Topic: Mysteries of the CB500 Clutch...REVEALED!

[Master Ted]

Link is the order page.

[bryanj]

If you cant get one over there i just bought several in among a job lot, email me direct if you get stuck

[Einyodeler]

If you cant get one over there i just bought several in among a job lot, email me direct if you get stuck

If you`re talking about new replacements, would it be possible to get the correct length measurements from yours? I have a few used ones but all pretty worn down, so I`m planning on milling a few myself.
 
One other thing with the 500 is you can not run the 18 tooth front sprocket to lower your revs as on the 550 because the chain will snap that rod. There is barely any clearance with the chain tight .

[canttuckmyshirt]

Try:
http://www.servicehonda.com/parts.php

Part# 22850-323-000

$23.86 USD

I have already called them and a bunch of other parts dealers. Honda no longer has these (at least in the states). I would also be willing to make new rods, but I need dimensions..

[bryanj]

OK here we go,
I  also have a late replacement which is an all steel rod, gold pasivated (to stop rusting) same part number.

Problem is all my micrometers are packed for a move so i cant be exact on diameter---I think its 8mm; Length is 256mm overall with one end flat and the other a half round.

Hope that helps all
Regards Bryan

[puppytrax]

...diameter---I think its 8mm; Length is 256mm overall with one end flat and the other a half round.

Mine is back together, and I didn't measure it...   

But I did notice that each end is hardened...so a replacement rod made of drill rod would be a good idea (properly hardened & annealed)...   

[number13]

I've been meaning to get back to this thread, thanks for reviving it Kevin400F!
Attached are some pictures of my modified push rod. I lucked out and found
a NOS pushrod on e-bay, got it cheap and, before installation, I made a collar
for the lifter end. This keeps the end of the rod centered on the throw-out
bearing. I am pretty sure the clutch rod self destruct sequence begins there,
when the push rod wears and begins to settle eccentrically on the bearing.
When that happens it is certain to begin whipping each time the clutch
is used and complete snapping is certain.
First pic shows the collar made from an old piece of aluminum tubing.
Second pic is the collar fitted and filed smooth. It is a friction fit, though I suppose you could epoxy it in place.
Don't weld or braze as that would ruin the hardened end.
Third pic shows the completed rod.
Fourth pic shows the rod installed. No clearance issues at all.
I have been using this push rod for about 6 months now, no problems
and the action is very smooth.

[canttuckmyshirt]

Just got my new clutch rod.... Does any one know why the center portion of the rod is made of aluminum tubing? The rod is made of at least 4 individual pieces pressed together. What is the flat material pressed in, opposite of the ground and heat treated end (in that order. not heat treated and ground)?

I'll post an update as soon as I get a chance to cut apart my old unit.

My plan is to take some dims and make a sketch, but I don't yet fully understand all of the design features.

[Master Ted]

Just got my new clutch rod.... Does any one know why the center portion of the rod is made of aluminum tubing? The rod is made of at least 4 individual pieces pressed together. What is the flat material pressed in, opposite of the ground and heat treated end (in that order. not heat treated and ground)?

I'll post an update as soon as I get a chance to cut apart my old unit.

My plan is to take some dims and make a sketch, but I don't yet fully understand all of the design features.

Where did you get your part?

[canttuckmyshirt]

Where did you get your part?

From bryanj  (see page 2 of this post). Once I sketch the part up, we should be able to get it made at any small machine shop.

[crazypj]

Just got my new clutch rod.... Does any one know why the center portion of the rod is made of aluminum tubing? The rod is made of at least 4 individual pieces pressed together. What is the flat material pressed in, opposite of the ground and heat treated end (in that order. not heat treated and ground)?

I'll post an update as soon as I get a chance to cut apart my old unit.

My plan is to take some dims and make a sketch, but I don't yet fully understand all of the design features.

Yes.
Alloy expands at about 6 times the rate of steel.
When engine gets hot the lifter mechanism effectively moves away from the pressure plate.
Using alloy in pushrod means it expands closer to same rate so clutch doesn't drag as much when hot, particularly if adjustment isn't quite right.
PJ

[jreich]

Reviving an old post here, as I'm a bit stuck with the clutch operation on my 72 500

I've completely torn apart the clutch lifter mechanism; the lifter sleeve and lifter are in good working order

I've got the clutch lever set correctly, and just replaced the ball-bearing within the lifter mechanism, however the clutch still will not engage

With the left-side cover off, when I pull the clutch lever, I get the correct action from the clutch actuator

What type of movement should there be in the clutch rod?

