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Discussion Starter · #1 · (Edited)
Hey guys,

Bad day here. Anybody ever seen a 2013 multistrada 1200 fail like this? Bought the bike new and have just over 11k miles.

Went to go for a ride the other day and it wouldn’t start. Figured sprag clutch after some research but apparently this is much worse. The crankshaft seems to have fractured.







The sprag clutch assy seems to function ok though...

Time for a 1198 motor with 1098 cams?
 

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Hey guys,



Bad day here. Anybody ever seen a 2013 multistrada 1200 fail like this? Bought the bike new and have just over 11k miles.



Went to go for a ride the other day and it wouldn’t start. Figured sprag clutch after some research but apparently this is much worse. The crankshaft seems to have fractured.



https://imgur.com/gallery/XX8A7Gn



https://imgur.com/gallery/XX8A7Gn



The sprag clutch assy seems to function ok though...



Time for a 1198 motor with 1098 cams?


I have had 1 instance of MTS1200 crankshaft failure in the past 8years, but not in that location. If you’re the original owner, and have a full service history on the machine, request that your dealer submit a goodwill request to Ducati. It’s a long shot, but worst case scenario is a ‘no’.


Sent from my iPhone using Tapatalk
 

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Discussion Starter · #4 ·
I have had 1 instance of MTS1200 crankshaft failure in the past 8years, but not in that location. If you’re the original owner, and have a full service history on the machine, request that your dealer submit a goodwill request to Ducati. It’s a long shot, but worst case scenario is a ‘no’.


Sent from my iPhone using Tapatalk
Yeah luckily I did but it new, have had it serviced per ducati recommendations at the dealer, and have a good relationship with the dealer. Hopefully they’re willing to work with duc on it. If they do say no I will bring it to work to determine fracture mode and check the material and will submit a report to ducati on it. Maybe the crank was defective...
 

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Gawd. That's awful. Keep us posted, but yeah, if you've got service records, I'd throw myself on the mercy of Ducati USA.
 

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Discussion Starter · #6 ·
from my key board looks like an crankshaft bearing failure
Curious why you say that?

Do you feel that the crank bearings could have been failing and when the engine shut down it locked so abruptly that the flywheels momentum caused it to break the shaft?

Or the other scenario where the starter attempted to spin the motor and couldn't, due to main bearing failure, so it broke the shaft? I'd be surprised if the starter could break the crank before stalling or damaging the gears/sprag. I found no evidence of damage to any of the starter components.

There were no apparent running issues, prior to it not starting either.

Maybe i should pull the clutch cover...

I did bring the flywheel to one of my materials failure analysis buddies. I am hoping that he can shed some light on a likely failure mode of the shaft which we can then attribute to a system level failure.

Cheers,
Chris
 

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So, you're a metallurgist, or have access to that sort of analysis? That's excellent, and potentially good for your cause, and for Ducati to suss out the underlying failure.
 

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I have seen crankshafts break in the past (not specifically the 1200) but it is pretty rare, my gut feeling is that the crank was defective. plenty of main crank bearing failures without this happening as well as alternator bearing failures and then the usual rod bearings or engine blow ups and still not what you are seeing here.

If the starter clutch was to lock things up solid and/or the gear between the starter motor and starter gear seized then the crank turning under power mixed with a starter clutch that was essentially locked up tight might be able to twist the crank. Easy to see if the starter intermediate gear as well as the starter clutch is functioning. I will add The above scenario has happened without breaking cranks in the past.
 

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Oddly, the Aprilia dealer in Houston (Italian Superbikes) mentioned to me last year that he'd heard about this issue. Apparently a defect that can be traced back to the 1198 part.
 

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Discussion Starter · #11 ·
Interesting on the defect.

Wmfleet, not sure what you mean. There isn’t much smearing so it wasn’t sitting there rubbing on itself but looking at it under the microscope it looks to me like there are a bunch of little fatigue cracks propagating from the inner radius of almost every spline. In my untrained opinion, they all just finally grew together and let go.

Redbrit, I am not a metallurgist but we do have a metallurgical group where I work.

If ducati isn’t helpful the guys at work are willing to determine the failure mode.
 

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Yes looks like a classic torsional fatigue failure. Was there any balance issue with the flywheel?
If not maybe a manufacturing defect.
 

