New chain = new cassette?

[miloat]

Getting a new chain fitted after about 1800 miles ish well looked after.
Just wondering if I will have to get a new cassete at the same time.
Its 7 speed sora if that means anything.

[Biggsy]

You don't need to fit a new cassette if a new chain works with the old one, and, even if you measure things, you can't be sure of that until you actually try a new chain.  I reckon it's a 50/50 chance after 1800 miles.

Fit the chain and go for a ride, testing all the gears.  Be gentle at first in case the chain skips.  If there's just a tiny little blip occasionally, you might be alright after you've run in the chain for 50-100 miles.  Any more serious problem and you'll need a new cassette.

[Subject title modified to make it more descriptive]

[rogerzilla]

Generally if you change the chain before it gets to 1/16" stretch over a foot, you can re-use the cassette about three times.  Chainrings last much longer still.

I'm on the fourth or fifth chain on my 12-25 cassette, and it doesn't slip or kick.

[Seineseeker]

I almost never change the cassette when I change the chain, they say you should, but it always seems to be ok.

[gonzo]

If the chain skips then you need to change the cassette.

[Seineseeker]

If the chain skips then you need to change the cassette.

QED!

[alchemy]

After reading something written in another place by Biggsy (I think) I've been using three chains with the same cassette and rotating the chains every 1,000km. I seem to get a lot of km from each cassette by doing it this way.

I also clean the chain and cassette regularly which can't do any harm either

[Chris S]

Different experience here - I nearly always have to change the cassette with the chain.

I generally get about 2000/3000km out of a chain before it shows three or four millimeters of stretch. A new chain on the old cassette at this point will almost certainly skip - especially on the "regular" sprockets.

I've always put this down to (a) the sandy/flinty soils in East Anglia that make a great grinding paste, and (b) I'm heavy, but not too slow, so the drive has to work hard. Those of you who are racing snakes will punish your drives much less.

Perhaps I should rotate several chains - must say, I've never tried that.

[Malandro]

I had a new chain put on my tourer last weekend.  It had done 1500 miles from new with many heavily laden and hilly miles.  The guy in the LBS suggested a new cassette was needed too.  When I went to pick the bike up later, he then said I could have got a bit more mileage out of both the chain and the cassette!

I nearly asked for the old cassette back!  Think I'll be doing this type of maintenance myself from now on!

[PhilO]

Different experience here - I nearly always have to change the cassette with the chain.

I generally get about 2000/3000km out of a chain before it shows three or four millimeters of stretch. A new chain on the old cassette at this point will almost certainly skip - especially on the "regular" sprockets.

I've always put this down to (a) the sandy/flinty soils in East Anglia that make a great grinding paste, and (b) I'm heavy, but not too slow, so the drive has to work hard. Those of you who are racing snakes will punish your drives much less.

Perhaps I should rotate several chains - must say, I've never tried that.

As Roger says, 1/16" stretch is about the limit at which you can be sure of not needing to replace the cassette. I find it touch-or-go between there and 1/8", and from 1/8" upwards you can forget it...

3mm ~ 1/8", so I'm not surprised that need to change the cassette. Try swapping the chain a bit earlier (wear accelarates, so you won't need to halve your replacement interval).

Having said that, chains are pretty expensive, so part of me thinks it would be cheaper to just ride the chain into the ground, then replace chain, cassette and rings in one go...

[rogerzilla]

Some fixie riders deliberately ride the whole lot into the ground - ring, chain and sprocket.  Apparently it gets smoother and smoother.  Then it slips and Bad Stuff happens 

[Gattopardo]

So a chain will need replacing before the cassette?

Should the chain and the derailleur jockey wheels be replaced at the same time?

Having just done my rockhoppers chain, cassette, jockey wheels and crank inc bottom bracket as the teeth were all hooked. 

[Biggsy]

So a chain will need replacing before the cassette?

The chain won't need replacing before the cassette, but if you do, and do it soon enough, your cassette and chainrings will last longer.  It can be worth doing when using expensive cassettes and chainrings anyway.  Of course the cost of chains has to be accounted for as well.

The rotation method - I don't believe it's any different in the long run, but does mean you can have a clean & lubed chain ready to fit.

Should the chain and the derailleur jockey wheels be replaced at the same time?

Jockey wheels are less critical and take much less load.  You can wait until they are badly worn.

Chainrings tend to last longer than cassettes.  Like the cassette, you can wait until chainrings don't work with a new chain.

