Any ideas on how this cracked sprocket could happen?
Discussion
Cleaning the chain last night on the 899 and noticed a bush missing from my chain. New one on me.
Rotated the chain some and then noticed a broken tooth on the rear sprocket. Not THAT unusual.
I went to remove the old sprockets and chain and noticed this crack on the rear sprocket. Another new one on me.
So any ideas as to what is the likely cause of this? Chain and sprockets are AFAM so not particuarly cheap cr@p. Would like to try and avoid this in the future obviously...
Rotated the chain some and then noticed a broken tooth on the rear sprocket. Not THAT unusual.
I went to remove the old sprockets and chain and noticed this crack on the rear sprocket. Another new one on me.
So any ideas as to what is the likely cause of this? Chain and sprockets are AFAM so not particuarly cheap cr@p. Would like to try and avoid this in the future obviously...
No, not owned from new. Found out last Monday it was an ex California Superbike School bike (registered as Ducati UK Silverstone the sneaky s
ts) then owned by some guy in Falkirk for a year (not MTB). 2014 model, under 15k miles when I bought it, FSH last 2 services including valves done by Ducati Glasgow. So pretty solid on the service front IMO.
ts) then owned by some guy in Falkirk for a year (not MTB). 2014 model, under 15k miles when I bought it, FSH last 2 services including valves done by Ducati Glasgow. So pretty solid on the service front IMO.freddytin said:
I've seen similar damage ......The initial problem being a missing roller on the chain, like yours.
The subsequent damage to the sprockets being caused by incorrect alignment of chain into cutouts,
Has to be this surely?The subsequent damage to the sprockets being caused by incorrect alignment of chain into cutouts,
Missing roller on chain, poor alignment, repeated smashing the s
t out of your rear sprocket (you can see the gouging of material), and eventually the sprocket gives way.Replace both sprockets and chain, then go in peace?
Prof Prolapse said:
freddytin said:
I've seen similar damage ......The initial problem being a missing roller on the chain, like yours.
The subsequent damage to the sprockets being caused by incorrect alignment of chain into cutouts,
Has to be this surely?The subsequent damage to the sprockets being caused by incorrect alignment of chain into cutouts,
Missing roller on chain, poor alignment, repeated smashing the s
t out of your rear sprocket (you can see the gouging of material), and eventually the sprocket gives way.Replace both sprockets and chain, then go in peace?
If it was done via the roller coming off the chain then it probably did it straight away or as has been said, it's picked something up and caused massive leverage to split the sprocket and rip the roller off.
curlie467 said:
Prof Prolapse said:
freddytin said:
I've seen similar damage ......The initial problem being a missing roller on the chain, like yours.
The subsequent damage to the sprockets being caused by incorrect alignment of chain into cutouts,
Has to be this surely?The subsequent damage to the sprockets being caused by incorrect alignment of chain into cutouts,
Missing roller on chain, poor alignment, repeated smashing the s
t out of your rear sprocket (you can see the gouging of material), and eventually the sprocket gives way.Replace both sprockets and chain, then go in peace?
If it was done via the roller coming off the chain then it probably did it straight away or as has been said, it's picked something up and caused massive leverage to split the sprocket and rip the roller off.
curlie467 said:
A chain doesn't hit the same tooth every revolution though.
If it was done via the roller coming off the chain then it probably did it straight away or as has been said, it's picked something up and caused massive leverage to split the sprocket and rip the roller off.
Yeah of course. Makes sense. If it was done via the roller coming off the chain then it probably did it straight away or as has been said, it's picked something up and caused massive leverage to split the sprocket and rip the roller off.
Just throwing ideas out, but what about something like the output shaft bearing?
If it was on it's way out, it would presumably alter the rotation on the front sprocket the misalign the chain? Whipping it up at the rear and taking chunks out of ther rear sprocket (and even damage a roller, which could be a symptom rather than cause, as I jointly speculated earlier).
Presumably simple enough to check the rotation is true, when you are changing the chain and sprockets.
Just a thought.
If it was on it's way out, it would presumably alter the rotation on the front sprocket the misalign the chain? Whipping it up at the rear and taking chunks out of ther rear sprocket (and even damage a roller, which could be a symptom rather than cause, as I jointly speculated earlier).
Presumably simple enough to check the rotation is true, when you are changing the chain and sprockets.
Just a thought.
naetype said:
No, not owned from new. Found out last Monday it was an ex California Superbike School bike (registered as Ducati UK Silverstone the sneaky sts) then owned by some guy in Falkirk for a year (not MTB). 2014 model, under 15k miles when I bought it, FSH last 2 services including valves done by Ducati Glasgow. So pretty solid on the service front IMO.
To be fair, my 899 was ex-CSS and was immaculate. I ran it for nearly 3 years and sold it with similar mileage to yours (2015 bike). I would buy from them again although people seem to think they're shagged. A 6 month old 899 for 9k didn't really lose me any money over the 3 years. ts) then owned by some guy in Falkirk for a year (not MTB). 2014 model, under 15k miles when I bought it, FSH last 2 services including valves done by Ducati Glasgow. So pretty solid on the service front IMO.surely that's a solid object getting stuck between the chain and sprocket and the sprocket tooth giving way first and snapping off
you're lucky it was the tooth and not the chain
that aside - are the sprockets on the right way? The rear for sure can have a 'wayness' - wrong way and it'll be to far left or right (they're not all like this) - just looking at the way the teeth have worn oddly on the side
you're lucky it was the tooth and not the chain
that aside - are the sprockets on the right way? The rear for sure can have a 'wayness' - wrong way and it'll be to far left or right (they're not all like this) - just looking at the way the teeth have worn oddly on the side
What is it with 899’s and chain/sprocket threads?!
https://www.pistonheads.com/gassing/topic.asp?h=0&...
https://www.pistonheads.com/gassing/topic.asp?h=0&...
MrGman said:
Stone or something getting caught just at the wrong time?
This, absolutely this.Absolutely this and nothing else such as misaligned wheels, output shafts, poor lubrication or even Donald Trump.
A piece of gravel gets pinged up by the tyre and sticks between the chain and sprocket; either the chain snaps or the sprocket does, depending on where they all come together.
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