Why is my new chain noisy ?

[KimBowers]

Hello everyone.

Here's a small problem for your collective consideration if you please.

I've just fitted a new chain to my bike as the old one broke. I was a bit surprised by that as its not done that many miles (2,000 ish) and was not showing any measurable wear.

My problem is that the new chain makes a horrible graunching sound under power.
I fixed the broken link on the old one and re-fitted it as a test, and its nice and quiet.

So why is the new one noisy ?

The chainring looks fine, I've tried different chain tensions and the new chain is exactly the same make and model as the old one.

My bike has a Rohloff hub (it's not a Thorn though) and so has a constant chainline.

Any ideas please  ?

Thanks, Kim.

[JimK]

I don't have the experience to know, but here is a possibility. Maybe your sprocket and/or chainring have worn too much. A new chain on a worn sprocket can be trouble.. not sure if noise is a likely symptom, though!

[peddles]

My conclusion from similar experience was that there will have been some wear ("stretch") in the old chain and the teeth on the chainring will have started to spread to accomodate it. The noise is caused by the mismatch between the new chain links and the teeth. After only 2000 miles the wear on chainring will be minimal and you should find that the new chain will quickly wear sufficiently for it to bed in on the chainring and run silently again. Mine did and has run silently now for a few thousand miles.

[KimBowers]

Thanks for the advice folks.

It turned out to be wear on the rear sprocket. Reversing it has cured my noise.
Peace and quite is resumed 

Cheers,
Kim.