Clutch fiction disk blew up, again.

Joined
Dec 18, 2025
Messages
11
Age
29
Location
Colorado
Bike
St1300
Hello. 6 month ago some of my 2003 st1300 clutch friction disks shattered into many pieces while ridding. I made post about it here. https://www.st-owners.com/forums/threads/clutch-friction-disk-disintegrated-why.190847/ Now 6 months later it has happened again. I took it apart and the friction disk had the same problem. It completely fused to the steel plate, I assume from heat. One thing I noticed is that the friction disks seem dry, one seems incredibly dry. I have uploaded a picture of that particular disk. It feels dry to the touch and I think it even looks dry in the picture. These are supposed to be constantly bathed in oil right? It seems like the clutch area is not directly connected to the oil drain pain because in the drain pan that section is partitioned away from the main area. Is there something that squirts oil into the clutch area, or some sort of lubrication system I should try and diagnose. Thank you, any info would be super helpful.

This first pic shows the broken friction disk along with a very dry friction disk.
The second pic is just the clutch area, if its at all helpful.
 

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Are you doing a lot of low speed maneuvers, like the cops like to do.

It looks similar to the clutch I removed from the ex cop bike I took the engine out of to put in the AZ05 ST1300, although there were no broken clutch parts.

20250403_CopClutch-burnt.jpg
 
Are you doing a lot of low speed maneuvers, like the cops like to do.

It looks similar to the clutch I removed from the ex cop bike I took the engine out of to put in the AZ05 ST1300, although there were no broken clutch parts.

20250403_CopClutch-burnt.jpg
Yeah, well. I was again doing low speed u turns. I'm willing to concede that I just have poor technique if you convince me. I try to make them fairly tight and rev the engine to around 4k rmp using the clutch to control speed. I'll admit I drag that rear brake a little, perhaps too much? I only did around 20 u turns before the thing blew up. I can only imagine that the police officers when training abuse the clutch far more then that and these things are expected to handle it right? Perhaps I'm just destroying my clutch, but that friction plate is really dry and it seems to me regardless of the u turns that should not be that case.

Were the replacement fiber disks soaked in oil overnight before assembly?
Definitely, that was 6 months ago.

Oh btw, on the last post I was not sure if my oil level was good. Now I am, after this incident I checked the oil level and it was just a bit bellow the high mark.
 
About the time of my accident in 2008, I was talking to a shop that was servicing the local cop ST1300s and the guy told me that their clutches were not lasting very long at all. And then when you add the training with the low speed maneuvers, it just adds to their quick demise.

When I was commuting, I found, due to the constant off and on the clutch I was doing, Lane Splitting, my clutches were only lasting me around 60K miles, before I had to replace them.

As for yours breaking apart like that, low oil could be a factor. But at the same time, if you are doing a lot of the low speed drills, do expect your clutches, not to last too long.
 
About the time of my accident in 2008, I was talking to a shop that was servicing the local cop ST1300s and the guy told me that their clutches were not lasting very long at all. And then when you add the training with the low speed maneuvers, it just adds to their quick demise.

When I was commuting, I found, due to the constant off and on the clutch I was doing, Lane Splitting, my clutches were only lasting me around 60K miles, before I had to replace them.

As for yours breaking apart like that, low oil could be a factor. But at the same time, if you are doing a lot of the low speed drills, do expect your clutches, not to last too long.
Thanks for that info. There is a difference, I think, between a clutch losing it's friction material too quickly and fusing too the clutch plate before shattering, within 6 months of doing the same thing. I now feel pretty convinced that there is a problem with my clutch lubrication system. Does anyone know if the clutch sits in a bath of oil or if there if something is supposed to supply the clutch with oil directly? I see at the bottom of the drain pan, on the clutch section, there is filter presumably to suck oil back in? Is there something that adds oil into the clutch area?
 
Thanks for that info. There is a difference, I think, between a clutch losing it's friction material too quickly and fusing too the clutch plate before shattering, within 6 months of doing the same thing. I now feel pretty convinced that there is a problem with my clutch lubrication system. Does anyone know if the clutch sits in a bath of oil or if there if something is supposed to supply the clutch with oil directly? I see at the bottom of the drain pan, on the clutch section, there is filter presumably to suck oil back in? Is there something that adds oil into the clutch area?

Yeah, that would be a question for @aniwack ?
 
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