Knackered chainrings?

straas

Guru
Put a chain on about 800 miles ago, checked it a few weeks ago and it wasn't at 0.75, but checked again last night and the 1.0 indicator fell right in.

Seems way too early for the chain to be so worn, so I had a look at the chainrings - I'll admit, I never pay any attention to my chainrings, just the chain and casette, so I don't really have a reference point for how they should look, can anyone tell from the below photo if that's excessive wear?

1583914940284.png
 
I’ve seen far worse. Unless it’s chucking the chain off under power, it’ll be fine.
 
Location
Loch side.
I can see some wear on the big ring, but none on the small one. That doesn't mean much though, if we cannot see what position the crank is in. Chainrings don't wear evenly because your powerstroke is uneven.

Zoom out a bit so I can see where the crank lies.
 
OP
S

straas

Guru
I'll try and get a better photo later - no issues with it under power, just wondered if it was the reason I've eaten through a chain in such short order....

A couple of years back when I was (a lot) more lax on maintenance, I rode till the chain snapped on this bike, which may have accelerated the chainring wear.

I'll try a new chain on when I get home - last time the cassette had worn and I had to replace that, if the same thing happens I'm tempted to put this chain back on, buy a new cassette, chainring and chain and just ride it to the death.
 

Ajax Bay

Guru
Location
East Devon
800 miles is a rather short distance for the chain to wear that much, but as others have said elswhere, it does depend on, inter alia, your roads, your riding style, and maintenance regime.
If your current chain is over 0.1% elongated, a new chain on that cassette will skate straightaway. Carry on with the current chain till it skates and then replace chain and cassette together. Don't worry about the chainring(s) (see other thread): as rr says: "Unless it’s chucking the chain off under power, it’ll be fine." Both chainrings look fine to me, btw.
 
Location
Loch side.
I'll try and get a better photo later - no issues with it under power, just wondered if it was the reason I've eaten through a chain in such short order....

A couple of years back when I was (a lot) more lax on maintenance, I rode till the chain snapped on this bike, which may have accelerated the chainring wear.

I'll try a new chain on when I get home - last time the cassette had worn and I had to replace that, if the same thing happens I'm tempted to put this chain back on, buy a new cassette, chainring and chain and just ride it to the death.
Chainrings don't cause issues under power. I wanted to see the rest of the chainring so that I could judge the condition in context. Looking at one small portion of a chainring doesn't tell the whole story.

Worn chainrings don't cause chains to wear any faster. Look for other reasons for your reduced chain life, such as winter conditions or chain hygiene.

You cannot break a bicycle chain by riding it into oblivion. That is physically impossible. Your chain broke because of poor shifting or poor installation.
 
Chainrings don't cause issues under power.
Yes they do, if you’ve got a badly worn chainring, or it’s bent, it will chuck the chain as soon as you put sufficient power through it.
You cannot break a bicycle chain by riding it into oblivion.
Yes you can.
That is physically impossible.
No it isn’t
Your chain broke because of poor shifting or poor installation.
That wouldn’t have helped, but almost certainly wasn’t the sole reason.
 
:sad: The cassette's only been on 800 miles too!
Depending on the quality of the cassette, that shouldn’t cause too many issues if you replace the chain. ‘Best practice’ decrees that you should replace the chain and cassette together, but that’s open to a certain degree of interpretation.
 
OP
S

straas

Guru
I'll put a new chain on later and see if it skips or not, and make a decision then.

I was convinced by the LBS to change my lube to finish line dry teflon, but I feel its attracting quite a bit of grime. I had previously used squirt wax lube and I'm pretty tempted to change back, as I'm sure the chain was cleaner for it.
 
I'll put a new chain on later and see if it skips or not, and make a decision then.

I was convinced by the LBS to change my lube to finish line dry teflon, but I feel its attracting quite a bit of grime. I had previously used squirt wax lube and I'm pretty tempted to change back, as I'm sure the chain was cleaner for it.
Some lubes are better at trapping debris / dirt than others. The only way to find out is by trial and error, on the exact rides that you do.
 

Milkfloat

An Peanut
Location
Midlands
I'll put a new chain on later and see if it skips or not, and make a decision then.

I was convinced by the LBS to change my lube to finish line dry teflon, but I feel its attracting quite a bit of grime. I had previously used squirt wax lube and I'm pretty tempted to change back, as I'm sure the chain was cleaner for it.
Dry lube in winter - that is a big no for me.
 

Ajax Bay

Guru
Location
East Devon
That [poor shifting or poor installation] wouldn’t have helped, but almost certainly wasn’t the sole reason [for the chain breaking].
Care to suggest what other reasons there might be for a chain to break when riding along normally (ie not in a crash) other than poor installation or poor shifting?
 
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