Topic: 76 CB550 Cafe build

[tshrey]

Anyone every had chatter in their clutches?  Leaving a stop I've had a couple instances of a very unpleasant sound, not a grinding but almost like the clutch basket is wobbling a tiny bit and generating a weird resonance.  It goes away once the clutch is fully engaged and only does it leaving a stop.  I don't think this happened before I put used stock clutch springs back in.  Going to pull the cover off and make sure something isn't loose in there.

[flatlander]

i didn't have this issue but when i converted mine to 7 disks i learned that keeping the stack hight very close to stock is really important.
there's also a spacer under the circlip making sure there's not too much play.

[Godffery]

Anyone every had chatter in their clutches?  Leaving a stop I've had a couple instances of a very unpleasant sound, not a grinding but almost like the clutch basket is wobbling a tiny bit and generating a weird resonance.  It goes away once the clutch is fully engaged and only does it leaving a stop.  I don't think this happened before I put used stock clutch springs back in.  Going to pull the cover off and make sure something isn't loose in there.

What type of Oil are you using? 
If it's a common automotive (not formulated for wet Clutches) it can cause the plates to slip a bit, so the chattering could be them slipping and trying to re-grab.

[tshrey]

Genuine Honda 10w40 dino oil.  I'm going to measure the thickness of everything tonight, maybe that thrust washer is worn or something.

[tshrey]

So I think first of all, it was just poor assembly on my part; I found the circlip not home so that could let the basket move outboard a little bit and I could imagine if the basket would start bouncing in and out a tiny bit that would do what I was feeling. 

But after measuring everything I noticed that the wear limit on Honda friction discs is 3mm; all of my Barnett discs are 2.7mm to start.  .3 x 6 regular friction discs means my stack is almost 2 mm shorter than what Honda calls for.  I don't have the thicker riveted 'damper ring' that the later model units had but I think I might try to find one, that would make my stack height the same as stock.  Would this slimmer height also mean when I pull the clutch lever in I have to compress the springs more?  Maybe that is why my clutch pull always felt heavier than I thought?  I don't have a good visual model in my head for what that assembly is doing.

[Godffery]

So I think first of all, it was just poor assembly on my part; I found the circlip not home so that could let the basket move outboard a little bit and I could imagine if the basket would start bouncing in and out a tiny bit that would do what I was feeling. 

But after measuring everything I noticed that the wear limit on Honda friction discs is 3mm; all of my Barnett discs are 2.7mm to start.  .3 x 6 regular friction discs means my stack is almost 2 mm shorter than what Honda calls for.  I don't have the thicker riveted 'damper ring' that the later model units had but I think I might try to find one, that would make my stack height the same as stock.  Would this slimmer height also mean when I pull the clutch lever in I have to compress the springs more?  Maybe that is why my clutch pull always felt heavier than I thought?  I don't have a good visual model in my head for what that assembly is doing.

With 2mm less overall, then there would be less preload on the springs.

[tshrey]

@flatlander I followed your clutch odyssey.  You mentioned in one post the 78 basket is a little deeper.  If the 78 is when they went to the wider top friction disc then the basket in my bike is a 78, so I have even shorter stack height for that basket.  I found an entire 78 basket in good shape on fleabay, will try that out when it gets here.

[flatlander]

ha, you found that thread? it was quite a puzzle

i think if you have the later basket that went with the wider disc then indeed, you may need more height to get the correct amount of free space. to be honest, i think the stack needs to be more than 2mm short to cause rattle but adjustment with the screw on the outside of the cover will become difficult to impossible with incorrect stack height as the adjustment range itself is only about 2mm.

the problem is that many aftermarket kits, and also many sellers of OEM parts don't necessarily understand the different specs between clutch discs and plates of different CB models, let alone different versions of of the same model. i ended up ordering just a few different parts to mix and match until i got the height i needed.

[tshrey]

I have about 4mm of gap at the top (between top steel and the wider friction disc) as it sits.  That seems excessive.  But short of this new resonance/almost grinding sound I've never had an issue other than what seems like a pretty heavy pull (but Godffery said that should make it easier, not harder).  I guess we'll see in a couple days.

[Godffery]

I have about 4mm of gap at the top (between top steel and the wider friction disc) as it sits.  That seems excessive.  But short of this new resonance/almost grinding sound I've never had an issue other than what seems like a pretty heavy pull (but Godffery said that should make it easier, not harder).  I guess we'll see in a couple days.

Yes, technically with less preload on the springs, that should result in a softer lever pull. (Unless you have heavy duty or longer springs)
So it is possible that the shorter stack is not allowing stock springs so supply enough pressure to prevent slipping?
 As for the hard lever pull;  If the cable is routed in a way that puts too tight of a curve on it, that could cause it.  Or perhaps even just a cheep cable with no nylon inner coating? 

