himespau 

I know this sounds a bit odd, but hear me out.

After I got hit last year (took me 5-6 months to recover and I'm not still 100% there), I have done almost all my riding indoors (like 7800 out of 8000 km as a rough estimate to give you an idea). Because I have cats who are very jealous and rub up against my bike whenever they seeing me getting my kit on, I've switched to using hot wax to lubricate my chains rather than the oil-based lubes I used to use (not trying to start a chain lube thread), so that my wife doesn't get upset because of cats with oily fur tracking it through the house. I have 3 chains that I rotate between every 500-1000 km.

I've recently started working on building up a 2nd bike so that I don't have to take one off the trainer and put wheels on it and stuff when I want to ride outdoors. The new (to me - it's a ~26 year-old Merckx) is Ti, so it's probably going to be my indoor rider to save my beautiful steel Colnago from more corrosive sweat exposure (I do wipe it down after every ride, but indoors means lots of sweat and maybe not the best evaporation, so I worry). Because I was planning on doing the Merckx Ti indoors, I stripped and pre-waxed 3 more chains for it. The plan was to keep the 3 waxed chain rotation for my Colnago when I ride it outside as well in case I decide to ride it inside later.

After fitting and cutting the first of the waxed chains for the Merckx today, out of random curiosity, I took it over and held it up next to one of the chains for the Colnago that was waiting for another trip through the wax bath. I was a bit surprised to see it was the same length (maybe I shouldn't have been, both are road race bikes from the same era, so similar geometries and both have 10 speed triples with medium cage Centaur rear derailleurs - the only difference is the chainrings on the Merckx are 2 teeth bigger on each ring).

I then got to thinking, if the chains are all the same length (and I held the new chain for the Merckx next to chain that's in the rotation for the Colnago and didn't see any significant length difference - I didn't lay them out and specifically measure), is there any reason I can't just put the 3 chains that I've got for each bike into one common pool and rotate through all 6 of them every time I need to change? The one thing I can see is that the Colnago chains each have ~2500 km on them, and going forward, if it's outside the Colnago won't get as much use, so all the chains would spend more time on the Merckx and over time would stretch to match that cassette.

Since they require the same length, can I keep them together, or is it in the best interest of both of my drive trains to keep track of which chains go with which bike and hang them separately in my parts closet?

SoSmellyAir

I might consider lazily transferring a nearly new, lightly used chain from one bike to another bike once, e.g., to avoid the deep cleaning regiment required to prepare a chain for the initial wax. However, for long term usage, I would keep the chain(s) for each bike separate. Even if both bikes use the exact same chain length, the chain may wear differently on each bike, and I would prefer the drivetrain components of each bike to wear together, rather than moving a chain back and forth and risk introducing strange wear patterns in the drivetrain of either bike.

himespau 

Yeah, I kind of figured it wouldn't be a good idea (all the chains are already cleaned and waxed. I was just wanting to be lazy and store them all on a single nail rather than pounding a second nail in and labeling the nails. For the cost of a cheap nail and a little marker, it's probably better not to risk putting extra wear on the drive train. That'd be the definition of "penny wise, but pound stupid".

jccaclimber

A side effect of asking an uncommon question is that part of the collective user base will err on the side of caution and come up with potential issues.

Putting this a different way, is swapping one chain between two bikes much different than swapping multiple cassettes/wheels into one bike? That’s something many people here do, and without dedicating a different chain to each wheel.

Edit, and this is just a curiosity, I wonder if a chain used only indoors on a trainer would have a longer life due to not experiencing as much road grit? If most wear particles come from gradual chain breakdown it wouldn’t matter, and if they come from outside sources it might. How does this compare to outdoor bikes with well enclosed chain guards, if such a thing still exists in any real numbers? I wouldn’t let that stop me from swapping the chains, but that’s just me.

Atlas Shrugged

Common sense tells me to rotate in a structure fashion as long as you ride both bikes equally. However I am winging it on this one and hope cxwrench responds as his experience might be helpful.

3alarmer 

.
...I do this with chain saw chains, and it works out fine. I only pay about ten bucks for a KMC bike chain, though, and they don't get dull and need sharpening. So I just leave them on the bike. One alternative you might not have considered, is shaving the cats.

himespau 

70sSanO

I don’t see a problem with rotating multiple chains on multiple bikes. It would be prudent to monitor chain and cassette wear over the bikes.

As jccaclimber pointed out people swap out training and racing wheels and are using different cassettes, so I wouldn’t think there would be a problem.

John

easyupbug 

I suspect a tiny improvement of in chain life by rotation. THis from a truely stupid example in my experience with a copper converter which holds a couple hundred tonnes of molten copper we would adjust or replace a pinion and see ever so slightly a change in the wear pattern on the bull gear and a just perceptible longer life of the bull gear.

squirtdad

Moral of story: Cats cause problems, the little furball monsters (as mine tries to help me type)

Try it and see if you notice any issues with shifting performance, If you do stop swapping, if you don't keep at it



p.s. mods we need a cat on a bike emoji