new sprocket?

[Canonball]

recently i've noticed a strange noise almost every time i decelerate, sounded like something to do with the chain. so i checked it out the other day and the chain was WAY loose. i'm actually surprised that it hadn't flopped off yet. anyway, a couple of friends and i were adjusting it and noticed that the sprocket seems like its not exactly round. i can adjust the chain so that it has the specified amount of freeplay but if i rotate the wheel (and chain) a little and check it in another spot its super tight. so i had to compromise so that the tight spot had some freeplay which made the normal(?) spot looser than i would like. this a common problem? does it seem like a new sprocket would fix it? what sprockets would be recommended? 

[joshr08]

im not a pro on this and im sure someone will correct me if im wrong but chains dont streach evenly and this couses the tight and loose spots in the chain its actually has nothing to do with your sprockets.  if its too bad youll need to replace the chain tho.

[gsJack]

Chains do wear somewhat unevenly towards the end of their life but I've found most of that uneven chain feeeplay is due to kinking links, if you look closely you can see them.  The seals are worn out and the grease gone and the link pins are getting corroded and sticking.

I have a kinky chain every spring since I ride it thru the winter here in NE Ohio and flush the grease out with much salt water thru the worn seals.  Mine was particularly bad early this year and I drowned it with WD40 and lubed it to get it freed up enough to run it thru another month of salt water streets before putting the new chain and front sprocket on.  It's on now so bike will be parked until the approaching April snow is gone.

If you have a clicking noise on the over run with a good chain it's a worn front sprocket assuming adjustment isn't too far off.

[Canonball]

i'm planning on changing oil/filter and cleaning/lubing chain tomorrow so i'll see how she runs after that....i'll report back here then......

[5thAve]

+1 on Jack's reply. Kinking links. Soak the whole chain in some kinda penetrating oil (I wouldn't necessarily do this with a new chain, but you're near the end of chain life anyway). That will free up the links. Get ready to buy a new chain soon. Consider sprocket replacement (at least the front one) at the same time.

[bill14224]

I had the exact same problem he's describing without any kinked links or worn sprockets.  The chain was less than a year old.  It had 4,000 miles on it.  It was a cheap non-O-ring chain the PO put on along with new sprockets just prior to selling the bike to me.  It looked fine, but it wasn't.  It was wearing unevenly, despite being oiled weekly.  After 3 adjustments, I couldn't find a compromise between too tight in one place and too loose in another.  I feel your pain!

cheap non-O-ring chains

The clicking sound you hear is the front sprocket binding on the rollers as the more-worn area of the chain travels over the rear sprocket, riding-up on the sprocket, making the chain at that moment too tight.

[jeremy_nash]

if the chain was adjusted too tight, when the suspension compresses, it can stretch a part of the chain,  I would replace the chain.  my local dealer has oring chains for $60

[qwertydude]

I second nash here, same problem happened on my original chain, I adjusted it too tight once, hit a bump hard and bottomed out and ever since the chain had a bad loose section and was near impossible to adjust, good thing the chain was near the end of it's life. From then on I've learned keep the chain on the loose side and it'll last longer. I got the bike at only 4000 miles and its OEM chain was 1/3 into it's adjustment, probably from being kept too tight. I got a cheapo KMC o-ring on ebay for 40 bucks and 14,000 miles later I'm less than a 1/4 of the adjustment through. On it's sidestand I adjust for 1 inch of freeplay.