Topic: CB500 clutch

[Kevnz]

Hi All,
Just working on the clutch on my project 1972 500. Discovered the push rod in 2 pieces, but the short piece doesn't look like it has been broken off the other piece. Checked my other bike and it is exactly the same. One end is slightly dished to accept the small ball bearing in the adjuster, the other looks to be hardened. According to the parts manual, these rods are 1 piece, but I believe they are prone to breaking. Is this piece a factory mod, or an aftermarket thing? They look identical, but appear to be professionally made. Seems odd to have the same thing in 2 different bikes. Any ideas?
Thanks,
Kevin

[bryanj]

Nope, they have been broken by a loose chain.
The rod should be one piece but made of 2 materials originaly, hence what looks like a hardened end

[Kevnz]

Thanks Bryan, thought as much, but the broken ends don't seem to match up, and both bikes have exactly the same thing, and the 2 bits are exactly the same length. But, I guess if there is a weak spot they will all break at the same point.  As a matter of interest, how does a loose chain cause that to break?

[bryanj]

When you roll off the throttle the chain whips and throws just  enough off the front sprocket to hit the pushrod.
You can make a pushrod from the appropriatedia silver steel hardened at the ends, Honda used alloy mix to lighten the rod as the 500 is notorious for slow clutch take up but as nowadays we dont push them quite as hard a heavier rod is ok.
Somewhere on here are the dimensions you need or i do have a nos one somewhere i can measure---no its not for sale!

[Little_Phil]

Very common. My 500 that I got in 2003 was like this, but it had a ball bearing inserted between the break which was the normal bodge and could last for years.
Presume the chain can flap slightly near the sprocket under certain conditions and touch the rod, although I have ever seen any damage there on a rod, just a break at the same point.
I had one made from silver steel as Bryanj describes. CB450 had the same rod, but all steel. Presume the steel/ally rod was to minimise cold to hot change in clutch adjustment.

[jonda500]

Yup, I have two clutch push rods both broken in an identical way - both look like a factory two piece part! - one appears to have likely happened during a chain derailment which also broke the thin metal pushrod guard piece and made an awful mess of the rear sprocket cover.
John

[Kevnz]

Yeah, the ball bearing was inserted between the 2 pieces. When I originally pulled it apart a couple of months ago, I thought I had lost the ball, as I didn't pull the rod. The break seems to be within the tube, though, not where it is exposed to the chain. Have access to replacements, so no problem. Thanks for the advice, Guys, appreciate it.

[jaytee-nz]

Kev - I bought a replacement rod off a guy in Te Awamutu. He had some made in stainless steel and although I've since sold my CB500 it's still local and going well.
Send me a PM if you want his contact details to see if he has any left.
Cheers - JT

[Kevnz]

Thanks for that JT. I know him well; he has provided me with a heap of parts for my project and helped me out a couple of years ago when my previous 500 had jumping out of gear issues I could not resolve. Basically gave me a few sets of gearbox bits so I could mix,n, match. Problem cured. Top bloke. Went over last weekend and got a pile of bits before discovering current issue. Main hold up now is chrome plater; quoted 6 week turnaround back in January; still waiting.

[jaytee-nz]

Yeah, Paul helped me out a lot too (and he bought lots of parts off me that I had left over).
A good man to know !

[Kevnz]

Indeed, I would not have embarked on these 2 projects if he was not around, so helpful. BTW, do you have any idea of what these things are worth now? I will have to sell one to fund the other, but they come up for sale so infrequently, I have no idea what they are worth. Seen some dungers go for ridiculous money, but not seen a good one for some time.

[jaytee-nz]

I sold my one, which was totally restored and had a new set of pipes on it, for $15,000. The purchaser really wanted it then and there as I already had it listed on Trade Me so I think he made me a high offer to secure it.
Prices have definitely increased in general lately though as evidenced by the two CB750's that recently went for $32,000.
All depends on condition and how original they are I think.

[bryanj]

Here in UK an original registered in UK K0 made cose to £10,000 but a US import not as much maybe £8,000.
That is fully restored as original

[Kevnz]

Interesting. Early last year, just before Covid hit, I failed to attract a single bid of $10K on this bike,(green one) a good runner, restored 10 years ago. Sold for $10k after the auction. Just not sure I would recoup the extra $5-6K it would cost to change 1 bike from tidy runner with 4 into 1 , into a mint original. Might just break even, but a lot work for no reward. This how it's looking at the moment.

[bryanj]

The very early ones with the "square" front crankcase are making more

[Kevnz]

Not sure people here are knowlegable, or fussy enough to worry about such things. I've only recently become aware of them, and probably wouldn't recognize one, and certainly of the few bikes I've sold, no-one has ever worried about matching numbers, or things like correct fasteners and the like. So few come up for sale here, I guess if you are too fussy, you will just miss out, or have to resort to restoring one yourself, if you can find one to start with.