Probably a pointless chain stretch question

[maxfox44]

Hi Guys

Been hammering my Giant Defy 0 as my commuter. It's done two winters and around 3000 miles from new.

I decided to buy a chain stretch tool as a friend said I'd probably already ruin the chain rings and cassette by never replacing the chain. The tool doesn't drop into the chain at 0.75 and I've even tried someone else's to double check.

Is this normal? I've seen other posts about changing chains at 750-1000 miles. I'm way over that.

Btw, no issues with the bike nor all the teeth look normal.

 

[maxfox44]

Less than. The tool doesn't even go into the chain

 

[andrew_s]

It would certainly be normal for a chain to be worn enough to require a new cassette at a change after 3000 miles, but chain wear can be very variable.
Flat roads and peaty soil would certainly give less wear than somewhere hilly with sandy or gritty soil (says I, making assumptions about what Lincoln is like).

You can double check with a ruler - if 12" of chain measures 12 1/8" when pulled taut, it's at the 1% stage (measure the 11.5" pin if the ruler doesn't go past 12").
[edit] On a new chain, chain pins are exactly 0.5" apart, so the distance between a pin and the pin 24 along is 12". On a worn chain, the pins are further apart, so the distance between pin 0 and pin 24 is more than 12".

Basically, if a chain is worn to 1%, the cassette will be worn enough that a new chain will skip on it, so you have to change the cassette too. You can carry on using the old chain and old cassette without problems for quite a long time, but the longer you leave it the more worn the chainrings get, and after a certain stage you'll have to change them too (they do look obviously worn by that point).

 

[ColinJ]

Do you keep the chain immaculately clean?

You are doing well if you can ride a bike 3,000 miles and through 2 winters without any significant wear and tear on the chain!

Do you have decent mudguards on the bike?

Another test ... put the chain on the big ring and see if you can pull it away from the teeth and expose them. A worn chain will be sloppy and easy to pull away. An unworn chain will not be and won't be!

 

[keithmac]

I've seen motorcycles with 3,000 miles on with knackered chain an sprockets and bikes on 20,000 miles still on the originals.

It all depends on how you look after it/ lube it and how often you do it imho.

Deffinitely a difference in quality and wear resistance between decent makes and chinese tat..

 

[maxfox44]

Thanks guys. I've got mudguards and do look after the cleaning and lube.

I've also tried the pulling the chain off the chain ring and it seems fine. In fact I did this before getting the checker tool.

 

[keithmac]

You can tell by the profile on the mainly used front chainring teeth what overall condition the drivetrain is in, hooked teeth means it's fubar but it would slip long before that.

 

[jay clock]

For the cost of a chain I change mine pretty often and cassette every third change

 

[ColinJ]

Thanks guys. I've got mudguards and do look after the cleaning and lube.

I've also tried the pulling the chain off the chain ring and it seems fine. In fact I did this before getting the checker tool.

It sounds like you are doing a good job of looking after it then!

 

[Blue Hills]

Interested reiver - which are these £5 chains?

 

[Salty seadog]

Riding style also has a lot to play here. If you stay in the saddle and spin instead of grind then you are putting a lot less strain on the chain. Mainly flat riding rather than hilly terain will also put less strain on the chain.

 

[maxfox44]

Thanks for all your replies. Most of my miles are flat country (but dirty) B roads. I also have a cadence sensor and try to spin at 80 revs, so I guess I'm easy on the chain. It's the original KMC chain. Looking at the replacement costs anyway.

 

[nickyboy]

Interested by this idea of hilly riding causing more chain "stretch". Chains don't stretch, they wear. My understanding is that it's the inner diameter of the bushings that increases due to wear with the chain pins.
So what are the main causes of wear? I guess that the force applied through the links is a minor one but the main one has to be the debris inside the contact points in the chain links
I use KMC chains and live in a very hilly area but try hard to keep chain and sprockets as clean as possible. I get about 2500 miles per chain average

 

[maxfox44]

On our group rides, the leader is forever warning everyone not to stand when climbing. Extreme issue, snapping the chain, chronic issue of extra chain wear.

 

[Slick]

On our group rides, the leader is forever warning everyone not to stand when climbing. Extreme issue, snapping the chain, chronic issue of extra chain wear.

That's going to stir a debate.