Replacing only rear sprocket?

[Gazza M]

I'm running a renthal rear sprocket that is on its last legs at the moment - the teeth are starting to hook a fair bit so that needs replacing.

Question is, do I replace the front sprocket and chain as well? I know the other way round is a no-no (new chain/old sprockets), but haven't found too much info about just replacing the rear. It makes sense the renthal wearing fast as it's ally, so I its life would be much shorter than the front and chain.

Chain looks OK to me - standard/service limit for 20 link length is 317.5/323mm and I measured mine as 319-320mm. Front sprocket is looking OK too.

Price is really the issue here - another renthal sprocket on its own is £38, adding chain and front to that takes it up to £129. Another issue is the bike is a ZRX1100 with ZXR750 wheels on it so I can't just buy a c/s kit as hole PCDs are different.

Any thoughts?
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Past: '07 YBR125, '00 GPZ500S, '99 ZRX1100, '98 CBR600 track bike, '97 ZX9R
Present: '05 R6 track bike, 140 pit bike

[Kickstart]

Hi

Main reason it is a no-no is because the worn bits will rapidly wear the new bits which wastes a bit of money (especially worn cheap sprockets with a new expensive chain).

Alloy sprockets often wear quickly so in your case I would certainly seriously consider just putting on a new rear sprocket. But probably a far cheaper and longer lasting steel one

All the best

K
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Gazza M]

Yeah that's what I'm thinking, although might go with another Renthal as I'm a tart only a tenner more expensive than a steel one

I reckon by the time that one's done I'll have to replace everything anyways
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Past: '07 YBR125, '00 GPZ500S, '99 ZRX1100, '98 CBR600 track bike, '97 ZX9R
Present: '05 R6 track bike, 140 pit bike

[Boris the spider]

I have changed Renthal rears only before. As like you, bit of a tart.
Never had any issues.
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Yes I'm a pig....And yes... The working public do pay my wages. Tho I contribute to your benefits you lazy c##t. You do not pay my wages. So go fcuk yourself.

[Snod Blatter]

If it has not hooked terribly and isn't attacking the chain, and everything else seems fine, I can't see a problem with it. Even if it wears quickly you'll get extra life out of your current stuff.

My chain is on its third front sprocket and will soon see a replacement rear sprocket at 22K, the chain itself is not stretching or showing any sign of being worn out. Sprockets are cheap and easy to fit so why not..?
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1994 CB250, 1984 CBX250RS-E, 1989 K100RS, 1995 TRX850, 2016 Z250SL

[Az]