Mystery Clunk, with vid of chain

[The Magic School Bus]

Howdy,

I need help diagnosing this clunking noise that I first noticed when rolling my bike with the engine off. Decided I would look into it right away since I had other regular maintenance to perform and couldn't immediately identify it.

I have included 3 videos and two photos in this thread, the volume may need to come up to hear the clunk because it is not loud, sorry however about the loudness of the screaming cicadas. I inlcuded pictures of the sprocket teeth and videos of the noise while spinning the wheel, and the other videos are to demonstrate the condition of the chain. I cannot explain this but the location of the clunk noise actually seems to the rear shock but even using the mechanics stethoscope I cannot be certain.

The chain is kept clean and I lube it with DuPont teflon dry wax "chainsaver." There are only about 5k on it, it is the right size chain with the right number of links, and the slack and stretch length are both within spec per service manual and alignment per the string and dowel method featured in the maintenance forum on this site. I have also confirmed that the wheel bearings move freely, the cush drive is in good condition, the front sprocket is not loose and while cleaning the chain very thoroughly, with the wheel removed, using just kerosene and a nylon brush about 300 miles ago, I spun each roller and flexed each link joint to check for kinks or stuck rollers which I have not found.

THE NOISE IN QUESTION and the subtle movement of the chain:

Looking for tight spots:

Inspecting deflection:

 

[GIXERHP]

How old is the chain?
Remove the chain from the rear sprocket, then spin the wheel, to rule out rear bearings and cush rubbers
I really think it s the chain,
Its way too loose, has a lot of side to side movement.
I probably has tight links

 

[AQTCJAK]

Replace both sprockets and the chain and the noise will stop

 

[The Magic School Bus]

the chain and sprockets are only a little over a year old & ~5k mi

 

[Mythos]

the chain and sprockets are only a little over a year old & ~5k mi

Both the front and rear look like they have a noticeable amount of wear. Not terrible but getting to the point where they should be changed. If you use the bike for racing as it appears from your avatar, I can see how that could happen. I get about 10k miles out of an aluminum rear sprocket and 20k miles out of a steel front sprocket and chain doing street riding.

Measuring the chain stretch requires a bit of judgement since it's only about a 16th inch or less across the 21 pins. You should take that measurement as closely as possible and make a decision as to whether the chain is worn out.

Im not sure the clunking is caused by the chain or sprockets even if they are worn. The noise seems to happen every single link. Is the chain getting squeezed against the inside surface of the front sprocket? Mine apparently was. I don't know if it was clunking or not when I rotated the rear wheel. I don't know how long this wear was happening. I did recently attempt to align the rear axle by turning each adjuster bolt all the way in and then counting the number of rotations it took to properly tighten the chain. My adjusters were threaded out an equal number of turns on both sides. Seems that should align the axle perfectly but I'd say it didn't...unless I screwed up when I was counting.

Uneven Wear on Countershaft Sprocket | Maintenance and Do-It-Yourself

I pulled the stock countershaft sprocket off my 08 and noticed it had wear all the way around on the side that faces the motor. The side that faces out doesn't look like it was touched by the chain at all. I had this kind of wear on the rear sprocket of my other bike but the front had no side...

www.hayabusa.org

Another thought: that front sprocket is saw tooth hooked a bit. That's not unusual for these bikes. The hooked teeth might be holding onto the roller as it leaves the sprocket to travel down the lower run of chain. If so, that's just anpother symptom that the sprockets need changing and maybe the chain too.

 

[Dopey]

the chain and sprockets are only a little over a year old & ~5k mi

Have u had the rear tire off recently? I had a similar noise and it turned out to be a missing spacer between the sprocket carrier and rim. It had caused the other bearings to become damaged and had what seemed to be the same type of noise. In my case I put a couple thousand miles on my bike before I noticed it so when I say recently that doesn't mean the last few miles.

 

[The Magic School Bus]

Both the front and rear look like they have a noticeable amount of wear. Not terrible but getting to the point where they should be changed. If you use the bike for racing as it appears from your avatar, I can see how that could happen. I get about 10k miles out of an aluminum rear sprocket and 20k miles out of a steel front sprocket and chain doing street riding.

Measuring the chain stretch requires a bit of judgement since it's only about a 16th inch or less across the 21 pins. You should take that measurement as closely as possible and make a decision as to whether the chain is worn out.

Im not sure the clunking is caused by the chain or sprockets even if they are worn. The noise seems to happen every single link. Is the chain getting squeezed against the inside surface of the front sprocket? Mine apparently was. I don't know if it was clunking or not when I rotated the rear wheel. I don't know how long this wear was happening. I did recently attempt to align the rear axle by turning each adjuster bolt all the way in and then counting the number of rotations it took to properly tighten the chain. My adjusters were threaded out an equal number of turns on both sides. Seems that should align the axle perfectly but I'd say it didn't...unless I screwed up when I was counting.

Uneven Wear on Countershaft Sprocket | Maintenance and Do-It-Yourself

I pulled the stock countershaft sprocket off my 08 and noticed it had wear all the way around on the side that faces the motor. The side that faces out doesn't look like it was touched by the chain at all. I had this kind of wear on the rear sprocket of my other bike but the front had no side...

www.hayabusa.org

Another thought: that front sprocket is saw tooth hooked a bit. That's not unusual for these bikes. The hooked teeth might be holding onto the roller as it leaves the sprocket to travel down the lower run of chain. If so, that's just anpother symptom that the sprockets need changing and maybe the chain too.

