I've got my wheels off at the moment and I've long fancied a Renthal lightweight anodised sprocket jobby. Largely for cosmetic reasons if I'm honest. I figured since I've got the thing in pieces and since I can get the sprocket for under £40 that I might stick one on there. The other times that I've replaced sprockets I've done both at the same time and the chain too. There are reasons why I can't replace the front sprocket right now but I don't want to bore you with the details so the simple question is, is it OK to just replace the rear?
If the front sprocket is worn it will wear the new one quicker than normal I expect. I'm sure someone will say I'm wrong though...
I thought it might cause uneven wear but at less than 40 quid I figured it's not the end of the world if it did.
I've always thought it's best to replace both sprockets and chain at the same time as they wear together. Replacing one piece of the set means it doesn't fit quite right and therefore wears quicker than it would do normally. Other than the sprocket not lasting quite as long as it might there's no real danger in it.
If the chain is in good condition it won't hurt to chance just one sprocket. Remember, the front does three times as much work as the rear anyway. It's a worn chain that will damage your new sprocket. If the old one is still okay, why not try a different size, +1 or +2? You might enjoy slightly less top speed but better acceleration.
I did think about that but I figured that my chain might not be long enough to accommodate the larger sprocket.
I have +2 rear sprocket with stock chain (it's quite a tight fit though). P.S. "Cosmetic reasons"? - No-one can see your sprocket when the bike is moving!
I can see it when it's stood still and I know it's there when I'm riding it. I don't do things for other people's benefits