[tshrey]

Never had any slipping issues, what I'm feeling is what I would call noisy chatter in a car.  I'm guessing I fixed it my actually getting the circlip in its groove, but I haven't ridden the bike since then.

The pull definitely got better after going to stock springs and an OEM Honda cable.  Even if I remove the handlebars and take all the curves out of the cable the resistance doesn't change, so I don't think it is my routing.

[Godffery]

Never had any slipping issues, what I'm feeling is what I would call noisy chatter in a car.  I'm guessing I fixed it my actually getting the circlip in its groove, but I haven't ridden the bike since then.

The pull definitely got better after going to stock springs and an OEM Honda cable.  Even if I remove the handlebars and take all the curves out of the cable the resistance doesn't change, so I don't think it is my routing.

Well, that is a bit of a mystery then.!?

[grcamna2]

The plates are the Barnett thin racing(red?)clutch plates? I know they're set up to give holeshots and I noticed them chattering if I tried to do easy street riding & smoothly let the clutch out like I did with OEM stock clutch plates.
Try taking-off with a lot of power and see what they do,and power-shift through the gears:I think you'll find the chattering will go away.. I like running OEM or Vesrah plates(comparable quality to OEM for less $)for street riding.

[SOHC4 Cafe Racer Fan]

I had some slipping with my 836-kitted 750 (ported head, cam, CRs), on hard-load acceleration it would sometimes slip and the revs would run away.  I seemed to fix it by moving to heavy duty springs.  I mitigated the pull with a ball-bearing clutch perch.

[tshrey]

I certainly didn't buy racing plates on purpose, I thought I just got a regular replacement kit.  That doesn't me I didn't, maybe that is the issue.  Hopefully this all goes away tomorrow when I get the new clutch basket, it is supposed to have stock plates in it.

[tshrey]

I had some slipping with my 836-kitted 750 (ported head, cam, CRs), on hard-load acceleration it would sometimes slip and the revs would run away.  I seemed to fix it by moving to heavy duty springs.  I mitigated the pull with a ball-bearing clutch perch.

You happen to know which perch you got?

[SOHC4 Cafe Racer Fan]

I had some slipping with my 836-kitted 750 (ported head, cam, CRs), on hard-load acceleration it would sometimes slip and the revs would run away.  I seemed to fix it by moving to heavy duty springs.  I mitigated the pull with a ball-bearing clutch perch.

You happen to know which perch you got?

Pro-Taper universal.

[flatlander]

i'm very happy with my 7 OEM plates and OEM springs. easy and smooth to operate yet strong enough for anything. brent uses a similar setup in his race 550 that, if i remember, has about 70hp? compared to that my street 550 has a mere 56hp and i have no issues or concerns with that clutch.

[tshrey]

The weird chatter sensation was definitely from not having the circlip home.   After that fix I haven't had any issues.  The 78 full stock basket is coming UPS today, so I'll swap that tonight and see how different it feels.

[tshrey]

So the 78 basket feels lighter and more progressive than what was in my bike (before it was very on/off). It also is quite a bit quieter when sitting in neutral with the clutch engaged.

[grcamna2]

So the 78 basket feels lighter and more progressive than what was in my bike (before it was very on/off). It also is quite a bit quieter when sitting in neutral with the clutch engaged.

Did the 78' clutch hub come with some fiber clutch plates ?

[tshrey]

It said it was all stock. So I used the friction disks and steel plates that it came with.

[tshrey]

Just straight up riding the bike now.  Zero oil consumption, did a compression test and got 175 across the board so everything is as healthy as I can measure.  The noise from the valvetrain though is something else.  Now that I have the cone engineering muffler on it, from the seated position the ticking is almost the loudest sound on the bike.  I do no think it is an exhaust leak, used new copper gaskets the last time I put the exhaust on and can't hear or feel any leaks.  The stethoscope test would say the noise is coming from the camshaft end cover on the left side; I have no indication of the ovalling that can happen to these older covers and the valves are all in spec and stay in spec.  I've had the valve cover off several times and see no indication of something amiss.  I made a video, but camera mics just kind of suck.  If I had to pick a frequency range for the sound itself I would say that it is the same sound as when you wiggle the rockers (side to side, perpendicular to their rocking).  Maybe a rocker paddle is a little uneven and it pushes the rocker to one side?

At this point I guess I should just ignore it and ride   Anyone have any thoughts?



Video at the following link:
https://photos.app.goo.gl/kjXNQox4HFwTEMtn6

[grcamna2]

The muffler you have on there sounds nice and quiet. 
The valve train sounds normal to my ears.

[tshrey]

Thanks for both inputs 

I had a cager pull out in front of me today and while the single modern disk is a lot better than what was on there I'm going to stick the second rotor and caliper on the front.  Let's just hope it doesn't make the noodle frame fold when I come down on the binders hard.