that is delivered complete with new dust seals.

Important note 2: David Silver is supposed to sell a dust seal that is designed for the japanese kit.

[Volker_P]

Thanks, that's interesting info!