Something I've noticed recently.

[lucky_1_chris]

While coasting in 2nd, 3rd, 4th, and 5th, with the clutch disengaged, slight blips of the throttle causes a clunk. It's not a hard clunk. It sounds like, and it comes from the same area as a shift clunk, but not as hard or loud as a shift. The clunks only happen between certain MPH ranges, and it changes between gears. I can produce a clunk in 3rd between 20 and 30ish mph, 4th at 25-35 ish, and so on. No clunk in neutral, clutch in or out, even if the bike is rolling. ONLY in gear and rolling. I can also produce the same clunk in 1st if I start to take off then pull the clutch after the bike has started moving, or if I start to accelerate in 1st then need to pull the clutch to stop. (Think easing up, or pulling up to the exit at a gas station.)  It doesn't do this every time in this scenario, but it's always done it often enough in 1st since I've owned it that I've considered it normal.

It may have always done this, but I only noticed it a few weeks ago. I usually blip the throttle a bit when downshifting, and I heard it the first time while blipping the throttle to downshift in the parking lot at work but had to pull the clutch and stop (from 3rd gear) when a truck started to pull off the dock. After hearing it, I circled the parking lot a few times to try to reproduce it. I found that it clunks just as I blip the throttle, and clunks again, though not as loud, just as it returns to idle. Again, this is only while rolling, and at a different MPH range depending on what gear I'm in. Also, in the last several thousand miles I've developed a shudder when taking off in 1st after the bike is warmed up. Nice and smooth when cold, only shudders after it's warmed up a bit. I hope the problems are related...

I've got a weekend trip coming up this month, and I'm gonna rebuild or replace the slave cylinder to see if it solves the shuddering-while-taking-off problem. (The bushing in the clutch handle if perfect.) If not, then it's a new clutch. My question is this: If the clunking continues after clutch problems are ruled out, what could possibly cause the clunking?

I hope this makes sense. Thanks for the input.

Chris

[Patrick]

The 'clunk' in the drive-line is just 'slack' in the system,, especially if the drive dampers are worn..
The 'shudder' sounds like sheared clutch rivets..

[lucky_1_chris]

The 'clunk' in the drive-line is just 'slack' in the system,, especially if the drive dampers are worn..
The 'shudder' sounds like sheared clutch rivets..

I hope that's all it is, but I don't understand how blipping the throttle could take up slack if the clutch is disengaged.

The clutch has been acting up for a little while now. It'll be fixed soon.

[Ricky-D]

If you are having clutch problems as you say, then it is just like Patrick says.

There;s probably enough clutch drag to facilitate the slack take-up even though the clutch lever is fully depressed.

Clutch work will not affect the drive line slack whatsoever.

There is more to drive line slack than just the dampers in the rear wheel tho!

***

[lucky_1_chris]

If you are having clutch problems as you say, then it is just like Patrick says.

There;s probably enough clutch drag to facilitate the slack take-up even though the clutch lever is fully depressed.

Clutch work will not affect the drive line slack whatsoever.

There is more to drive line slack than just the dampers in the rear wheel tho!

***

My initial thought was that the clutch isn't fully disengaging letting it bite a little, or that it's dragging due to a failing clutch.

Are you saying that the clutch is dragging cuz it's on its way out, or that even with a good clutch there's enough drag to take up the slack?  I was thinking that after I replace the clutch it wouldnt drag enough to take up the slack, so if the clunk remained then it was something other than slop in the line. I guess this may not be the case.

This is a pretty loud clunk. If the clutch is dragging more than it should, maybe the clunk is harder/louder than ordinarily would be?

[Ricky-D]

For me, I feel that if the clutch is dragging, it should be easily recognizable by the rider.

A test that can be performed easily, that will reveal a dragging clutch is this:

Sitting in neutral with the motor running you can hear all the rotation of the gearbox with the clutch lever released.   Actually there have been many complaints by riders about this noise and if there is a problem.

So, while sitting there under this condition, you pull the clutch lever fully in and the rotational noise goes away I would say you do not have a dragging clutch.

This is not the definitive test for sure, but it surely indicates the clutch is disengaging to  a point where the internal resistance in the transmission from friction and oil is stronger than the remaining friction in the disengaged clutch.

Another easily testing method to determine if the clutch is dragging excessively is the ease to which you can shift the bike into first gear and then out of first gear back into neutral.  All this with a completely stopped bike. A dragging clutch can make this a difficult thing to do, especially trying to find neutral from first gear.

***

[lucky_1_chris]

For me, I feel that if the clutch is dragging, it should be easily recognizable by the rider.

A test that can be performed easily, that will reveal a dragging clutch is this:

Sitting in neutral with the motor running you can hear all the rotation of the gearbox with the clutch lever released.   Actually there have been many complaints by riders about this noise and if there is a problem.

So, while sitting there under this condition, you pull the clutch lever fully in and the rotational noise goes away I would say you do not have a dragging clutch.

This is not the definitive test for sure, but it surely indicates the clutch is disengaging to  a point where the internal resistance in the transmission from friction and oil is stronger than the remaining friction in the disengaged clutch.

Another easily testing method to determine if the clutch is dragging excessively is the ease to which you can shift the bike into first gear and then out of first gear back into neutral.  All this with a completely stopped bike. A dragging clutch can make this a difficult thing to do, especially trying to find neutral from first gear.

***

Rotational noise goes away. Neutral is easy.

Other than wheel damper, what could be the cause of excessive slop in the line. Under the conditions in the OP, will your bike produce the same noise/clunk?

[Ricky-D]

Other than wheel damper, what could be the cause of excessive slop in the line. Under the conditions in the OP, will your bike produce the same noise/clunk?

no special order:

transmission
universal joint
pinion cup and drive shaft
pumpkin
drive splines & flange
wheel dampers

I am not too interested in trying your test.  I don't think you have a problem here!  The transmission is clunky pretty much.

First thing I'd try is changing to a different oil to solve the shuddering problem.

***

[lucky_1_chris]

Other than wheel damper, what could be the cause of excessive slop in the line. Under the conditions in the OP, will your bike produce the same noise/clunk?

no special order:

transmission
universal joint
pinion cup and drive shaft
pumpkin
drive splines & flange
wheel dampers

I am not too interested in trying your test.  I don't think you have a problem here!  The transmission is clunky pretty much.

First thing I'd try is changing to a different oil to solve the shuddering problem.

***

Oops...I misread your post earlier. Disregard my previous response... That's what I get for reading and posting from my phone.

I'm sure that response made no sense whatsoever.   Thanks for the advice.

[lucky_1_chris]

Thanks Patrick and Ricky. I'll not worry about it unless it gets worse...

Of course, I said that after I noticed it, too... I'm sure I'll still worry about it. 

Thanks, y'all.