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Discussion Starter #1 (Edited)
So was at my favorite bike shop today getting parts for my wife's new 1981 Honda CM400. And decided to have them order a new chain/mud guard as my last one was eaten by my the rear tire in an odd set of circumstances last summer. One of the shop guys piped up and said that they might have one on a wrecked bike out back. We go have a look and sure enough there's half of a yellow ST3 with a perfectly fine carbon fiber hugger/chain guard. Asking about the accident, he explained that the bike BROKE IN HALF WHILE THE OWNER WAS RIDING IN MID CORNER. I'll see if I can get a picture of this tomorrow. But holy crap has anyone heard of a frame failure like this? The rider is apparently okay for the most part, banged up his knees pretty well. They're examining the bike and corresponding with Ducati. It was covered up in clear plastic outside but it looks like it broke just in front of the engine. Again, I'll see if I can take a picture tomorrow.
 

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Older members please help me out. I recall some kind of frame related problems with older ST models (ST2?) because of bolts that were too small. I don't recall frames splitting in half, however.
 

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Older members please help me out. I recall some kind of frame related problems with older ST models (ST2?) because of bolts that were too small. I don't recall frames splitting in half, however.
First time I have ever heard of a frame failure ever in 10+ years of ownership. I am aware of rear engine mount failures in a narrow batch, but never a frame breaking, has a cause been established? I hate bagging the brand without substantiation, it is simply not fair.

Craig
 

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New one on me. I've heard of the later bikes cracking the engine case at the rear mount. That one has been linked to engine mount bolts not to proper torque. Only other thing that comes to mind is the guy who had the bent shock link rod, but I think that ended up being an overloaded bike and a hard hit from a pothole in the road or the like.

Pic would be good. It's certainly not a chronic problem, or we'd know about it by now!
 
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It would be good to know where exactly the break happened. Were ST3's ever offered in yellow in the US?
 

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While prepping for a track day 4 or 5 years ago , I noticed a couple of hairline cracks in the rear left motor mount , ( barrel section that engine bolt passes thru/trellis tubes welded to), had it welded. A couple of years down the road it started to crack again. This time a sleeve was inserted and tig welded to original barrel, has been fine since. Just to be clear, it is a '98 ST2, that is well maintained.
 

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I was working at the dealership during the time the ST were produced and I have never heard of a frame breaking. Any product can be defective but it seems likely there was something else that set this in motion.

A customer brought in a monster once that he wanted to get going after it had sat for a few years, I examined it and found the front end broken/bent badly (19 degree head angle). He had run into the back of a car many years ago and though he did not crash the tube cracked and he did not notice. Over the next few years of normal use the crack got worse and the other tubes started to bend rearward, and he still did not notice.

There may have been a defect or the motor mounts may have been loose, this often breaks the engine case mounts when the motor and frame are floating together. I have not seen a frame break in this area but do know of a monster that broke in the similar area from jumping the bike with a loose engine. Hard to tell after the fact but I would bet the motor mount on the case failed or the motor mount had fallen out ( I have seen a 996 do this on the track) at which point the frame has no strength and would easily fail.

I cannot tell you how many times I see frame sliders installed incorrectly so that the motor is not held properly, the motor needs to be pinched tightly in the frame and if the slider is tight but the motor is not you could do this. Did the bike have sliders or were the motor mounts loose/damaged?
 

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Not trying to hijack thread here, on my ST2 , no frame sliders, and because of known engine bolt/case cracking issues, had engine bolts torqued to spec at every oil change(3,000 mi.) or major service.
 

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It was the engine mount bolts that I was thinking of. If I recall correctly, Ducati increased the diameter of the bolts in later models and/or someone introduced aftermarket ones.
 

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Ducati has increased motor mount diameter a couple times, Nichols MFG made some stronger bolts. I do not think either was because of the frame motors breaking as we did not have a issue back in the dark ages with the smaller bolts. I do not think we ever had a customer break a motor mount on one of our bikes we maintained and that included many race bikes that were crashed to pieces. We did see some brought to us to repair in fact a monster came up from NYC with broken cases that we warrantied for the customer and my monster is still using those warrantied/repaired cases 15 years later with no ill effect.

I think As power went up Ducati was trying to add more clamping force to the cases and increasing the bolt size allowed a higher torque. Most if not all ducati engine cases will be loose on the motor mount bolts so you can install them so even though you have a bigger stronger bolt if the bolt is not clamping tight then the engine will float on the bolt and it is this movement that breaks the cases.

One problem frame sliders can introduce is when a threaded shaft replaces the bolt and nut is that the installer needs to make sure the nuts are not bottoming in the threads, if the nuts bottoms before the frame clamps the engine tight the motor mount nuts will be tight but the motor will not be tight in the frame. I have found many sliders mounted like this and it is an installation error because the installer did not catch that the slider can be tight to the bolt but not clamping the motor tight.
 

