New Chain equals New Sprocket?

[Noeljs]

My bike shop says I must always replace the sprocket when replacing a worn chain. I find it difficult to dispute this advice but equally there is no obvious wear on sprockets as there is on the (stretched) chain and of course the bike shop(s) have a vested interest. Thus it is an act of faith to change the sprocket concurrently. 10 speed Dura Ace sprockets are 3.5 times the cost of a chain making it an expensive exercise. Various options have been advised by friends - buy 2 or 3 chains and swap them every 1000km; don't get a new sprocket, just replace the chain; one even says he has reversed his sprockets and it has worked out OK. I would appreciate any comments.

 

[capwater]

If you replace your chain before it gets to the extremes you should not have to replace your cassette, but if it is very stretched then your cassette is trashed. Easy test; put on a new chain and see how it runs.

 

[Scotty_Dog]

My bike shop says I must always replace the sprocket when replacing a worn chain.

If this is exactly what they said, then I would find a new bike shop. They are lying - plain and simple.

 

[HowardSteele]

I have ridden many miles on the same rear cluster and front chain rings and up to 3 chain changes, if you change the chain before it damages the sprockets you can get away with it.

However i have had an instance where the chain keyed the sprocket or sprocket keyed the chain whatever, I had to change the sprocket due to missing teeth, the LBS recommended I change the chain as well, I didn't take the LBS's word on it and tried it out first, but AS ADVISED it gave me problems until i put on a new chain.

If your rear cassette and drivetrain sprockets look good I’d only go for a new chain, if you experience chain skip or slipping I’d then consider the full hog.

Saying that you'd probably get a better life from your chain if you start with new sprockets.

 

[capwater]

Learn how to measure your chain, replace your chain and swap out cassettes and you'll never have to second guess what the LBS tells you.

 

[otherworld]

Replace your chain BEFORE it’s at the limit of wear. There are lots of places on-line including the Sheldon Brown site that tell you how to do this.

If you clean and maintain the whole drive train properly and replace chains as above you can get through three chains before you need a new cassette and two cassettes (six chains) before you need new chainrings… rule of thumb.

Proper cleaning will get you the best result in terms of how much distance all this is worth but the conditions you ride in make a big difference too. (lots of rain and dirt = more wear)

Your LBS is all BS…. There’s no way you need a new cassette with every new chain unless you are letting your chain go way over its limit.

Jay.

 

[mikesbytes]

If this is exactly what they said, then I would find a new bike shop. They are lying - plain and simple.

I wouldn't say they are lying, a lot of people beleive this, but it is not a hard and fast rule. One of the problems that bike shops have with just changing the chain, is that some of those riders will experience chain slip and be dissatified, so if the bike shop is cautious and gets the customer a new cassette, then the customer will be less likely to be dissatified (assuming they told the customer first).

My bike shop told me that if its still slipping in a week, bring it back and they will put a new cassette on it.

 

[Powerful Pete]

I wouldn't say they are lying, a lot of people beleive this, but it is not a hard and fast rule. One of the problems that bike shops have with just changing the chain, is that some of those riders will experience chain slip and be dissatified, so if the bike shop is cautious and gets the customer a new cassette, then the customer will be less likely to be dissatified ....

Fair enough, but it is the always that bothers me. They might also want to sell you the new cassette...

 

[Doctor Morbius]

I don't buy the always bit either. Dunderheads.

Here's a quick and easy way to keep from trashing a drivetrain.

http://www.nashbar.com/profile.cfm?...and=&sku=17012&storetype=&estoreid=&pagename=

 

[mitosis]

Another way of checking your chain wear is to compare it to a length of new chain of the same type. Any more than 1% longer and its new chain time.

My most respected adviser on this topic suggests new chains every 3000 k's. I change about every 4000 k's and my sprockets, after 3 chains still look OK.