Chain replacement

[cubey]

So had the bike just over 14 months and 6000km, checked for chain wear and its worn to 0.75% bought replacement chain. As far as I can tell from the illustration you put the chain on with the lettering facing toward you as you look at the bike, am I right? Any other tips?

 

[Racing roadkill]

Yes that’s a directional chain. Put it on with the stamped letters facing outwards. Measure it against the old chain, and adjust it to the same length before you fit it.

 

[cubey]

Cheers

 

[Ajax Bay]

had the bike just over 14 months and 6000km, checked for chain wear and its worn to 0.75% bought replacement chain.

Given the chain has done that distance, I would be surprised if your drivetrain works satisfactorily as the cassette will have worn in parallel and when you try it with a new chain it will slip (so test it with the new chain on and put some power down in the road outside with the chain in one of the middle sprockets). Get on and buy a new cassette straight away so that if (or maybe later, when) that does happen, you have the cassette ready and will not miss any rides.

 

[cubey]

Never had any problems with gear changes always smooth with no hesitation or slipping, thanks for the advice will do that.

 

[Milkfloat]

Never had any problems with gear changes always smooth with no hesitation or slipping, thanks for the advice will do that.

It is not necessarily gear changes that @Ajax Bay was talking about it is more that the existing cassette may not mesh with a new chain as it could have been excessively worn by the old chain, hence it could skip/skate (depending on your terminology).

 

[raleighnut]

Given the chain has done that distance, I would be surprised if your drivetrain works satisfactorily as the cassette will have worn in parallel and when you try it with a new chain it will slip (so test it with the new chain on and put some power down in the road outside with the chain in one of the middle sprockets). Get on and buy a new cassette straight away so that if (or maybe later, when) that does happen, you have the cassette ready and will not miss any rides.

The other option is if the new chain does skip is refit the old chain and you'll get another year out of it. Then you change both.

 

[Ajax Bay]

@raleighnut speaks wisdom. Now that you've let the chain go beyond 0.75% enlongated, your best bet is to NOT change the chain and use the chain and cassette (which are 'matched' (as far as wear level is concerned)) till you start to experience 'slip'/skate (see @Milkfloat definition above). Then change both chain and cassette. Some may say that you'll wear your chainring(s) more but in the scheme of things this is not worth concern.

 

[raleighnut]

@raleighnut speaks wisdom. Now that you've let the chain go beyond 0.75% enlongated, your best bet is to NOT change the chain and use the chain and cassette (which are 'matched' (as far as wear level is concerned)) till you start to experience 'slip'/skate (see @Milkfloat definition above). Then change both chain and cassette. Some may say that you'll wear your chainring(s) more but in the scheme of things this is not worth concern.

Nah, I'm just a cyclist tight git.

 

[Racing roadkill]

Forget any nonsense you might hear about the cassette and chain needing to be changed at the same time, every time. It’s partly true, in that the chain and cassette wear in unison, and there’s a meshing that’s particular to a given chain and cassette. My experience ( depending on how many Joules you’ve put through the system, and the quality of the cassette and chain) is that you may get a bit of slip, with a new chain, on an old cassette, but it normally ‘re meshes’ after a few KiloJoules have gone through, and it’s not uncommon for a cassette to be perfectly serviceable, having had a couple of chains worth of use. Best practice is to change both cassette and chain together, but it’s not strictly necessary. I change cassettes and chains and Jockey wheels at the same time, but that’s just my personal preference.

 

[I like Skol]

Forget any nonsense you might hear about the cassette and chain needing to be changed at the same time, every time. It’s partly true, in that the chain and cassette wear in unison, and there’s a meshing that’s particular to a given chain and cassette. My experience ( depending on how many Joules you’ve put through the system, and the quality of the cassette and chain) is that you may get a bit of slip, with a new chain, on an old cassette, but it normally ‘re meshes’ after a few KiloJoules have gone through, and it’s not uncommon for a cassette to be perfectly serviceable, having had a couple of chains worth of use. Best practice is to change both cassette and chain together, but it’s not strictly necessary. I change cassettes and chains and Jockey wheels at the same time, but that’s just my personal preference.

I changed the last chain on my hybrid after 1500 miles as it was just at an indicated 0.75% using my normal wear checker. The new chain skipped occasionally for around 100-150 miles before it finally settled down. This was a pain and next time I either need to act sooner or just swap out the troublesome cassette. Life's too short to be running rough gear!

 

[andrew_s]

0.75% is in might slip, might not territory.

If you can avoid heavy stomp for the next few 100 km, it will settle down, but before then, you might get slip in an out of the saddle sprint from the lights, or on a steep hill in too high a gear.

 

[raleighnut]

0.75% is in might slip, might not territory.

If you can avoid heavy stomp for the next few 100 km, it will settle down, but before then, you might get slip in an out of the saddle sprint from the lights, or on a steep hill in too high a gear.

But never forget to keep the old part-worn chain, give it a good degrease in paraffin/white spirit/diesel oil then dry it off and immerse it in oil (I use an empty 1Kg flora tub) cos when a new chain won't run on a cassette the part-worn one will. DAMHIKT

Nah, I'm just a cyclist tight git.

 

[Ajax Bay]

Forget any nonsense you might hear about the cassette and chain needing to be changed at the same time, every time. It’s partly true, in that the chain and cassette wear in unison, and there’s a meshing that’s particular to a given chain and cassette. . . .it normally ‘re meshes’ after a few KiloJoules have gone through . . . . I change cassettes and chains and Jockey wheels at the same time, but that’s just my personal preference.

No nonsense propagated on this thread sfaics. If a rider let's their chain elongate beyond 0.75% (approx(!) and then changes the chain, if it doesn't slip: fine. But they'll get a lot fewer miles out of the second chain (because it'll be quickly and wearingly meshing (aka "settle down" in @andrew_s speak) with a cassette worn to match a 0.75% elongated chain). So from a mechanical and an economic point of view, it makes sense to just carry on with the 'old' chain till it starts slipping and then change both. This seems to me exactly the protocol you (rr) follow. But others have shown that replacing a chain once it's 0.5% elongated can be done twice on the same cassette (three chains per cassette life) and if a rider's cassette is an expensive one this is good or even best practice, depending on how a rider weighs the various factors.
Btw my maths suggests that a kilojoule is expended every few seconds (5 seconds at 200w) so I think maybe "after a few Mega Joules have gone through" (rather than kJ).

it will settle down, but before then, you might get slip in an out of the saddle sprint from the lights, or on a steep hill in too high a gear.

And who cares about the odd chain slip out of the saddle on a steep hill, eh?

 

[cubey]

Thanks for the informative advice fellas, all taken on board. Have ordered a new cassette. a Shimano 105 and chain, so will run this until it begins slipping or giving me problems.