Aluminum flywheel failure

[footgoose]

There are at least 2 cases of flywheel failure documented on this forum. I don't have them archived or I'd link them. They can be found if you dig deep enough. Proof enough to make me swap my clutch and flywheel, as many others have done. If yours didn't fracture, you had good fortune. I hope it lasts. Mine didn't fail in 11,500 mi. from new, nor was it cracked when I removed it. Not everyone's shift selector spring broke either, but my personal preference was to swap it out and not be constantly wondering how much time is left before I'm stranded, or worse.

All (or most) 2002 engine cases had the paint problem. The factory offered a fix but I didn't bother. When I swapped the clutch, I stripped and painted the motor.

[Paradiso]

Do you know anyone yourself or have you seen one in personn? a single plate clutch "Blown up"? There was one photo of one several years ago that failed..although I have never read a personal account about it..The phot has been beaten to death over and over for 10 years or more on the internet but I have yet to see one that "blew up" or to meet anyone on any of the forums who had one "blow up" them selves..I've owned 3 2002 V-11's
2-Scura's and a  Rosso Mandello. with them..none blew up...So yes..I'd like to see some "Solid" information too.

My Tenni, which I still have, had cracks around the bolted centre (of the flywheel) when I replaced it with a dual plate clutch. I posted photos when I did the job. It would have broken apart if I hadn't replaced it. The bike had done about 13 000 miles at this point.

Sent from my SM-S901B using Tapatalk

[Paradiso]

My current phone is not very good for close up photos, but you can see the cracks.


Sent from my SM-S901B using Tapatalk

[Rox Lemans]

The "Explodamatic Single Plate" thing shouldn't be a worry until around 25-30k miles.  My Scura was an exception at 23k since the guy who had it used it on the track. But it's not that it's a bad flywheel. It's a really good flywheel. But it's a RACING lightweight flywheel and not designed for performance, not longevity. There are guys here with the dual plates with 100k+.  

But with any of these performance flywheels, it's something to be aware of. Changing that flywheel is no picnic. In fact, it sucks. But the photo above is how it starts. I'm prety sure the flywheel that was pulled out of my Scura started cracking in the same spot. But the bike will give plenty warning. You can hear it and feel it. And apparently, you can't just swap for a dual plate. At least that's what I was told. 

[KINDOY2]

16 hours ago, footgoose said:

There are at least 2 cases of flywheel failure documented on this forum. I don't have them archived or I'd link them. They can be found if you dig deep enough. Proof enough to make me swap my clutch and flywheel, as many others have done. If yours didn't fracture, you had good fortune. I hope it lasts. Mine didn't fail in 11,500 mi. from new, nor was it cracked when I removed it. Not everyone's shift selector spring broke either, but my personal preference was to swap it out and not be constantly wondering how much time is left before I'm stranded, or worse.

All (or most) 2002 engine cases had the paint problem. The factory offered a fix but I didn't bother. When I swapped the clutch, I stripped and painted the motor.

I do not have a 2002 bike with a single clutch assy anymore...of the 3 2002 I had, 2 Scuras and one Mandello..one had 25,000 mi on it  when i sold it 4 years ago and now has over 35,000 miles on it is still working fine for the current owner.., The other 2002  had 18,000 miles on it when I rebuilt the entire bike including complete tear down of the motor to powdercoat the cases, it did not have any cracks but I put a different clutch in it anyway since it was all apart, the third had less than 10,000 which I bought crashed and I still have the motor here with original flywheel..it is not cracked.

Approximately what year's was it when these 2 previous incidents were posted? I have looked extensively ..both here and in Italy over the past few years and did not run across these.

Thanks

 

[Paradiso]

The "Explodamatic Single Plate" thing shouldn't be a worry until around 25-30k miles.  My Scura was an exception at 23k since the guy who had it used it on the track. But it's not that it's a bad flywheel. It's a really good flywheel. But it's a RACING lightweight flywheel and not designed for performance, not longevity. There are guys here with the dual plates with 100k+.  
But with any of these performance flywheels, it's something to be aware of. Changing that flywheel is no picnic. In fact, it sucks. But the photo above is how it starts. I'm prety sure the flywheel that was pulled out of my Scura started cracking in the same spot. But the bike will give plenty warning. You can hear it and feel it. And apparently, you can't just swap for a dual plate. At least that's what I was told. 

