Rohloff drivetrain wear: when to replace chain, sprocket, chainring?

[Chris2020]

Hello, 
I’m a 1st time Rohloff owner. Thorn nomad mk3
5 years old  22000km

Minimal maintenance other than yearly oil change and very occasional cleaning and oiling. No chainglider
EBB at max adjustments. Ie.
chain at the pont when I would need remove links.
I am wondering when would be the point to either replace the chain,  replace or flip the chainring and/or sprocket?
Any advice would be much appreciated.
Thanks
Chris

[UKTony]

I take it from what you say that the slack in the chain has already reached the point where adjustment is necessary but there’s no adjustment remaining on the eccentric.

Rohloff recommend a new chain is fitted after reversing a sprocket.

I don’t know how successful taking a link out of the chain would be because I’ve never done it. If it was me I’d simply flip the sprocket, and the chainring, then fit a new chain.

[JohnR]

I think that with a straight chainline then the chain can be fairly slack without the risk of it coming off. However, if it's a long time since the chain was last replaced then I would first replace the chain (single speed chains are reasonably priced) and see how will it runs. If it isn't happy then flip the sprocket and chainring.

[Chris2020]

I take it from what you say that the slack in the chain has already reached the point where adjustment is necessary but there’s no adjustment remaining on the eccentric.

Yes, and it's come off a couple of times now. The chain has never been replaced. I did buy a replacement at some point but haven't swapped it yet, but from what I understand now would be the time to do so.

[PH]

You might eek out another few thousand km's by taking a link out, but the failure method becomes more and more likely to be a snapped chain.  I'd consider I'd had good value from it. flip both chainring and sprocket and fit the new chain.    I don't always get the same distance out of the second side of a chainring and sprockets, maybe 70%, but yours don't look as worn mine usually do at that mileage.  Even at 70% that's nearly 40k km from a chainring, sprocket and two chains, that'll turn most people running a derailleur green with envy.

[Chris2020]

Thank for your reply. That is kind of the feeling I had but as I’ve never been at this point before, part of me does want to see how long I can get out of one chain. As you say compared to my previous derailleur bike it’s really hard to fathom!

[martinf]

You might eek out another few thousand km's by taking a link out, but the failure method becomes more and more likely to be a snapped chain.  I'd consider I'd had good value from it. flip both chainring and sprocket and fit the new chain.

Agree. After 22000 km and given the wear on the chainring, time for a new chain and flip the sprocket and chainring.

Snapping a chain could be very inconvenient.

On a hub gear bike I have had this happen once, the outer plates on one link failed on a very worn chain, but nothing like 22000 kms use. This was before I started using Chaingliders, which make a significant difference to transmission maintenance and longevity, at least for all-weather use in the coastal area where I live.

Fortunately for me I was only a few kms from home and the bike trailer I was towing had been unloaded before the chain broke. So not too hard to push the bike/trailer up the hills and coast on the downhills. My bike toolkit now includes spare 1/8" chain links in addition to the 3/32" quick links and spare links I already had.

[Andyb1]

Strange how the chainwheel is more worn than the sprocket - but maybe it is alloy while the sprocket is steel?
With teeth starting to hook is there a risk of the chain being sucked up the back of the chainwheel and locking up? 

Out of interest, what make /model of chain is it?    I think Thorn used to fit KMC X1 chains which have a good reputation for long life but were not cheap.