Chain breaking issues

James T

Help, I snapped my chain 4 times at Llandegla yesterday. What are the common causes of chains snapping, starting with user endured failure and moving to more mechanical type causes, so I can try and identify the cause?

I have an SRAM X9 9 speed group set and SRAM chain.

Kind regards

James

JBA

Not riding in the gear extremes are you? i.e. big chainring - largest sprocket or granny ring - smallest sprocket.

James T

Good starting point. I tried not to but can't rule it out - I will pay more attention next time. I've never had any issues on my road bike!

What's next in the hierarchy?

cooldad

How did you join it after each break?
Were they all the same link?
Any bent teeth on rings or cogs?
Do you have legs like the Hulk?

James T

No quick links with me so progressively shortened the chain and ended up single speed. Could be each repair weakened the chain and shortening increased strain - kind of a vicious spiral of death.

I will check the chain rings. Can the rear mech cause chain failure?

The Rookie

Joining a chain with the the original pins is a guarentee of future issues, so you snapped it once and it probably failed at that join a further 3 times...also as a pin comes out the chain bends and weakens the section either side while it's still held by the one sideplate.

Shortening has no effect on strain...unless you went to too big (teeth on wheels) a combo with the shorter chain such that it was pulled tight.

I carry 2 powerlinks as well as about 4 pairs of chain links, also my chain has 2 powerlinks a single inner link apart so I can fix any break properly with minimal impact, thus enjoying the rest of my ride.

cooldad

This^^^.
I carry a couple of quick links and a small section of chain.

James T

Thanks, useful advice. I will get some power links and cannibalise the old chain for some of the "inner" links.

Was considering just carrying a spare chain!

Kind regards

James