Damaged Middle Ring?

[Fubar]

I've had a bit of problem lately changing in/out of the middle chainring on my Triban 3, I turned it upside to have a wee look and there appears to be damage (see attached and a closeup) - however I'm not sure whether this is run of the mill wear and tear and the rear change problem is something else, or if this is something more serious that warrants attention. I have a feeling that the chainring needs replaced (I assume you can just change the middle one?), if so how big a job? Cheers for any advice, Mark

 

[fossyant]

They look well worn, and that may be your problem. Now replacement chain rings aren't dead cheap - cheapest is usually Ribble cycles.

 

[Fubar]

They look well worn, and that may be your problem. Now replacement chain rings aren't dead cheap - cheapest is usually Ribble cycles.

Thanks, how big a job to replace do you reckon?

 

[fossyant]

Easy - 10 minutes Just undo the crank bolts and slip off the big one, then the middle. You may need a special crank bolt holder, but you can usually get away without one and just an allen key. You'll just leave the granny ring on as that bolts on from the non-drive side.

I should think they are 130 BCD (bolt circle diameter) on a shimano compatible tripple - but check - usually have something engraved or printed on the larger chain ring.

 

[byegad]

Yes well shot, the teeth on the ring below the chain are shark finned, definitely new chainrings and chain and likely new cassette too. Next time change the chain at 0.75% worn and it'll just be the chain to replace. I got 3-4 chains to a cassette and 2-3 cassettes to the middle chainring (Which got the most use.) on my commuter. I only ever needed one outer ring in 9 years of commuting.

 

[Fubar]

Easy - 10 minutes Just undo the crank bolts and slip off the big one, then the middle. You may need a special crank bolt holder, but you can usually get away without one and just an allen key. You'll just leave the granny ring on as that bolts on from the non-drive side.

I should think they are 130 BCD (bolt circle diameter) on a shimano compatible tripple - but check - usually have something engraved or printed on the larger chain ring.

Yup, 130 BCD with 50/39/30 written opposite? They are Prowheel make, which I've read are a cheap Chinese-maker.