Worn chain after 500km (terrain, gravel, dusty, some roads also)

[maikechi]

Hello,

I have this problem with a chain on my bicycle. I am thinking what might be the case that my chain is worn after just about 500km (I mean 0,75% worn - not 1%). I think it might be terrain as I ride on forest offroads, sometimes also on gravel, sometimes on tarmac (roads) and also that I am 112kg heavy (I am quite tall - 201cm ) So what do you think? Are these the reasons why my chain does not last as long as 1 000 km or so ?

Here is my style of riding :
I do about 100km or more rides every second or 3rd day. Average climbing is 900m and I do change gears when climbing to the smallest one (I dont stand up on the bike since once my foot slipped from peddals because of chain )

So please, let me know if you can give me some advice, tips or just some ideas! I will be really healfull as I didnt find much about this on the other sites!

PS : I use SHIMANO GI 51 chain and I have an 8 speed!

 

[I like Skol]

Not sure I quite understand what you are saying here.

Your chain is showing 0.75% wear after around 500km?
You cover around 300km a week so are fitting a new chain every two weeks?

 

[Foghat]

500km is extremely low. How are you measuring chain wear? Are you sure the chain is actually worn that much?

Some chain wear indicators report new unused chains as 0.75% worn, due to the tools' design and the way they measure, so their calibration needs to be understood and taken into account when using them to monitor chain wear. Others use better designs and measuring methods.

Optimum designs for such tools, and the idiosyncrasies of non-optimum designs, are discussed here for instance:
pardo.net/bike/pic/fail-004/000.html

 

[Ajax Bay]

When you put the power down (standing up), does the chain skip (ie jump a tooth on the rear sprocket)? If not then the chain and cassette are happy and you can carry on riding. If it does skip then you need to change both chain and cassette.

I have this problem with a chain on my bicycle. I am thinking what might be the case that my chain is worn

You have shared no symptom which leads you to "think" that your chain is worn. After only 500km it's most unlikely. The effect of 'wear' on a chain is elongation, which as others have said, you can measure. Best way is with a 12 inch rule, to corresponding pin edges.
Did you replace the chain yourself? Your OP suggests the chain was new only a fortnight ago. Joining a Shimano chain is harder than using a quicklink, and less assured.

 

[maikechi]

Thank you guys for your answers!

500km is extremely low. How are you measuring chain wear? Are you sure the chain is actually worn that much?

Some chain wear indicators report new unused chains as 0.75% worn, due to the tools' design and the way they measure, so their calibration needs to be understood and taken into account when using them to monitor chain wear. Others use better designs and measuring methods.

Optimum designs for such tools, and the idiosyncrasies of non-optimum designs, are discussed here for instance:
pardo.net/bike/pic/fail-004/000.html

I have a tool for measuring the chain from CYCLO

 

[maikechi]

When you put the power down (standing up), does the chain skip (ie jump a tooth on the rear sprocket)? If not then the chain and cassette are happy and you can carry on riding. If it does skip then you need to change both chain and cassette.

You have shared no symptom which leads you to "think" that your chain is worn. After only 500km it's most unlikely. The effect of 'wear' on a chain is elongation, which as others have said, you can measure. Best way is with a 12 inch rule, to corresponding pin edges.
Did you replace the chain yourself? Your OP suggests the chain was new only a fortnight ago. Joining a Shimano chain is harder than using a quicklink, and less assured.

To be honest there are no symptoms yet. That is why I am little bit confused. I am changing gears fine, chain is also not slipping from the cog wheels So this was the reason why I asked here what might be the case as the "tool" is showing almost 0,75 already

 

[Ajax Bay]

Most likely reason is that the tool is a (vernacular) 'tool'. Measure 10 inch links along the top stretch under gentle tension carefully to check the percentage elongation, which I suspect (after 500km) will be <0.2%. Personally I use a millimetric scale and divide by 254.

 

[Foghat]

I have a tool for measuring the chain from CYCLO

That looks like it measures by pushing the rollers apart, and so overestimates chain wear by including the roller wear in the measurement.

If you prefer not to use the measure-with-ruler option, a more useful tool than your Cyclo will be one which pushes the rollers in the same direction when measuring, such as Shimano's TL-CN42, or the Pedros tool.

 

[andrew_s]

Alternatively, if you've got a digital caliper*, you can set it to inches, measure the gap between two adjacent rollers, zero the caliper, then wind it out to a little short of 5.5", and measure between rollers again. Any excess over 5" is pin wear (0.05" = 1%)

* on last Monday's "Middle of Lidl" so probably still available; £10, iirc.