"3 chains to a cassette" ?

[Euan Uzami]

my mate reckons the advantage of a park tool chain checker is that if you change the chain as soon as it's 0.75% worn, you only need to change the cassette every 3 chains, as opposed to always changing the chain and cassette together.


anybody have any firm opinions as to yay or nay?

[hatler]

Sorry, no. Not yet. I'll be able to verify if this is the case in about two years time.

New bike an' everyfink. 10 speed 105.

One year on. 3000 miles. First chain just chucked at a little over the 0.75.

[urban_biker]

I think I'm probably on about 4 or 5 chains with the same rear sprocket. It seems to be OK so far.

Toothgrinder will be the man to ask.

[Tim]

Does this mean on a 'bent where you fit three chains at a time you can get 9 chains to a cassette?

[Greenbank]

my mate reckons the advantage of a park tool chain checker is that if you change the chain as soon as it's 0.75% worn, you only need to change the cassette every 3 chains, as opposed to always changing the chain and cassette together.

anybody have any firm opinions as to yay or nay?

3 chains in rotation, don't bother waiting until it's worn a certain amount, just [sic] cycle through them regularly.

If you do a monthly maintenance check and take the chain off, use that opportunity to put the next one on. You can then clean the one you've taken off at your leisure ready for 2 months time.

I'm lazy with maintenance, and the geared bike rarely ever gets used (Panoramix has done 1/3 of the mileage on my geared Audax bike when he borrowed it for LEL!).

I don't bother for the fixed, everything just wears together and you can get away with a lot more wear. I suppose I should practice what I preach though, maybe I'll start doing it this weekend when I service the fixed bike.

[iakobski]

I think I'm probably on about 4 or 5 chains with the same rear sprocket. It seems to be OK so far.

Toothgrinder will be the man to ask.

Except he doesn't use cassettes...

[Euan Uzami]

my mate reckons the advantage of a park tool chain checker is that if you change the chain as soon as it's 0.75% worn, you only need to change the cassette every 3 chains, as opposed to always changing the chain and cassette together.

anybody have any firm opinions as to yay or nay?

3 chains in rotation, don't bother waiting until it's worn a certain amount, just [sic] cycle through them regularly.

If you do a monthly maintenance check and take the chain off, use that opportunity to put the next one on. You can then clean the one you've taken off at your leisure ready for 2 months time.

I'm lazy with maintenance, and the geared bike rarely ever gets used (Panoramix has done 1/3 of the mileage on my geared Audax bike when he borrowed it for LEL!).

I don't bother for the fixed, everything just wears together and you can get away with a lot more wear. I suppose I should practice what I preach though, maybe I'll start doing it this weekend when I service the fixed bike.

think it's 'cos a stretched chain copes less well with the additional stress that changing gear puts on it.

I've never understood the 'cycle through chains' philosophy though, because you obviously wear chain at the same rate, so it's no better to get through a chain in x  months than 3 chains in 3x months - therefore it's no cheaper in terms of the amount of money you actually spend on chains. But does it have any advantages in terms of cassette wear? or is it just simply that you get the chance to clean one thoroughly while the other's on the bike?

[clarion]

It will have a slowing effect on the sprocket wear, because the move to long links will be slowed.

I wish I were that organised.

[TheLurker]

...if you change the chain as soon as it's 0.75% worn, you only need to change the cassette every 3 chains, as opposed to always changing the chain and cassette together.

It's a rule of thumb.   It'll vary with each cyclist, the way the use their bike, what sort of maintenance regime they follow and the quality of the parts fitted.  P'raps best to think of it as an indicator of when you should start thinking about replacing the cassette if you're not a 'harsh' rider and are using moderately good quality components.

Me? I can get 4 chains worth of use out of a cassette, but I deep clean chain, cassette and chain rings weekly and I'm not a pedal masher.

[Wendy]

I always use at least 2.5 chains at a time per cassette.

[iakobski]

I've never understood the 'cycle through chains' philosophy though, because you obviously wear chain at the same rate, so it's no better to get through a chain in x  months than 3 chains in 3x months - therefore it's no cheaper in terms of the amount of money you actually spend on chains. But does it have any advantages in terms of cassette wear? or is it just simply that you get the chance to clean one thoroughly while the other's on the bike?