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Did a lot of reliability testing during my working career. At one place I worked, I designed hip implants and tested them on an Instron testing machine. We would apply a load of about 500 lb, cyclically, at a frequency of 10 Cycles/ sec to the top end of the implant that was cemented into a fixture. These implants were all made from the same forging and then machined to the exact same specification on the same machine. We tested them until they broke due to fatigue. The number of cycles it took to break the implants varied considerably. The results followed your typical bell curve. With the mean around around 13,000,000 cycles. But we did have one that broke at below 10,000,000 cycles and a few that never broke (went up to 20,000,000 cycles. The molecular structure of a metal part consists of many slip planes. The molecules are not all congruent and perfectly aligned. These discrepancies cause the working life to vary considerably. Engineers design parts to have a typical life for a particular application. The mean time before failure is usually a well acceptable time frame. Even the best designs still have alot of variability. You will always have parts that last forever and parts that break early on. It is usually not a problem, unless you start to see alot of failures that fall outside the typical bell curve.

The failure seen here is not a common one. Hard to say from the info if its a defect of the metal or something else was going on. An investigation into it should easily illuminate the exact cause. It sucks when its your bike. I bought my first Ducati, a used monster with 4,000 miles, years ago. 1 week after I bought it, I changed the oil and found the left main bearing retainer in pieces in oil the pan! Not good.
 

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Discussion Starter · #14 ·
Yes looks like a classic torsional fatigue failure. Was there any balance issue with the flywheel?
If not maybe a manufacturing defect.
I definitely agree. Showed it to a metallurgist friend that I trust and he said the same, "textbook torsional fatigue" as he put it.

Not sure on balance issues. I plan on checking static balance but don't want to disassemble anything any further until we hear back from Duc, in order to preserve any evidence.

ducatimike, yeah i definitely hear that. I'm in a component failure analysis group at an aerospace company so I'm relatively well versed in qual/acceptance testing and MTBF side of things. I guess what we do at work is more of a life or death thing, while a motorcycle crankshaft failure is basically an inconvenience. I'd just hope that the curve was shifted far enough to the right for these things to not pop up at such low mileage, barring any material/manufacturing issues. From what i can tell, it seems like the Jap mfgs have it figured out...


On a side note, anyone know compatibility of other 1198 series engines (1198 or Monster 1200) to the MTS chassis? Pending more research, i am leaning towards the sbk engine if i do have to replace...
 

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I'm wondering about balance issue due to location of failure. In many car/truck engines they use a harmonic balancer to deal with resonant vibration due to the acceleration/ deceleration of the crank through each revolution.
Looking at the splines , is it possible that it is supposed to be aligned for balance?
 

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Discussion Starter · #16 ·
I'm wondering about balance issue due to location of failure. In many car/truck engines they use a harmonic balancer to deal with resonant vibration due to the acceleration/ deceleration of the crank through each revolution.
Looking at the splines , is it possible that it is supposed to be aligned for balance?
Yeah kind of surprising that bikes don't use a harmonic balancer...

As for balance, i don't see any balancing marks on the flywheel itself. Also not sure if the flywheel is "keyed". There is a short spline (about half the height of the others) on the crank but not sure if this interfaces with anything on the FW. As mentioned I plan on setting up a jig to check static balance when/if Duc tells me to pound sand.
 

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Discussion Starter · #17 ·
Removed the flywheel. Interesting how the cracks run right down the splines and then propagate as fatigue cracks at the ~45degree angles.

No word from DNA yet.



 

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Doesn’t look like “classic” torsional fatigue. No plain lines, which is classical of torsional fatigue. Looks like harmonics at the end of the crank over time caused micro fractures. I witnessed a few early Gsxr cranks fail caused by replacing the rubber engine mounts with solid aluminium. Rubber dampened engine would typically last two seasons whereas solid mounted ones would break cranks within 6 months.
 

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That looks a bit like the flywheel was loose and has been rattling back and forth to cause wear on the splines like that.
 

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Discussion Starter · #20 ·
Doesn’t look like “classic” torsional fatigue. No plain lines, which is classical of torsional fatigue. Looks like harmonics at the end of the crank over time caused micro fractures. I witnessed a few early Gsxr cranks fail caused by replacing the rubber engine mounts with solid aluminium. Rubber dampened engine would typically last two seasons whereas solid mounted ones would break cranks within 6 months.
There are the classic plane lines, they just run along the splines in that super sharp “radius”

Super interesting about the crank life with solid mounts! Never would have thought about that...
 
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