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How do my teeth look?

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New chain fitted at almost 0.75 after 4500+ miles and 23 months under a Chainglider.

KMC X1  110 LINKS 3/31 Inch taken off and same replaced.

Counted the links and 99 agreed with previous notes.

How do my teeth look?
Ring and sprocket both new in October 2014, 19,400 miles ago. Under the Chainglider.

I haven't flipped them.

Andre Jute:
For a moment there I thought, Matt will have to join me in the dunces' corner reserved for chain wreckers and other mashers. Then I saw your chain did 4500 miles as distinct from the 4506 kilometres I reached on a KMC X8 when I threw it off at 0.5 on the checker.

Your mileage is a good 62% better than I achieved on what I considered a good life for the chain, and still a little better than if I had run that chain to 0.75.

Your teeth look good to me. I wonder though if there isn't a case for flipping the cogs to ensure even wear.

19,400 miles on a set of cogs, hardly worn!

I flipped my sprocket when it had maybe twice as much wear as yours, or possibly three times as much.

Just looking at a sprocket, it is hard to judge amount of wear.  But, the holes in the sprocket lined up initially with the teeth, and that makes it easier to judge wear.  If you specifically look just at one tooth and the adjacent sprocket hole, it becomes quite clear that on one side of the tooth, there is less metal between that hole and the sprocket cutout than there is on the other side of the tooth.  That shows how much metal has worn away.

Unfortunately your camera autofocused on the spoke heads, not on the sprocket, making it a bit harder to see.

The photo I attached is of my sprocket before I flipped it.  I run an sprocket with an even number of teeth (16 teeth) so every other tooth wears a bit different on mine.  I assume yours is a 17T which is what Thorn typically fitted, thus each tooth on your sprocket should wear exactly the same way.

I have concluded that it does not hurt any to run chains a bit longer on a Rohloff than on a derailleur system bike, other than sprocket and chainring wear.  But I have an even number of teeth on both my chainring and sprocket, so the teeth wear to match the chain wear, as every other chain link gets longer while the other chain links stay the same length.

I have decided that when my derailleur chains reach 0.75 percent elongation, I will set them aside to put on my Rohloff.  I am only putting new chains on derailleur bikes.  At this time I have three chains with 0.75 percent elongation waiting to be fitted to my Rohloff.  I need to ride my Rohloff bike more often, I replaced two derailleur chains last year.

I am about to hit 11,000km on a flipped socket and chain. I can tell you now that my photos do not look as unworn as yours. The bike was purchased with an estimate of 10,000km on it and sprocket / chainring are looking haggard. But only the last 5k had a Chainglider and I am convinced that most of the serious wear happened before it was fitted and exposed to the elements.

Iíll post pics in the next couple of weeks when I do the service.

Look fine to me, certainly wouldn't have considered changing the chain, but we do this one regularly...
My chains are on, 3,600, 4,900 and 7,200 miles, I haven't measured them, but I'm not expecting to replace any of them for a long while yet.


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