The idea is that a worn chain and a worn cassette will still work together, but a new chain will skip on a worn cassette.

So, if say 5000 miles (say) will wear a chain to the point of destroying the cassette, if you cycle three chains every 1000 miles then you get to 15000 miles before they destroy the cassette. A stretched chain will turn sprockets to sharks fins in very short order, and a new chain will not wear the teeth like that at all.

With that in mind, changing the chain at a specified wear and never riding on a worn chain should give you more than 3 chains per cassette. I don't use cassettes so don't know if they wear in other ways because of the gear changes, but I've used the same sprocket for the last 35,000 km and about 12-15 chains.

[Greenbank]

think it's 'cos a stretched chain copes less well with the additional stress that changing gear puts on it.

Nothing to do with the act of changing gears. The main reason is that you use some sprockets on a cassette more than others, so some wear more than others. A worn chain may work fine on the worn commonly used sprockets, but skip and stutter on the less worn sprockets. Once in this state, replacing the chain only means it works fine on the less worn, less often used sprockets but will skip on the commonly used worn sprockets. That's why you have to replace both if the wear has got too far.

I've never understood the 'cycle through chains' philosophy though, because you obviously wear chain at the same rate, so it's no better to get through a chain in x  months than 3 chains in 3x months - therefore it's no cheaper in terms of the amount of money you actually spend on chains. But does it have any advantages in terms of cassette wear? or is it just simply that you get the chance to clean one thoroughly while the other's on the bike?

Sure, if you replace them before the wear gets too bad (i.e. 0.75%) then there's no real difference. The problem is if you forget and the wear gets too bad then you're beyond the point that you can change chains (otherwise it would start to skip) and you're left with getting the most of that cassette/chain combo until you replace both. Cycling through the regularly should help you prevent this.

[vorsprung]

This time I am on two stainless steel Connex ultra narrow 10 speed chains vs one Campag Centaur 13-29 cassette

The Connex chains have a kind of power link and are easy to remove

I'm rotating them every 1000km or so and hoping that the cassette will last as long as the chains
I don't have a park tool chain stretch measurer.  I wonder if with my patterns of use 2 chains to 1 cassette is right.

Last time I used a campag C10 chain.  After 12 months including that wet PBP it developed a stiff link.  3 months after that it snapped 10 miles from home.  You can't repair ultra narrow 10 speed chains with a chain tool.

[tom_e]

I go for 2:1 on the upright, but that's partly because I don't check it often enough.  3:1 sounds possible if you were diligent enough about checking.

Does this mean on a 'bent where you fit three chains at a time you can get 9 chains to a cassette?

Amusing confusing aside:  
I was hoping the chain wear goes down proportionally with length, because it only runs across a tooth/rotates link under tension proportionally less.  But the cassette will go just as fast.  So I was sort of hoping that the chain and cassette would all synchronise beatifully in their wear and replace everything together at 2-3x a normal chain wear period.  Of course, it'll be painfull then, but I won't look up how much that will cost until I get there  .

Am I deluded?

[Greenbank]

I don't use cassettes so don't know if they wear in other ways because of the gear changes, but I've used the same sprocket for the last 35,000 km and about 12-15 chains.

Fixed sprockets are thicker and made of stronger/heavier material, and therefore harder wearing, than geared sprockets.

[iakobski]

I don't use cassettes so don't know if they wear in other ways because of the gear changes, but I've used the same sprocket for the last 35,000 km and about 12-15 chains.

Fixed sprockets are thicker and made of stronger/heavier material, and therefore harder wearing, than geared sprockets.

True, but a stretched chain will make short work of any cog/sprocket.

[Greenbank]

True, but a stretched chain will make short work of any cog/sprocket.

Indeed, but even with frequent chain swaps, constant cleaning, running as straight a chainline as you can and never changing gears, you'd struggle to get 35,000km out of a sprocket on a standard 9/10/11 speed cassette.

[Euan Uzami]

...

The idea is that a worn chain and a worn cassette will still work together, but a new chain will skip on a worn cassette.