[mrcharly-YHT]

Chainrings are expensive, much more than cassettes and chains.

[rogerzilla]

Unless you buy Warhawk 110BCD fixie rings from the US like I do, then they're one-third the price of an EAI sprocket   

[bobb]

Just play it by ear. Keep everything clean and lubed (what an unpleasant word!) and cables new. If gear shifting is still pig awful - new chain and cassette.

I've tried to get as much life as possible out of my tourer's drive train, but I have to accept defeat and get the credit card out.

As for tools. I don't have much faith in them. My super dooper Park tool told me my blinging new Campg chain was stretched after 1 mile of riding it up and down the road.

If things get crunchy, replace - otherwise leave be......

[Gattopardo]

Sorry to go a bit off topic,

Am I correct in assuming that a worn chain will also have more lateral movement at the pins than a un worn chain?

I cleaned the chain and sprokets off my road bike and the chain seem to have a great deal of lateral movement so was thinking I might as well replace the chain and the rear derailleur cogs to improve the bike.

[Biggsy]

Lateral play helps gear shifting, and even new chains have quite a lot.  A normal amount of wear doesn't increase lateral play much.  If you replace a chain much before what was originally 12" has become 12 1/16", you are wasting money.

You won't notice improvement to the bike by replacing parts before they are worn, other than because they are clean and lubed.  You could just clean and lube the existing parts instead.

[BornAgainCyclist]

Sorry to go a bit off topic,

Am I correct in assuming that a worn chain will also have more lateral movement at the pins than a un worn chain?

I cleaned the chain and sprokets off my road bike and the chain seem to have a great deal of lateral movement so was thinking I might as well replace the chain and the rear derailleur cogs to improve the bike.

Yes, you're right. When we talk about a stretched chain, wot we really mean is a worn chain, (the links don't really stretch).  Each pin wears a small amount and it is this cumulative wear over all the pins that makes the chain longer and have more lateral movement.

[Biggsy]

Lateral play doesn't do any harm, as far as I know.

[Gattopardo]

Lateral play helps gear shifting, and even new chains have quite a lot.  A normal amount of wear doesn't increase lateral play much.  If you replace a chain much before what was originally 12" has become 12 1/16", you are wasting money.

You won't notice improvement to the bike by replacing parts before they are worn, other than because they are clean and lubed.  You could just clean and lube the existing parts instead.

Sorry going off topic but I cleaned the rear cassette and chain, and found that the chain was worn there was visible movement between the chain links.  The new chain that I have has a lot less sideways movement.

[giropaul]

I had a new chain put on my tourer last weekend.  It had done 1500 miles from new with many heavily laden and hilly miles.  The guy in the LBS suggested a new cassette was needed too.  When I went to pick the bike up later, he then said I could have got a bit more mileage out of both the chain and the cassette!

I nearly asked for the old cassette back!  Think I'll be doing this type of maintenance myself from now on!

What if he hadn't replaced the cassette and it slipped, and you went over the bars and lost your front teeth?

Shops have to err on the side of caution in case of liability.

[mattc]

For the penny-pinchers ...
If one replaces the chain in it's "middle age", and the new one skips, but the cassette looks usable ...
Is there a zone where the old cassette could be saved for use with "part-worn" chains? e.g. put 1000km on the new chain, then swap the old block back in?

You're then back into a possible 3-chains-1-block rotation system,
plus you have a slightly worn cassette waiting to be .... oh this is sounding too complicated!

[Gattopardo]

I had a new chain put on my tourer last weekend.  It had done 1500 miles from new with many heavily laden and hilly miles.  The guy in the LBS suggested a new cassette was needed too.  When I went to pick the bike up later, he then said I could have got a bit more mileage out of both the chain and the cassette!

I nearly asked for the old cassette back!  Think I'll be doing this type of maintenance myself from now on!

What if he hadn't replaced the cassette and it slipped, and you went over the bars and lost your front teeth?

Shops have to err on the side of caution in case of liability.

In my case the cassette on one road bike was fine when cleaned thourughly.  I thing the previous owner used motorcyle chain wax on it,  but the chain looked worn when I cleaned it thourogly with parraffin but before then the chain wasn't slipping.  The MTB on the other hand had worn bottom bracket and cassette and chain rings were past there best so decided to do the whole lot.

[Biggsy]

OK, sideways movement increases with wear, but it doesn't matter, and is nowhere near a fine enough way of judging wear.  To gauge chain wear accurately you need to measure length (while it is under load, eg. while pulling on it).