Originally Posted by seely
I'd have to disagree with Mr. Brown. While I know the chain does not literaly stretch like an elastic band, I think it does enlongate over time. .
Only a fool would disagree with Sheldon (bike-wise that is). you didn't mention if you put chain lube on the chain, you didn't mention if you put a new cog on either.
a new chain (even a crappy one like KMC) will wear faster with an old cog, no lube and a super tight chain. you did sooo many things wrong. what size chain ring and cogs are you running? cogs that are smaller than 16T are known for jumping the chain off easier. a short wheel base will help make it jump aswell. even if your chain did get really really stretch out that wouldn't be enough of a cause for it to jump, it needs another force.
get a brake if you don't know what your doing.