So, if say 5000 miles (say) will wear a chain to the point of destroying the cassette, if you cycle three chains every 1000 miles then you get to 15000 miles before they destroy the cassette. A stretched chain will turn sprockets to sharks fins in very short order, and a new chain will not wear the teeth like that at all.
...

...
Sure, if you replace them before the wear gets too bad (i.e. 0.75%) then there's no real difference. The problem is if you forget and the wear gets too bad then you're beyond the point that you can change chains (otherwise it would start to skip) and you're left with getting the most of that cassette/chain combo until you replace both. Cycling through the regularly should help you prevent this.

ok, I see - so basically, cassette wear is proportional to the worn-ness of the chain it is used with, rather than simply a linear function of how much it has been used with whatever chain.
So going by that principle then, if you had, say, 1,000 chains, and rotated them weekly, then the cassette should last well over 20 years, as by that point it would only have ever been used with chains that were at most a week old?
Or would you say this extrapolation is valid but only up to a point...and it's just that three is a convenient number to buy / keep....

[nuttycyclist]

I think the theory is fine, but in practice I haven't made it work.

I started with 3 chains and one cassette, changing chains every 800 to 900 miles.

After about 4000 miles I'd just changed chain and went out for a ride.  I hit a road that was part of a cycle network (bad planning, I hadn't checked) and as a result the surface was covered in Suffolk sandy dirt washed from the fields and that cars hadn't cleaned away   120 odd miles later and the chain was beyond repair.  It had also worn the cassette sufficiently that neither of the other chains worked either 

So 4000 odd miles of cycling cost me three chains and a cassette.


When I replaced the cassette and chain I decided to just ride them into the ground.  I think I got about 12000 miles out of that, and it was still going ok but just starting to skip on a couple of gears, and as I wanted to do some stupidly long rides I changed the whole lot as a precaution.

Front triple, cassette, chain set me back £90.  That was a lot less than 3 x (3 chains + cassette).

[Greenbank]

I think the theory is fine, but in practice I haven't made it work.

I started with 3 chains and one cassette, changing chains every 800 to 900 miles.

After about 4000 miles I'd just changed chain and went out for a ride.  I hit a road that was part of a cycle network (bad planning, I hadn't checked) and as a result the surface was covered in Suffolk sandy dirt washed from the fields and that cars hadn't cleaned away   120 odd miles later and the chain was beyond repair.  It had also worn the cassette sufficiently that neither of the other chains worked either 

So 4000 odd miles of cycling cost me three chains and a cassette.

Not really. If you'd used just one chain, and gone on that same sandy ride, then you'd be in exactly the same situation.

The two other chains would be perfectly usable on a new cassette as they didn't get screwed over by the sandy ride, so it only cost you one cassette and one (and a bit) chains.

The chain rotation wasn't to blame for the sandy ride destroying the current chain and cassette.

[nuttycyclist]

...
The chain rotation wasn't to blame for the sandy ride destroying the current chain and cassette.

Yup, completely true 


I think I was just upset at having two nearly new chains that were just sufficiently stretched that they wouldn't work on a new cassette.

It made me realise that there is wear there quite soon after I start riding, so instead of wearing out three chains and a cassette I might as well leave the one chain on (and use the cycle maps to make sure I avoid the dirty roads )

[Greenbank]

I think I was just upset at having two nearly new chains that were just sufficiently stretched that they wouldn't work on a new cassette.

And once you've done your first 800 miles or so on the new chain and cassette these two chains should work fine and you can begin the rotation again.

[nuttycyclist]

In theory


In practice it didn't work     (Although... the new chain has a couple of thousand miles on it now, maybe I'll dig them out and have a play.  Thanks for reminding me  )

[MacB]

In theory


In practice it didn't work     (Although... the new chain has a couple of thousand miles on it now, maybe I'll dig them out and have a play.  Thanks for reminding me  )

well I've basically been following your second idea, let it all wear together. I discussed it with the guy that set my bike up for me. 2500 miles and no issues yet, but I'm running 9 speed triple and spend all my time in middle ring. New chain, cassette and middle ring together works out cheaper than regular new chains, by my reckoning.