clunking sound coming from new chain

I just replaced the chain and sprockets on my 80 CB750F, and I can't
figure out what's going on with it. I've set the wheel alignment and
chain tension per the manual, and lubed the chain, but I'm getting a
fairly loud clunking sound every time the chain completes a
revolution. I had a similar sound with my old chain, which is the
primary reason I replaced it (thinking it was badly stretched). I'm
stumped as to where the sound is coming from, but it sure seems like
the chain to me. Its very hard to isolate, as it only happens when I
ride, no noises happening with it in gear on the center stand. I'm
wondering if my weight would tighten the chain enough to make it
stressed; the manual specifies chain adjustment should be done using
the center stand. I rechecked the slack while sitting on the bike,
and it seems fine. I also considered a wheel bearing as the culprit,
but I can't really imagine why the sound would be so regularly timed
if that were the case. All nuts and bolts related to the rear wheel
and frame have been torqued to spec, nothing seems to be loose.

Any suggestions?
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1. Check whether one link is a bit tighter than others. If so, it could
cause a sound at higher speeds and none at lower.

2. Check for clearance around the chain. It's possible that vertical or
horizontal clearance is nonexistant under certain conditions. A friend
is helpful here.

3. Carefully examine the chain for wear/rub marks in an unexpected
place. That can help locate the noise, if it's actually associated with
the chain.

4. Could an adjuster have some slop in it?

5. Is your suspension shot?

Ok, that's all I can think of, and the last too seem maybe a bit far
out, but what the heck. HTH

--
Later,
John



'indiana' is a 'nolnn' and 'hoosier' is a 'solkk'. Indiana doesn't solkk.

 

6. Check to be sure you removed the chain-breaking tool

If it's chain related and it is making a loud clunk and only when you ride,
not on the centerstand, it's likely rubbing somewhere. Since you replaced
the chain and sprockets, and the sound didn't change much I think you need
to look further.

 

One kinked link hitting a countershaft sprocket tooth too high would
make the sound you describe.

 

You haven't missed a spacer off, have you, or put one on the wrong way
round? Not likely, but worth checking. A spacer can go on the wrong way
round on my SV1000S, according to a posting on the users' forum.

Leon

 

You might want to pull the axle and drop the wheel. Check the wheel
bearings. I've had the exact sound you describe caused by dead wheel
bearings and ignored them as the cause because they SHOULD have made the
noise every wheel rev and not chain rev. Found it by accident after I
took everything apart to inspect the Cush drive.

--
Gopher Greg
'77 CB750K Stock '78 CB750K AHRMA
'00 ZG1000 Stock '96 Ducati 900SS Former track bike
'01 GSXR750 Current race bike
**********pull 'mychain' to reply***********
("I've abandoned the idea of trying to appear a normal, pleasant person.
I had to accept myself as I was, even if no one else could accept me.
For the rest of my life I would continue to say precisely the wrong
thing, touch people in the raw and be generally unpopular. I had a
natural gift for it" W. F. Temple)

 

First, thanks for the responses - most appreciated!

I found the problem; turns out I didn't mount the chain guard
properly at the front, and it was rubbing on the chain. I'm not sure
why that would result in a regular clunking sound, but apparently it
did and the noise is gone now. I only wish it were that easy to cure
the squealing disc brakes <g>.
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Sandpaper the glaze off the pads and wipe the rotors off with brake
cleaner.

 

Sometimes works, sometimes doesn't.

 

A slight smear of silicone grease (I use ultra-expensive vacuum
grease, because I have access to it...) (or heat-sink-compound) where
pistons meet anti-squeal plates meet pad backing plates _may_ also help.

--
Ivan Reid, Electronic & Computer Engineering, ___ CMS Collaboration,
Brunel University. [email protected][brunel.ac.uk|cern.ch] Room 40-1-B12, CERN
GSX600F, RG250WD "You Porsche. Me pass!" DoD #484 JKLO#003, 005
WP7# 3000 LC Unit #2368 (tinlc) UKMC#00009 BOTAFOT#16 UKRMMA#7 (Hon)
KotPT -- "for stupidity above and beyond the call of duty".

 

Has anyone tried cooking out contaminants in the brake pad on the kitchen
stove set on high?

This trick works wonders for previously deemed shot mountain bicycle disc
brake pads contaminated with grease and oil.

 

Yes, I've often found that they work up until the first pad change,
too. Don't know what dead chicken Suzuki waves to make them effective. I've
actually had the squeal of the rear brake on Black Kat set off a car alarm as
I slowed for my driveway! OTOH Gamma's squeak sure woke up an old duck who
stepped off the footpath in front of me in Vancouver!

--
Ivan Reid, Electronic & Computer Engineering, ___ CMS Collaboration,
Brunel University. [email protected][brunel.ac.uk|cern.ch] Room 40-1-B12, CERN
GSX600F, RG250WD "You Porsche. Me pass!" DoD #484 JKLO#003, 005
WP7# 3000 LC Unit #2368 (tinlc) UKMC#00009 BOTAFOT#16 UKRMMA#7 (Hon)
KotPT -- "for stupidity above and beyond the call of duty".