Replace the chain

[brotherdarryl]

I was out riding today on my mtb and the chain broke. thankfully had a chain tool to fix it, so carried on riding. It broke quite a while back and fixed it then as well. But i recon it is time for a new chain, what i want to know is if there is a rule of thumb or a way to tell if i must replace the cassette as well? I always thought the one must be replaced with the other, but someone told me not necessarily. Is it like replace the tyres on your car and not doing the wheel alignment?

[covie]

If your chain is old and by it breaking twice I am assuming it is, get ready to replace the chain, the rear sprocket, and all your rings on your crank. Since the chain would have bonded with all of them and misformed the teeth to the chains profile.

 

Well thats if the drivetrain has seen enough mileage.

[kosmonooit]

The chain will start to break when its really down the line, but don't wait for that, there are other ways of measuring wear of a chain. A popular one is a (Park) measuring tool that shows you if the amount of wear is within limits, although some here are adamant that technique is inaccurate. All you must do is ensure the chain is clean before measuring. But a chain can break by bad shifting and other reasons.

 

As for cassettes and sprockets, replace them after an inspection tells you they need replacing: you will see when they are worn. Replacing them with every chain is one the biggest LBS cons out there.

 

And check out PowerLinks whilst you are about it.

Edited December 19, 2010 by kosmonooit

[rouxtjie]

kosmonooit is right, friend of mine broker her brand new xtr chain on first outing with it, a shift under pressure ie. the lateral stress that caused it.

 

I use park's measuring tool, calculating the wear with an inch ruler might be more accurate but a bigger schlep. As far as cassettes go, I replace it after three chains have been through it works for me.

[Mojoman]

I was out riding today on my mtb and the chain broke. thankfully had a chain tool to fix it, so carried on riding. It broke quite a while back and fixed it then as well. But i recon it is time for a new chain, what i want to know is if there is a rule of thumb or a way to tell if i must replace the cassette as well? I always thought the one must be replaced with the other, but someone told me not necessarily. Is it like replace the tyres on your car and not doing the wheel alignment?

How many K's has the chain and cassette etc done? I am about to replace my drivetrain (including the rear derailer wheels, have you seen the price of those bits of plastic!) and will try using two chains, swop them over every couple of rides and see how that goes.

[dirtrider]

Can't really remember the last time I replaced a chain . I did replace crankset yesterday but only because I put a two blade setup on the bike . But why do we replace the chain every x km ? Does the chain break often ? Gear changing is affected ? Chain suck occurs ? Or your park tool thinks it is time ?

 

If your chain breaks then either you not treating it right or it is just a sheeet chain .

Have never seen a worn DT affecting gear changes , but maybe I don't really change gears that much

Chain suck is also not result of worn DT . You can get chainsuck on brand new setups

Park tool , whatever

[covie]

Have never seen a worn DT affecting gear changes

 

I have replaced my crankset the other day, and no matter what i did it would keep slipping of the middle cogs on my rear cassette, Sent the bike into the shop and they could not sort it out either, so bought a new chain, to go with the crank and still same result. Bought a new cassette and whoop running as smooth as a baby's but.

 

The irony is I used the old drive train for like 4 months, the chain completly molded with the drivetrain.

[rudi-h]

I'd replace the chain first. Take it for a short ride and run through all the gears. If the chain "jumps" replace the casette there and then, if not, leave it.

 

Bike shops tend to "urge" you to replace stuff way too often!

[AndreZA]

I've never broken a chain in 18 years of riding and racing. No one can tell you how long a chain will or should last.

 

[Johan Bornman]

A worn chain does not break easier than a new chain, since the wear occurs in an area where strength is not an issue. Chains break by the sideplate popping off the pin. The pin and sideplate don't move against each other and thus no wear occurs there.

 

Replace your chain when it reaches the wear limit as shown in Mampara's excellent drawing.

 

You cannot judge a cassette's usefull life by inspection. If a new chain works on the old cassette, it is not worn. There is no merit in replacing a cassette before it is worn.

 

A worn chain does not affect shifting.

 

A worn chainring is the primary cause of chainsuck, but it is exasperated by an elongated chain and dirt.

[iRob]

Hahahahaha, I've been to Shimano's guys in Joburg in person and it was an eye opener to say the least. Needless to say it seems my LBS mechanics are not too clued up on what worn cassettes look/feel like. I was told my gears were slipping with a new chain due to the cassette being worn (700km, visible burrs present). So I replaced it with a spankingly new one; same issue. New chain and cassette... So I (me, not the mechanics) rode the bike and told them its the fron chain ring (~ 1500km on it) and tada. Good as new.

