Originally Posted by
DaveSSS
ABsolutely wrong. That's why I deliberately used a Campy chain for 6000 miles - to test Jobst Brandt's contention that only elongation would cause sprocket damage. My chain had no more than .25% elongation, but two of the most-used sprockets skipped with a new chain. Campy rollers don't wear faster than others. Their inner plates and pins wear far less than any other brand. I used a cheap kimc 11.93 chain for only 1000 miles and had .25% elongation.
The smartest thing to do is alternate the use of several chains, so the sprockets don't wear-in to match small rollers or an elongated chain.
Since I am absolutely wrong, I would like to hear an explanation from you of how roller wear causes cog wear.
It is fairly straightforward to me. The chain wears before the cogs, The pitch of the cog teeth and the elongated chain don't match so there is friction and the cog teeth will wear to match the pitch of the chain. This happens where the chain is under tension - as it goes onto the sprocket and as it comes off.