Sprocket Consult Please

[nhchris]

I was wondering if some of you road dogs could take a look at the photos below and give me your opinion of these sprockets.

Should I replacement them with only 12k miles on the bike or just go for a new chain??? 

Thanks

[duhs10]

Rear sprocket looks pretty good... front sprocket has some wear. Most will say to replace both sprockets with the chain.  You could probably get away without replacing the rear, but I would replace the front when you replace the chain.

[skipperT]

Agree with Duhs10, however I would still consider a rear. Attempt to pull your chain off the sprocket and see how much movement there is - anything around 1-2 mm’s shows some wear on the rear as well. Front OEM sprocket is cheap, $20-30 usd. Rear is under a hundred I believe.

order a new nut also for the output shaft (it’s staked)  

-Skip

[BBB]

As you’re going to the effort of replacing the chain, I would do both sprockets. The front has worn as the left and right tooth profiles are different, which is not surprising as it rotates faster than the rear sprocket. You’ll have peace of mind that all is new and gives your chain the best chance of longevity.

You’ll find you have the choice of damped (like OEM) or undamped for the front. I went for undamped and can’t notice the difference. Don’t forget the front sprocket nut as @skipperT mentioned, which as far as I could find, was a Yamaha dealer part. Some forum users have reused them.