I'm currently getting no in/out movement, if that is the movement I suspect should be happening

It is in one piece, and is 10 inches long.

I can shift into gear

At this point, if the clutch will not engage, should I rebuild the basket?

Thanks in advance!

Cheers!

[bryanj]

Hi do you mean the clutch will not slip or not grip? Email me direct at BLJ@BLJ.org.uk and i will try and help out

[number13]

Hello All -

Just wanted to add something to this old thread, and that is a
recently discovered enemy of smooth clutching, drag bars.
I have been using drag bars for about a year now, but was still
experiencing a very heavy clutch. It actually worked smoothly, but
was very stiff and made my wrist hurt after an afternoon's ride.
The problem disappeared after I switched to some wider low rise
bars. The main problem was the sharp bends the clutch cable
had in it. So, if you must use drag bars, shorten your clutch cable,
your wrists will thank you.

[nikbristow]

I know this thread is several years old but since we're dealing with a part that was discontinued back in 2007 and is still discontinued in 2011 I wanted to add what I think is useful information. The early 70s CB450s used the same clutch push rod as the CB500, at least according to a part number search I did. As of this writing, CB500 clutch push rods are pretty much impossible to find anywhere, but there are four CB450 clutch push rods on ebay. I foolishly bought the first one I saw cause I was so excited and then later found 3 more that were $10 cheaper. Hope this helps.

[Shifter19]

Ok guys,  I understand this is an old thread, but I find myself in need of this clutch rod. And sure enough, they're pretty rare. There's a couple on Fleabay for $50 bucks apeice but I'm more inclined to make my own. The one that came out of my cb500k2 is broke in two and one end looks like it may be somewhat collapsed. I have no idea how long it's supposed to be. So my question is this....has anyone definitively measured this rod for length?  If so, could you PM me or post the exact length?

Thanks

[TwoTired]

Please post the dimensions of the rod in this forum.

Thanks,

[number13]

I'll get on that tonight, check back tomorrow!

[number13]

Measurements for a Honda OEM pushrod are:

10 1/8 inches or 25.7 cm long
3/8 inch in diameter or 9.5 mm

You can easily fashion a push rod from
3/8" steel rod found at any hardware store.
The shifter side end should be ground flat and square,
and the brake side end should be neatly rounded in a semi-sphere
to mate with the clutch basket. If you err, err on the side of a bit too
long since this will allow you to keep the lifter mechanism low and avoid cracking.
May also be a good idea to quench harden the ends.

[SteveD CB500F]

I'll copy this to the Tricks&Tips if you don't mind.  Good info.

[DavePhipps]

YAY now I can make one!!!!!!

[TwoTired]

Thanks for that number13.

Hardening the ends almost seems like a requirement for longevity's sake.

Might also look into case hardening.  This adds carbon to the outer surface of the steel, Kinda like cladding hard steel onto ductile steel.  Hardened steel tends to crack.  But, if the core of it can bend without cracking, you have a more durable rod.  If the outer surface is very hard, it takes a lot to wear into the steel.

Check out "Kasenit", or case hardening.

Cheers,

[Lavis500]

So I was browsing through threads, silently learning, and I stumbled upon this informative piece!  After reading it, I went to the garage to glance over my parts, and as I was holding my clutch adjuster (also broken in the very same place) a thought occurred to me.  Is there anything preventing someone from simply brazing the pieces back together and grinding it down to be smooth?  It doesn't appear to be a terribly precision piece (with the exception of the internal threads which should be kept clear), so as long as the seal can be placed back on top, why can't this be repaired?  Even if you weren't lucky enough to have all of the pieces, could you not fill in the whole with braze and grind it down?

Surely I'm not the first person to think of this??

[number13]

It is made of aluminum or similar alloy, so brazing
won't work. I'm not sure you could repair it, but I always
thought a clever person could simply replace the mechanism
with a ball and ramp style lifter. Honda used such a mechanism
on later models. At least one forum member has installed a
hydraulic clutch.

[DavePhipps]

I think TurboGuzzi made his own mechanism for his 500 race bike. You might PM him.