CB550 F2 1978 Rear Wheel Spacing

[Neilw]

When i originally took the rear wheel off, the photo i took showed two spacers on the right side of the axle rod.

Which when i looked at it looked a bit strange. The parts manual doesn't show a second spacer, but without it there is a gap.

I've fitted one of the spacers to the left and one to the right, but i don't know if this is correct.

I'd love some advice as the wheel doesn't look central in the swing arm or against the botton of the rear mudguard.

Was the original setup the correct one with the two spacers on one side?

Cheers
Neil.

   

[McCabe-Thiele (Ted)]

Definitely not two spacers on the same side on my 500..

Right side is a wide spacer, left side a shorter one.
I found the parts book a good source of checking assembly order.

IIRC the left side spacer should be in the parts book showing the parts for the left side of the drive hub, bearings any seals etc.

Your left side spacer looks as though it's either the wrong one or fitted the wrong way round, difficult to tell from the photo.
My 500 had a wrong sized spacer fitted, an ex-member here Max made me a set in SS of the correct width, I did have the sizes in an old email - now deleted.

If you get stuck PM me and I will give you Max's email address.

[3scs]

It looks like the spacer in your right hand side is maybe the wrong one can you measure how wide it is

[3scs]

Also the spacer that should be touching the left side of the swing arm is the one that comes through the seal that extra spacer shouldn’t be there

[Neilw]

It looks like the spacer in your right hand side is maybe the wrong one can you measure how wide it is

The spacer on the right is 40mm, the one on the left is 15mm.

[3scs]

Is it 40mm or 40mm ish it is hard to measure it built up it should be 36mm that 15mm one shouldn’t be there if you look at the picture of mine the swing arm sits a lot closer to the guard on the rear sprocket

[Neilw]

Is it 40mm or 40mm ish it is hard to measure it built up it should be 36mm that 15mm one shouldn’t be there if you look at the picture of mine the swing arm sits a lot closer to the guard on the rear sprocket

It's 40 mm-ish, more like 39mm, in imperial it is one and half inches.

[Bryanj]

Now i am willing to be shot down but is it the correct swing arm?
There are two different ones and without my stored parts books i cant say which is which.
1 has closed ends where the rear wheel spindle has to be completely removed to get wheel out
2 has removable brackets at the ends so the wheel stays complete to remove

I simply do not remeber which type the F is but i do know the spacers are different, also the brake plate and hub although shoes are the same.

Complete wheel assemblies can be swapped bike to bike but not the individual bits except sprockets

[Neilw]

Now i am willing to be shot down but is it the correct swing arm?
There are two different ones and without my stored parts books i cant say which is which.
1 has closed ends where the rear wheel spindle has to be completely removed to get wheel out
2 has removable brackets at the ends so the wheel stays complete to remove

I simply do not remeber which type the F is but i do know the spacers are different, also the brake plate and hub although shoes are the same.

Complete wheel assemblies can be swapped bike to bike but not the individual bits except sprockets

The swing arm is a replacement as the original was rotten. The replacement physically matches the original and also matches the parts diagram for the F2. It has closed ends.  I assume the original was the correct one for the bike, as it matches the parts diagram.

I've found anomalies in other areas on the bike.

[3scs]

Yes that’s an f2 swing arm with closed ends the k3 is open I think the problem is the brake plate but don’t know anything about any different ones if he takes the extra spacer out and pushes the wheel over the rear sprocket will be nearer to the centre of the chain guard and should be more in line with the front sprocket

[Neilw]

Yes that’s an f2 swing arm with closed ends the k3 is open I think the problem is the brake plate but don’t know anything about any different ones if he takes the extra spacer out and pushes the wheel over the rear sprocket will be nearer to the centre of the chain guard and should be more in line with the front sprocket

Which might explain why both spacers were on the right-hand side when I got the bike.

[Oddjob]

The 550f has the closed end type of swinging arm, the open end arms were fitted to the models with 4 exhausts as you couldn’t remove the wheel spindle to remove the rear wheel for a puncture for example. The 550f also has a slightly thinner o/s spacer than the 500 as well. It has a slightly longer boss on the brake plate to compensate. Your pictures show the wheel completely out of line, the rear sprocket should be almost directly under the chain guard and yours is way off. It wouldn’t run like that, the chain would not be inline enough for it to operate without a severe risk of it coming off. The small top hat spacer you’ve fitted doesn’t belong there. The silver coloured one goes next to the chain adjuster. So why doesn’t it fit? Seems simple if you know both models very well. It looks to me as if someone has fitted a 500 rear wheel in a 550f arm but still tried to use the 550f spacers. Measure the length of the o/s spacer and that should tell us if that’s the case, I think someone bodged it previously just to get back on the road.

[Neilw]

The 550f has the closed end type of swinging arm, the open end arms were fitted to the models with 4 exhausts as you couldn’t remove the wheel spindle to remove the rear wheel for a puncture for example. The 550f also has a slightly thinner o/s spacer than the 500 as well. It has a slightly longer boss on the brake plate to compensate. Your pictures show the wheel completely out of line, the rear sprocket should be almost directly under the chain guard and yours is way off. It wouldn’t run like that, the chain would not be inline enough for it to operate without a severe risk of it coming off. The small top hat spacer you’ve fitted doesn’t belong there. The silver coloured one goes next to the chain adjuster. So why doesn’t it fit? Seems simple if you know both models very well. It looks to me as if someone has fitted a 500 rear wheel in a 550f arm but still tried to use the 550f spacers. Measure the length of the o/s spacer and that should tell us if that’s the case, I think someone bodged it previously just to get back on the road.

The os spacer is about 40mm (between 39mm -40mm).

What can i do? if it's the wrong wheel, that also means it's the wrong hub and brake plate too. What are my options? Will replacing the brake plate with a 550f one do the job, or won't it fit the hub?

[Bryanj]

There are two different hub/brake plate combinations, from memory there is a difference on the outer diameter and i think you can swap one way but not the other just to confuse it.
What you need to do is sort out the sprocet side spacing to get the chain in line then work out what length you need for the other side.
If you want to keep it "standard" easy way is complete rear wheel with axle, brake plate and spacers but to use it safely all you need to do is work out what size spacers you need

[Neilw]

There are two different hub/brake plate combinations, from memory there is a difference on the outer diameter and i think you can swap one way but not the other just to confuse it.
What you need to do is sort out the sprocet side spacing to get the chain in line then work out what length you need for the other side.
If you want to keep it "standard" easy way is complete rear wheel with axle, brake plate and spacers but to use it safely all you need to do is work out what size spacers you need

Removing the left spacer will sort the sprocket side out, and adding it to the right side will give the correct spacing for the wheel. If this makes it usable and safe, I'll go with that option. Longer term, I was going to rebuild the rear wheel with a new rim and spokes, now I'll look for a replacement wheel with the correct parts.