44T Thorn single speed chainring - one broken tooth, ok to use?

[tt2cycletours]

Please see picture of a chainring I am hoping to use on my first Rohloff bike... I am fixing up a German made Hercules Trekking Division touring bike, and was wondering if it would be unwise to at least use this in the short term.  I did break the tooth off at some point, can't remember what happened.

I think it is fair to say there is plenty of wear left in the chainring, and I guess this will still have more traction on the chain than a complete 36 tooth equivalent.

I am planning to use this in conjunction with a 21 tooth sprocket, to achieve a gear ratio of 2.1, well above the now allowed 1.9 although I will be using 200mm cranks.  I am not intending to carry heavy loads on this bike.

I have an order of bits and bobs on the way from SJSC tomorrow, so could make a last minute amendment if necessary.  Thanks.

[mickeg]

If it was me and I really needed to use the bike, I might try it with plans for no more than a few hundred km.  But not thousands.  If your chain is fairly new, it will probably work without any problems at all, but if your chain has a lot of elongation, every revolution might sound a bit odd as it skips that tooth.

Sometimes you see photos of antique bikes or see them in museums that had a tooth every other link.  I do not know why they sometimes did it that way over a century ago.

Note that every other tooth on your chainring seems to have more wear on the side, those would be the teeth that had the chain links with inner plates most of the time.  I suggest that you put the chain on it the same way as before, the teeth with more side wear should have the teeth with inner links. 

I put a small notch in one tooth on my Rohloff bike, I always put the chain on so that the tooth with a notch has a chainlink with outer plates.  More on that here:
https://www.sheldonbrown.com/chain-life.html

[tt2cycletours]

Thanks for the quick reply, advice noted, I wasn't aware of the issue of inner and outer plate sections of chains effecting chainring wear - good to know.

[mickeg]

Thanks for the quick reply, advice noted, I wasn't aware of the issue of inner and outer plate sections of chains effecting chainring wear - good to know.

Glad to help.  Photo from my rear sprocket (16 teeth) last year before I flipped it over, it is pretty clear which tooth had the side plate wear.

[PH]

Is the decision made?
It'd probably be alright as long as you had a perfect chainline and a frame not likely to flex much.  The missing tooth provides a perfect gate for the chain to escape through, one plate the wrong side of the adjoining tooth and they'll all follow...  I might use it on a commuting bike, probably running the chain with less slack than otherwise, I probably wouldn't if I was likely to be far from home.
Alternatively - Depending on the chainset and bikes use, you might also consider bashguards, double sided would mean the chain never coming off and even a single sided would stop it happening again.