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Discussion Starter #11
New one on me. I've heard of the later bikes cracking the engine case at the rear mount. That one has been linked to engine mount bolts not to proper torque. Only other thing that comes to mind is the guy who had the bent shock link rod, but I think that ended up being an overloaded bike and a hard hit from a pothole in the road or the like.

Pic would be good. It's certainly not a chronic problem, or we'd know about it by now!
I'm hoping to talk to the owner in the next few days and get the full story (and any past crash history). I was supposed to get by there today but work ran late. I'm stopping in Thursday and will take some pictures of the break and post them up.
 

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One problem frame sliders can introduce is when a threaded shaft replaces the bolt and nut is that the installer needs to make sure the nuts are not bottoming in the threads, if the nuts bottoms before the frame clamps the engine tight the motor mount nuts will be tight but the motor will not be tight in the frame. I have found many sliders mounted like this and it is an installation error because the installer did not catch that the slider can be tight to the bolt but not clamping the motor tight.
Thanks for the head's up. I've a slider like that on my 999s and I'll check it when I manage to chip it out of the icy garage with sprint thaw.

Ron
 

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Discussion Starter #13
http://imperialsportbikes.com/EzLis...0_EVO_V067307__Frame__id_278342_03_Damage.jpg

I could not get access to take a picture of the broken frame but found a comparable fracture online and am posting the link above. The cause was determined to be from corrosion that took place along the welds inside the frame. There was no external indication of fatigue or distress on the welds where the chassis joins the head tube of corrosion. Which is concerning, as there's now way to know if there is an issue. The mechanics suspicion is that during production the frame was not properly treated for anti corrosion.
 

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Granted we cannot see the frame or the damage so the mechanic looking at it might be the best judge. I would be shocked if there was a ducati frame that has ever had a failure due to rust. I am in New England and we know rust quite well and I see bikes that ride year round in salt, I have never seen a rust damaged motorcycle frame. The one in the photo attached broke at the steering head and is more common when the bike has a direct impact and stresses the tubes, you can see the top tubing has torn and the welds are intact. Likely the forks worked as lever and were pushed in tearing the upper tubes.

Rust can and does effect the frames but given we see bikes left buried under feet of snow and ridden in a salt bath if the frames were prone to rust failures I would think it would be all over the internet. More likely the frame broke and then water entered the frame and rusted the area around the break and is making it look worse than it was.

C-simian
If the slider mounts can be easily turned and do not tighten then you need to add spacers to keep the slider nuts from bottoming, these can be any steel or aluminum spacer combination you can come up with that lets the motor mount take torque and fit the slider pucks.
 

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Discussion Starter #15
Granted we cannot see the frame or the damage so the mechanic looking at it might be the best judge. I would be shocked if there was a ducati frame that has ever had a failure due to rust. I am in New England and we know rust quite well and I see bikes that ride year round in salt, I have never seen a rust damaged motorcycle frame. The one in the photo attached broke at the steering head and is more common when the bike has a direct impact and stresses the tubes, you can see the top tubing has torn and the welds are intact. Likely the forks worked as lever and were pushed in tearing the upper tubes.

Rust can and does effect the frames but given we see bikes left buried under feet of snow and ridden in a salt bath if the frames were prone to rust failures I would think it would be all over the internet. More likely the frame broke and then water entered the frame and rusted the area around the break and is making it look worse than it was.

C-simian
If the slider mounts can be easily turned and do not tighten then you need to add spacers to keep the slider nuts from bottoming, these can be any steel or aluminum spacer combination you can come up with that lets the motor mount take torque and fit the slider pucks.
With all the high milage ST's out on the road if this was a wider ranging issue I'm sure we'd know about it right? Perhaps it's just a random quality control oversight. The interesting thing about this is, there's zero signs of rust anywhere on the bike, except inside the frame. Water condensation must have gotten in somehow. Rider said he felt something unsettle and pull him off his line in the previous corner (probably the lower section of the chassis separating from the head tube), then the top section started to go in the next corner, changing the rake of the bike and it refused to turn in or hold a line at all. He said went into the guard rail at about 20-25.
 

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Older members please help me out. I recall some kind of frame related problems with older ST models (ST2?) because of bolts that were too small. I don't recall frames splitting in half, however.
you're right, Bill. As other have mentioned, the early bikes, like 1997 thru 1999 maybe?, they had the smaller dia. engine bolts. And there were a few that had snapped. IIRC, the nut or bolt head was still there via the frame "plugs" that covered over the recessed area. The early bikes had these cosmetic plugs.

I could just see the mechanic's eyes when he pulled the frame plug to check the torque, and the big piece fell into his hands!
 
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