[H666]

Hi

So I set off on my normal ride this morning and bang, the inner-chainring failed (see pics).

Does anyone know why this would happen given that the crankset is 6 months old and I have no problems before with these components? I have never heard of this happening so would be interested to hear your views why and how this could occur in such a way.

Cheers

BTW, Would a new inner-chainring be the way to go or a whole new crankset?

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[H666]

Thanks for the advice.
I
Thanks for the advice.

I have now removed the crank and seen that there are only three bolts holding the chainrings on (the 4th must have popped out when it snapped). I removed these three bolts and checked the absent bolt hole thread which is thankfully fine. I have just ordered a new set of bolts and a new 39t ring. I guess that one of the bolts must have worked loose over time. I have never checked the torque of these bolts before so lesson learned….either this or I am putting out too much power B-)

[Batchy]

Your chainset should be
Your chainset should be covered by Shimano’s two year warranty. This is break is highly unusual. Time to dig out your receipt.

[kev-s]

Nice work
Looks like
Nice work B-) B-) B-)

Looks like one of the bolts has worked loose and somehow caused the chain ring to become damaged

If its still under warranty (which it should be) then get it replaced by the shop you bought the crankset from

If you cant find the receipt a new inner chain ring is around £20

The rest of the crank set should be ok but best to check the threads in the crank sets drive arm to be sure

[Author]

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