I don't think the flywheel failure would be a gradual or predictable thing. How could you tell when the cracks shown in my photo would spread and the flywheel break apart? People are free to make their own guesses, but I would not take the risk.
I took mine apart because the clutch was worn. I only noticed the cracks afterwards. The twin plate V11 sport clutch is a direct replacement. The new parts about 8 years ago were over £2500. I managed to find a second hand steel clutch assembly for a lot less, but it took some time.

Sent from my SM-S901B using Tapatalk

[Rox Lemans]

37 minutes ago, Paradiso said:

I don't think the flywheel failure would be a gradual or predictable thing. How could you tell when the cracks shown in my photo would spread and the flywheel break apart? People are free to make their own guesses, but I would not take the risk.
I took mine apart because the clutch was worn. I only noticed the cracks afterwards. The twin plate V11 sport clutch is a direct replacement. The new parts about 8 years ago were over £2500. I managed to find a second hand steel clutch assembly for a lot less, but it took some time.

Sent from my SM-S901B using Tapatal

It's not that I can tell WHEN. It's just WHEN they tend to crack. That's where mine started. Anyone whose had to change their flywheel had to around 25k miles/40k km. Consider it anecdotal. But it's been consistent. And that grinding sound when you rev the motor in neutral at high rpm? Anecdotal? 

You catching yours when you changed the clutch without the symptoms may be you got lucky. I've never seen one explode, but I've seen the pics of shards of crankcase.. Not good at all.  

But as I've said, these performance flywheels were put in for performance, not longevity. Likely, something nice to put in the moto magazines: "Look! A racing flywheel!!"  It's why my Scura has become my special occasion bike. Keep it clean and look pretty cruising. 

[p6x]

38 minutes ago, Paradiso said:

People are free to make their own guesses, but I would not take the risk.

Completely concur!

My strategy is always to right whatever I find wrong, as soon as I detect it. It may not be cheap, but it could save you from a larger expenditure later.

My 911 Porsche was making that rickety noise when starting cold. The distribution chain tensioner is hydraulic. However, on cold start, when there is no pressure, the tensioner relies on a spring until the oil pressure comes up. It is a few seconds. I did not like that brief rattling noise, which did not exist before. I got both left and right bank tensioner springs replaced, even if you have to take the engine down to change a ten dollars spring.

[footgoose]

there are enough to make me swap it out.

 

another

unfortunate the pics are gone from this post. I believe this one was the one that blew out the bell housing part of the engine case. If you saw this photo you would be convinced. It may have been reproduced in another thread. Search more, it goes waaay back. Exploding clutch, exploding flywheel, etc

another

[footgoose]

more with pics

 

 

 

[docc]

There have long been concerns, and reports, of cracking or failures of the aluminum flywheel mated to the single plate clutch on the 2002 Scura, 2002 Tenni, and (perhaps) the 2001 Rosso Mandello.

To clarify: it is not a clutch failure, but cracking of the flywheel around its mounting to the crankshaft potentially progressing to separation and extensive damage. Many have preemptively converted their "single plate clutch"/ aluminum flywheel to the V11 double plate/steel flywheel or installed an aftermarket RAM clutch/flywheel unit. Those solutions are detailed elsewhere and may be linked here.

This topic is meant to chronicle reports of actual failures.

 

[GuzziMoto]

Not totally on topic, but has anyone here seen this story about a saw blade that made a run for it?

https://www.nbcnews.com/news/man-narrowly-escapes-saw-blade-barreling-oregon-rcna145784

[docc]

Seems like that sort of thing deserves a topic of its own off in Banter . . .

[GuzziMoto]

7 minutes ago, docc said:

Seems like that sort of thing deserves a topic of its own off in Banter . . .

Perhaps, but it also highlights the danger of a disc spinning as fast as the flywheel is spinning. It isn't just a question of how much damage it can do to your Guzzi if your aluminum flywheel lets go, it can do damage to you. There is a reason why drag racers have to use SFI rated bell housings.

Anyway, feel free to delete the post.

[docc]

5 hours ago, GuzziMoto said:

Perhaps, but it also highlights the danger of a disc spinning as fast as the flywheel is spinning. It isn't just a question of how much damage it can do to your Guzzi if your aluminum flywheel lets go, it can do damage to you. There is a reason why drag racers have to use SFI rated bell housings.

Anyway, feel free to delete the post.

No way would I delete your posts.

Reminds me of why Don Garlits built the rear engine dragster.

edit:

https://www.forbes.com/sites/jimclash/2023/03/16/how-big-daddys-1970-wreck-revolutionized-dragster-design-saving-countless-lives/?sh=168d33e25cc9