Park CC-3 Chain wear Indicator

[country joe]

on the instuctions it says the cc3 is used to check chain wear at 75% and 1% select the correct side,
Which would it be for a road bike 75% or 1%.
Thanks CJ.

 

[andy_wrx]

The theory is that when the 0.75% side fits into your chain, your chain is getting worn and you should think about replacing it sooner rather than later.

And then when the 1% side fits, your chain is now warn and you need to replace it.

The idea is that if a chain is more than 1% worn it will be wearing your cassette and chainrings, so if you fit a new chain it'll slip and rather than just replacing the chain you'll have to replace the cassette too.
If you replace the chain when it's less than 1% worn, you'll be able to just replace the chain and the cassette will be OK with a new chain. Eventually you'll need a cassette, but it'll be after 5 or so chains.

The other approach is to not worry about it too much, allow chain and cassette to wear together well beyond 1% until they're absolutely knackered, then replace both of them.

The proponents of this argument reckon that it will be cheaper to do this than replace the chain several times - which approach you take is up to you.

It will depend on how frequently you get to the 1% chainwear, which will depend on your mileage, whether you ride in wet&gritty conditions, how often you clean the chain, etc, etc.

For myself, I swap wheels between bikes, so I can't have chains & cassettes in different states of worn-out-ness, so I replace chains at 1%

 

[Steve Austin]

If you replace chains at 77, you can get at least 5 chains to one cassette, before the ccassette starts to shift funny.

Even then you can then cycle 'sic' through the used chains on the rapidly wearing cassette and get more mileage out of it.

I also move cassettes from bike to bike, as certain bikes need better shifting imo. ie My commuter only needs old equipment as it gets used less and the shifting isn't that importnat

 

[Mr Pig]

The other approach is to allow chain and cassette to wear together until they're knackered, then replace both of them.

By that stage you'll actually need to replace the chainrings too. I guess it depends on the cost of the cassette and rings you're using but on lower end stuff like mine you're definitely cheaper wearing out the lot and then replacing it.

 

[girofan]

If you have costly gear made by Campagnolo or Shimano, Record or Dura Ace, it's best to change the chain immediately it shows wear. Don't replace with another Campag or Shimano buy a KMC or a Wippermann as they are more expensive but are of much better quality.