Excessive wear on rear sprocket

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Elvis
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Excessive wear on rear sprocket

Post by Elvis » Fri Aug 31, 2018 6:03 pm

Hi Guys,
I had a complete set of chain and sprockets installed by the dealer, 5000km after the rear sprocket shows excessive wear, the front looks like new.
The set is from JT and i am using them since ever with no issues on other bikes.
Any idea why the excessive wear? can it be due to too loss or too tight chain? normaly i do by the book but last year my bike broke down in Italy and the KTM dealer there tighten it a bit more and i rode 1000km back home like this, can this be the reason?
Sprocket 1.jpg

Elvis
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Re: Excessive wear on rear sprocket

Post by Elvis » Fri Aug 31, 2018 6:05 pm

Sprocket 2.jpg

Magic Wand
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Re: Excessive wear on rear sprocket

Post by Magic Wand » Fri Aug 31, 2018 9:37 pm

Hi 'Elvis'
Maybe a stupid question, but is that aluminum rear sprocket?
The excessive wear appears to be at the top of the teeths - correct? That's odd, I havn't seen anything like that. Not even at motocross bikes.
Sorry, I have no explanation.

/M

Zombie Master
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Re: Excessive wear on rear sprocket

Post by Zombie Master » Sat Sep 01, 2018 5:23 am

If the chain was adjusted too tight, that could cause that problem. As MW asked, if they installed an aluminum sprocket, then that could explain why it has worn out so fast. The combination of an aluminum sprocket and over tightening would explain the short life.

Elvis
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Re: Excessive wear on rear sprocket

Post by Elvis » Sat Sep 01, 2018 10:53 am

Its a C49 steel like on the original ESJOT.
I replaced it now with JT Steel 42T hoping bigger diameter will help here.

Zombie Master
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Re: Excessive wear on rear sprocket

Post by Zombie Master » Sun Sep 02, 2018 6:43 am

Have you examined your counter shaft sprocket?

Elvis
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Re: Excessive wear on rear sprocket

Post by Elvis » Sun Sep 02, 2018 9:57 am

Zombie Master wrote:
Sun Sep 02, 2018 6:43 am
Have you examined your counter shaft sprocket?
Yes and it looks like new.

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Re: Excessive wear on rear sprocket

Post by Zombie Master » Tue Sep 04, 2018 6:20 am

Elvis wrote:
Sun Sep 02, 2018 9:57 am
Zombie Master wrote:
Sun Sep 02, 2018 6:43 am
Have you examined your counter shaft sprocket?
Yes and it looks like new.
Interesting. Crap rear sprocket.

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