Serious Safety Issue on a 2009 Monster 696

[mikesmithmjs]

Hi All,

I wanted to inform the Monster community of a serious safety issue that occurred on my 2009 Ducati Monster 696.  

My Monster has approximately 3100 thoroughly enjoyed miles. (The bike is a few months out of warranty.)  However, last week I encountered a serious mechanical malfunction and was lucky to walk away unharmed.  The original front drive sprocket slipped on the transmission rod towards the center of the bike forcing the chain to act as saw.  This ate into a significant portion of the rear swing arm.  The local dealer estimates ~$3000 in repairs including labor. (Replacement drive rod, chain, swing arm, and possibly the sprocket.)

Apparently, the same mechanism to hold the front sprocket on has been used on many Monsters.  I argue that this type of mechanical malfunction should never happen. One time should be a warning that a better engineered mechanism that prevents the meandering of the front sprocket should be in place. Since it happened to me and I was fortunate enough not to end up in a crash, i feel that I have to inform anyone who loves riding their Monster.  

Has anyone else encountered this issue?

Thanks,

Mike

PS I'd post photos if I can figure how to post them.















 

[Grampa]

hmmmmmmmm

[somegirl]

Photo posting FAQ: http://www.ducatimonsterforum.org/index.php?topic=109.0

[mitt]

Something fishy here.  The chain is not a saw - it would take many miles of wear to create a sawing affect IMO.

I also do not see how it could get closer to the center of the bike - can you explain better?  What is the mechanism that failed?

mitt

[derby]

PS I'd post photos if I can figure how to post them.

please do, because what think you're saying doesn't exactly make sense to me.

are you saying the splines failed on the drive shaft? or did the bolt holding the front sprocket come loose and allow the sprocket to work itself off the shaft?

[MadDuck]

I agree that something sounds odd here.  Not that it should matter that much but was a 14 tooth countersprocket installed?

[orangelion03]

Dont know about 696, but on my S2R 800, the engine sprocket is held in place by an oblong plate the locks into the splines and attaches to the sprocket with two small bolts (8mm?).  If those screws come loose, the sprocket can slip in/out on the splines.  I am assuming that this being a new bike, you havent had to touch the sprocket, so perhaps the screws were improperly tightened at the factory.  I just replaced my sprockets for the second time (22K miles) and used blue Loctite and torqued the screws to the manual specified value.

[mikesmithmjs]

Hi Guys,

The sprocket was the original 15 tooth and was never touched.

The Sprocket slid on the splines toward the center of the bike and the chain sawed just like a chain saw into the rear swing arm. However the mechanic said the bolts on the plate were tight.

I'm going to set up a photo account to post the pics i have on this computer.

Mike

[mikesmithmjs]

I will post more photos later of the drive shaft splines and sprocket and all the surrounding metal shards as a result of the cutting into the swing arm.

I can only imagine what could have happened if the chain broke or cut even more into the swing arm or the sprocket slid away from the bike.

[battlecry]

If the two bolts were tight, then the locking splines are gone.  If the splines are good and the bolts are tight, then the plate holes for the bolts are loose enough to allow the splines to clock and unlock.  The locking splines on the plate will wear, but it shouldn't happen at your miles, Mike.

When you get it fixed, ask them to safetywire the two little bolts.  I actually prefer the plate/spline/bolts sprocket holding mechanism over a tight bolt on the splined shaft.

[mitt]

this is about as robust a system as you can have.  There is some special cause to your problem (sprocket installation backward or wrong part)

[mikesmithmjs]

Hi Mitt,

Thanks for the diagram.

Apparently i have proof that it isn't robust. I believe that robustness is when something is not quite right, say a bolt not torqued perfectly the whole system should still stay intact. I now have 3k in damage and no real explanation as to why it happened.

Does anyone think Ducati will repair this for me on their dime?

Mike

     

[Raux]

too bad you didnt take photos before the mechanic touched it.

also, can you take photos of each part

if the bolts were tight and the splines on the ring are intact and the gear was on the correct way...
have you ever had your tires changed? same mechanic?

[mikesmithmjs]

Raux,

All photos are from before mechanic touched it.

It was in the shop the week before for an oxygen sensor replacement.

[matt922]

you better jump on this little present i found for you...

http://cgi.ebay.com/ebaymotors/2009-09-Ducati-monster-M696-swingarm-swing-arm-98621-_W0QQcmdZViewItemQQhashZitem4cec5d324aQQitemZ330383045194QQptZMotorcyclesQ5fPartsQ5fAccessories