 

Took the cassette to Shimano in Jozi prior to the Sabie Experience and they reckon it'd last. Not ONE issue with shifting, come mud (my DT was COMPLETELY cover as only Sabie nows how to) or water or clay or sand or anything.

 

Funny enough after day 2 of 4 when I was planning to replace the cassette and chain, ALL the burrs on the cassette had been ground off by the mud and the gear changes were still clean and perfect.

 

Worn cassette.... Throw in some mud and let it grind the crap away. Chain has just reached 50% wear (short life due to Sabie mud and so on,) but it is still going strong.

 

I've also been told that using a a dremmel on the burrs (ONLY, I repeat, ONLY the burrs) will help an XTR cassette reach over 10000km. Straight out of the horses' mouth (The oke is not a horse though, and if he does it, I'll take his word for it and do it myself.) If you try it, just don't change the cassette profile. That WILL efffff your gears changes up...

[covie]

Johan I know your the expert but a worn chain cuases the rear cassette to misform and that does affect gears as the chain will start jumping on the cogs when any form of stress is applied.

 

Or am i missing something.

[Sharkie 2]

Get yourself a chain checker if it is worn to .75 on the tool replace the chain only, if it is worn more than .75 and maybe even 1.0 then in alot of the cases you need to replace the cassette and the middle blade. If you change your chain on .75 wear you can normally put on 3 new chains before the cassette and the chain rings need replacement

[The Drongo]

Sharkie 2 and Mampara have got it spot on.

 

(and Mampara appears to have been around the block a bit, as we can see, he works in inches)

 

.75 wear, replace chain.

1.0 wear you will probably have to replace your drivetrain, ie. everything.

 

There will always be those who disagree with the manufacturers specifications.

 

I side with Johan that a chain at 1.0 wear does not affect gear change so long as the chain, cluster and chainrings have worn together.

 

You can bust a chain new out the box through poor shifting technique, or running the wrong chain length i.r.t your drivetrain.

You can also cause damage to the chain if it is wrestled out of a bad jamb, between cluster and frame/spokes or frame and front inner chainring - the damage will only reveal when your chain goes 'ping'.

 

If you want your drivetrain to outlast chains, one method is to run 2-3 chains on a rotational basis (3 chains way cheaper than a new drivetrain)

Run chain 1 for couple 100k's remove, clean, oil and stash. Fit new and do the same, etc, until you are back to chain 1. Replace any or all at .75 wear.

Keep your chain well clean. Run dry lube for dry conditions and wet lube for wet conditions.

Your drivetrain will last for a long time, maybe even as long as Mampara.

 

If you want to see how long some setups last, read Around Africa on My Bicycle, by Riaan Manser. And that was all OEM ***.

[MissionMan]

Hahahahaha, I've been to Shimano's guys in Joburg in person and it was an eye opener to say the least. Needless to say it seems my LBS mechanics are not too clued up on what worn cassettes look/feel like. I was told my gears were slipping with a new chain due to the cassette being worn (700km, visible burrs present). So I replaced it with a spankingly new one; same issue. New chain and cassette... So I (me, not the mechanics) rode the bike and told them its the fron chain ring (~ 1500km on it) and tada. Good as new.

 

Took the cassette to Shimano in Jozi prior to the Sabie Experience and they reckon it'd last. Not ONE issue with shifting, come mud (my DT was COMPLETELY cover as only Sabie nows how to) or water or clay or sand or anything.

 

Funny enough after day 2 of 4 when I was planning to replace the cassette and chain, ALL the burrs on the cassette had been ground off by the mud and the gear changes were still clean and perfect.

 

Worn cassette.... Throw in some mud and let it grind the crap away. Chain has just reached 50% wear (short life due to Sabie mud and so on,) but it is still going strong.

 

I've also been told that using a a dremmel on the burrs (ONLY, I repeat, ONLY the burrs) will help an XTR cassette reach over 10000km. Straight out of the horses' mouth (The oke is not a horse though, and if he does it, I'll take his word for it and do it myself.) If you try it, just don't change the cassette profile. That WILL efffff your gears changes up...

 

dremmel? burs?

[brotherdarryl]

Thanks guys for the info. Ill be heading to the LBS to buy a new chain first...