Chainring wear Vs cassette Vs chains, ratios?

When I was maintaining a fleet of hire bikes we had a 4:2:1 ratio. Each cassette would be changed after its second chain. Chainrings changed after the second cassette.

However, when in that last set, we'd usually run them past the normal wear point. Not quite to destruction - after all, these were being hired out to customers.

As an individual, there's an inevitable bit of variation but our policy was based on averaging out a large sample size.

2 chains per chainring, 1 cassette per 2 chainrings, so 4 chains per cassette (Shimano 12 speed)

Interesting, and thanks for sharing!

I'm currently on 3rd chain (just fitted), 1st cassette and 1st chainring (all Shimano 12speed). Ideally I would had changed the 10T cog, if I could have found them in stock anywhere (due in Feb 2023). Planning to change the cassette with the next chain, but wasn't sure whether to do the chain ring as well.

I've just checked and turns out this system has covered over 3500 km, which doesn't seem all that bad to me.

I suppose if I leave the chainring on too long it could accelerate chain wear, but as long as I catch it before 0.5, it shouldn't cause any knock-on premature wear to the cassette.

Let me open up my app...

Original NX chain lasted 218miles before it got to 0.5%
X01 chain #1 lasted 787 miles before it go to 0.5%
X01 chain #2 has now done 148 miles

GX Cassette and OG chainring have 1144 miles on them.

Shifting is spot on with no issues currently, if shifting stays good then would try a fourth chain.

I’ve just put my fourth chain on the original cassette and chainring of my 2018 bike. This will be the last one, to get me through this winter, then in spring I’m replacing the whole lot as the chainring has part of a tooth missing and I fancy one of those nice 11sp Garbaruk wide ratio cassettes. Not sure what mileage that is but I tended to change chains at .5 on the wear guide thing.

I've a stainless Wolftooth chainring and it's not showing any wear after 2k km. I use GX cassettes and xtr chain.

Change it when it looks worn, i.e. first sign of sharks tooth.

3:1.
So 1 chainring would see 3 cassettes and 9 chains in its life.
Often though, if a chainring needs replacing, I'll run the whole lot into the ground, usually finish it off over winter or a long tour and then replace everything.

A few years ago, I knew the big chainring on my road bike was on its way out so I finished it off completely doing LEJOG on it then changed everything.

For reference my e-bike 12 speed has done about 3500km on a single chain which is still showing between 0.25 and .5 wear  (M9100 chain on SLX cassette) and the cassette 10,000 km so far with zero shifting issues… I rotate two chains and the pair have done about 7000km.

One chainring / one chain / one rear sprocket ( rohloff) 4000+ miles, no appreciable wear

Used to get 3000 miles out of the tandem chains at least ( 9spd)and a cassette every 2nd or 3rd chain with chaininrings replaced once in the whole time I ran it.

2 chains per chainring, 1 cassette per 2 chainrings, so 4 chains per cassette (Shimano 12 speed)

You replace the chainring more often than the cassette?

Yes, chainring is made of a softer material and is permanently engaged with the chain.
New chain on a worn chainring makes a horrible noise and will prematurely wear the new chain.

2 chains per chainring, 1 cassette per 2 chainrings, so 4 chains per cassette (Shimano 12 speed)

Pretty much this, I was surprised to need to do the chainring quite as often on Shimano 12 speed, on my 10 speed setup I think the chainring outlived the frame.

I'd just like to say how much I prefer steel chainrings - minimal weight penalty, usually cheaper, last so much longer.

Steel Shimano one on my Hardtail, XT first replaced with SLX, Burgtec on the Geometron, both seem to last the same amount of time.