Clutch Spring plate poll

[Nibelungen]

Originally Posted by IXL2Relax

Since I had a clutch issue recently (Thread), I decided to check the accumulated statistics from this poll thread - The results:

Spring Plate Failure Poll

>>> Rigid Mount Engine
Upto 50,000mi (84 Resp):
Good = 65 -- 77%
Bad == 19 -- 23%

Over 50,000mi (22 Resp):
Good = 19 -- 86%
Bad == 3 --- 14%

>>> Rubber Mount Engine
Upto 50,000mi (217 Resp):
Good = 106 -- 49%
Bad == 111 -- 51%

Over 50,000mi (22 Resp):
Good = 16 --- 73%
Bad == 6 ---- 27%


The over 50K numbers interest me most - If this problem was a wear issue, wouldn't the failure numbers (%) go up with more miles on the bike, especially after 50K miles?

The poll did not specifically inquire whether the Spring Plate was replaced without it failing - or whether the longer reported miles were after such replacement.

The results (which are, of course, anecdotal only) show most failures before 40K on rigid mounts or 30K for rubber mounts.

I wonder if this failure is related to something other than simply wear,
such as variations in:
mfr quality control?
assembling qc?
riding style?

Very interesting...

IXL _______ >>>> My Motorcycle Chronicles Are Here <<<<

IMHO riding style is paramount

[Tomcatt]

Originally Posted by IXL2Relax

Since I had a clutch issue recently (Thread), I decided to check the accumulated statistics from this poll thread - The results:

Spring Plate Failure Poll

>>> Rigid Mount Engine
Upto 50,000mi (84 Resp):
Good = 65 -- 77%
Bad == 19 -- 23%

Over 50,000mi (22 Resp):
Good = 19 -- 86%
Bad == 3 --- 14%

>>> Rubber Mount Engine
Upto 50,000mi (217 Resp):
Good = 106 -- 49%
Bad == 111 -- 51%

Over 50,000mi (22 Resp):
Good = 16 --- 73%
Bad == 6 ---- 27%


The over 50K numbers interest me most - If this problem was a wear issue, wouldn't the failure numbers (%) go up with more miles on the bike, especially after 50K miles?

The poll did not specifically inquire whether the Spring Plate was replaced without it failing - or whether the longer reported miles were after such replacement.

The results (which are, of course, anecdotal only) show most failures before 40K on rigid mounts or 30K for rubber mounts.

I wonder if this failure is related to something other than simply wear,
such as variations in:
mfr quality control?
assembling qc?
riding style?

Very interesting...

It is. After reading this I went out to the shop (garage) and found my spring plate. It's pristine having only a couple thousand miles on it. It's pretty simple. Two steel plates with leaf springs holding the plates slightly separated, held together by brass rivets. Mines' nominally .205" thick and .190" compressed so it "squishes" .015" Pretty complicated compared to the simplicity of the XR pieces.

But why do they fail? I dunno... only thing that comes to mind is that the steel (leaf) springs between the plates elongate (slightly) as the plates are compressed. Maybe this gnaws away at the rivets 'til they fail.

IF That was the case it's life would probably be measured in cycles, how many times the spring plate is compressed. Around town riding would put put failure far earlier than road riders putting on many miles without using the clutch.

Any other ideas? The one thing we KNOW is that they do fail and the results aren't pretty...

[IXL2Relax]

To me, the most certain fact is that the failure rate for Rubber Mount Engines (in this poll) is more than double the rate for Rigid Mount Engines. That has to be a significant factor in whatever the cause.

Although the engine vibrations on the rubber mount models were somewhat removed from the rider, those vibrations were not actually reduced. In fact, the rubber isolators simply allowed the vibrations to shake the engine, almost unrestrained.

To our knowledge, the MoCo made no alteration in the spring plate design or manufacturing at the time the rubber mount engine models were introduced that would account for why those models fail more. And, they did not alter the rubber engine mounts later to correct the problem nor stop using the spring plate design.

I doubt the cause of the spring plate failures can or will be definitively identified.

But what we do know makes one wonder, why?

IXL _______ >>>> My Motorcycle Chronicles Are Here <<<<

[Andy56]

I have seen pictures of the spring broken and some with rivets missing so there is two types of failure.

For the rivets I think as they have to be loose to allow the plates to move in and out there is a wear point.

I did wonder if peoples penchant to experiment with different oils might have anything to do with a brass rivet failure?

[Tomcatt]

Originally Posted by IXL2Relax

To me, the most certain fact is that the failure rate for Rubber Mount Engines (in this poll) is more than double the rate for Rigid Mount Engines. That has to be a significant factor in whatever the cause.

I'd take the poll results with a grain of salt. It's not a statistically valid sampling. Probably the most valid thing would be to lump the responses together and look at miles to failure.

[Bluto]

Originally Posted by IXL2Relax

To me, the most certain fact is that the failure rate for Rubber Mount Engines (in this poll) is more than double the rate for Rigid Mount Engines. That has to be a significant factor in whatever the cause.

Although the engine vibrations on the rubber mount models were somewhat removed from the rider, those vibrations were not actually reduced. In fact, the rubber isolators simply allowed the vibrations to shake the engine, almost unrestrained.

To our knowledge, the MoCo made no alteration in the spring plate design or manufacturing at the time the rubber mount engine models were introduced that would account for why those models fail more. And, they did not alter the rubber engine mounts later to correct the problem nor stop using the spring plate design.

I doubt the cause of the spring plate failures can or will be definitively identified.

But what we do know makes one wonder, why?

IXL _______ >>>> My Motorcycle Chronicles Are Here <<<<

Being that the rubber mount bikes are about 10% heavier and 10% more powerful that might have something to do with it