CB550 F2 1978 Rear Wheel Spacing

[Neilw]

If the bearing markings match the bearings specified by Honda then AI is wrong. I suspect it’s wrong anyway as the hole in the swinging arm wouldn’t match the bearings either.

Nice few pics by 3scs, the extra holes on the 500 plate are the holes used by the cush rubbers, the 550 used different cush rubbers that didn’t need these holes so were omitted by Honda.

TBH the solution seems fairly easy, just get a spacer either made or try a 500 spacer and see how that goes. Or just use that weird spacer until you find the parts you need.

That's what I'm concluding, but it's nice to understand what I have and what I'd need to do to return everything to standard.

Many thanks for your help.

[Neilw]

The replacement CB550 Brake plate has arrived. It doesn't quite fit, which we knew, but it has confirmed for me that the axle i have is the correct one at 20mm as the plate has a 20mm hole. (Ai was telling me it was 17mm on the CB550 for some reason which got me confused).

The new plate is 15mm higher, which equals the extra 15mm spacer i have for the CB500 hub currently installed.

So my way forward while I'm continuing building the bike is to use the extra spacer on the brake side, until such time that i can source a replacement rear wheel with hub (my wheel is heavily pitted and chrome flaked off). I'll keep the new brake plate to go with the wheel when i get it.

So thanks to all for helping me make sense of what i have a what i need to do going forward.

This bike also has the wrong clocks (too small) and lots of little things that i'm having to fix as i reassemble!

[McCabe-Thiele (Ted)]

A1 is only as good as the data it's been fed with.
The old maxim applies.
Rubbish in = Rubbish out.

Reminds me of the old joke about asking a computer what is the better wrist watch?
One that is irreparably broken, or one that gains a second a day.
Computer says keep the broken one as that shows the right time twice a day.😃

[Robert W]

Interesting.

I am the original owner of a CB500 K1 1972. Also have a 73.
And had a 78 CB550 for parts and didn't notice any difference in the swing arm wheel spacers, but that was 40 years ago.

The spacer on the right is about 45mm in length. Sits against the brake hub which in turn internally sits against the inner bearing race.
The spacer on the left sits inside the bearing /sprocket dust cover and rests against the left side bearing inner race.
BTW there is a spacer tube between the inner bearing races so you can tighten it up without over axially stressing the bearings.

Without removing the wheel or digging in parts bins, if I recall, the left side spacer is about 15mm but not sure but it barel sticks out from the dust cover.

If you really have to know the dimensions, I can dig in my parts bins because I think i have a brake drum axle hub spare.

[Neilw]

Interesting.

I am the original owner of a CB500 K1 1972. Also have a 73.
And had a 78 CB550 for parts and didn't notice any difference in the swing arm wheel spacers, but that was 40 years ago.

The spacer on the right is about 45mm in length. Sits against the brake hub which in turn internally sits against the inner bearing race.
The spacer on the left sits inside the bearing /sprocket dust cover and rests against the left side bearing inner race.
BTW there is a spacer tube between the inner bearing races so you can tighten it up without over axially stressing the bearings.

Without removing the wheel or digging in parts bins, if I recall, the left side spacer is about 15mm but not sure but it barel sticks out from the dust cover.

If you really have to know the dimensions, I can dig in my parts bins because I think i have a brake drum axle hub spare.

Many thanks. I intend ultimately to replace the hub with a stock 550. I already have the correct brake plate in readiness. In the meantime, I'll use it with the additional spacer, which is 15mm.