Originally Posted by
Racing Dan
"The chain is a standard singlespeed chain ..."
Is it? Looks like a chain from a moped or go cart.
It came in a sealed SRAM box that said "single speed" so I'd be surprised if it wasn't for a bike. It is definitely wider than a 6/7/8 speed chain
Originally Posted by
79pmooney
I'm betting worn chainring. Look to see if the teeth in line with the cranks are the same shape and width as the teeth at right angles. If they are not identical, the difference is wear. A chain fitting loosely is a worn out ("stretched" chain on a newer chainring.)
Do you still have the old chain? Pull it tight (nothing radical needed; just need to pull out all the play) and measure the distance between pins 12 pairs of links apart with a steel tape measure or ruler. If the length is 12 3/32" or more, there's your answer. A new chain won't run on a cog/chainring that's worn to match a chain that stretched. (Well it might but it will be a poor experience.)
That's a clever way to check the wear. Thank you