Thanks Mythos! The avatar is me on my R6, I do not race my 'busa and in fact am gentle and definitely smooth on it since I plan to keep it forever and tour the western hemisphere with it.

 

[Mythos]

You can drive yourself crazy with axle alignment on this bike. I tried the "screw all the way in and then screw out equal number of turns" method. There are a number of tools to check axle alignment, some pretty spendy. You did the string method. I'd like to do all of them and see how they compare with the axle adjusted the same for each.

My cheapazz red neck method of chain adjustment. | General Bike Related Topics

I just use two threaded rods one in the axle one in the swing arm pivot. It's not because I think the Gillis chain adjusters are inaccurate, it's just easier to do standing up. I can easily get to within less than one MM using a standard tape measure. it'd not my idea I just wasn't willing to...

www.hayabusa.org

 

[Mythos]

Have u had the rear tire off recently? I had a similar noise and it turned out to be a missing spacer between the sprocket carrier and rim. It had caused the other bearings to become damaged and had what seemed to be the same type of noise. In my case I put a couple thousand miles on my bike before I noticed it so when I say recently that doesn't mean the last few miles.

Oh, you mean that sleeve thingamabob in step 4.

Rear Wheel Inspection, Gen 2 Hayabusa | Maintenance and Do-It-Yourself

Rear Wheel Inspection Gen2 Hayabusa 1. Test the condition of the cush drive rubbers by turning the sprocket forward and back by hand. This may be done with the rear wheel installed. If there is any movement in either direction, the cush drive rubbers should be replaced. 2. Remove the...

www.hayabusa.org

I wonder, is there a right way and a wrong way to install that? Will it go in the wrong way? If so, that might have been what caused the unusual wear on my front sprocket. Pretty sure I put that in the right way when I changed my cush drive dampeners. I hope so since I did a tutorial on it.

 

[Dopey]

Oh, you mean that sleeve thingamabob in step 4.

Rear Wheel Inspection, Gen 2 Hayabusa | Maintenance and Do-It-Yourself

Rear Wheel Inspection Gen2 Hayabusa 1. Test the condition of the cush drive rubbers by turning the sprocket forward and back by hand. This may be done with the rear wheel installed. If there is any movement in either direction, the cush drive rubbers should be replaced. 2. Remove the...

www.hayabusa.org

I wonder, is there a right way and a wrong way to install that? Will it go in the wrong way? If so, that might have been what caused the unusual wear on my front sprocket. Pretty sure I put that in the right way when I changed my cush drive dampeners. I hope so since I did a tutorial on it.

U had it right or only fits properly 1 way

 

[Berlin Germany]

to me it sounds like a demaged roller bearing

1st guess - at the outlet shaft in the gearbox´s wall behind the front sprocket
eventually caused by a too tight tightened chain.
the in the video shown slack for me is a bit too little.
should be around one inch (20-30 mm)

how to find out?

gear in neutral
dismantel the side fairing,
pull off the sprocket cover
loosen the rear wheels axle and push the wheel to the front
lift the chain off the front sprocket
and disassamble the sprocket
then turn the (outlet-)shaft by hand in very silent surroundings

if then the sound comes up - congrats

- the motor has to be opened and the bearing has to be replaced by new
means around 15-20 h

&

 

[The Magic School Bus]

to me it sounds like a demaged roller bearing

1st guess - at the outlet shaft in the gearbox´s wall behind the front sprocket
eventually caused by a too tight tightened chain.
the in the video shown slack for me is a bit too little.
should be around one inch (20-30 mm)

how to find out?

gear in neutral
dismantel the side fairing,
pull off the sprocket cover
loosen the rear wheels axle and push the wheel to the front
lift the chain off the front sprocket
and disassamble the sprocket
then turn the (outlet-)shaft by hand in very silent surroundings

if then the sound comes up - congrats View attachment 1640783 - the motor has to be opened and the bearing has to be replaced by new
means around 15-20 h

&

Chain slack is actually at 34mm in the video I just loosened it up a little extra just to see how many people would say it looks too tight haha got a ton of people on facebook who also see that somehow. No worries though, thanks for the input on the output shaft!

Everyone thanks for your help it turns out the front sprocket wear pattern was causing the teeth to ever so lightly pluck on to the chain as it left the sprocket. If you look closely at the pictures you can see the deformation of the teeth on one side.

 

[Berlin Germany]

@The Magic School Bus

the clunk clunk sound of the video , as far as i know, can not caused by a the chain while touching / lill bit scratching the sprocket.

as to see you seemingly pulled the sprocket - did you turn slowly the shaft by hand to control the bearing in the gearbox´s wall ?

 

[Mythos]

Everyone thanks for your help it turns out the front sprocket wear pattern was causing the teeth to ever so lightly pluck on to the chain as it left the sprocket. If you look closely at the pictures you can see the deformation of the teeth on one side.

BINGO! Hope that was truly it. Order a new front sprocket for $20 and that will tell. I would sure try Berlin's test to though.

LOL 15 to 20 hours? ...not for me. 15 to 20 months maybe.

 

[Mythos]

Vortex hey... ? I had that on my other bike for about a thousand miles so I can't give much of a review. Do some research to find out if they're known to wear out quickly. I got a Renthal for my busa. Still have not installed it.