I have the Park chain wear indicator CC-3. How do I know which side is the correct one for my bike? Should I use the .75% or the 1% indicator for my hybrid? for my road bike? for my city bike?

I have a Park chain wear gauge as well...which is a lot easier then using a ruler for my aging eyes. General rule is...over .75% of chain stretch the chain is getting worn and you should replace it soon. 1.0% or more...the chain should be replaced.
HTH,
George

Chains are one of the least expensive components on your bike. Cassettes are about twice the price of chains. If you let your chain go for too long, it will also wear the cogs in your cassette that you use most often. Then, after you replace the chain, it will skip when you are riding in those cogs.

My recommendation is to replace your chain when it's somewhere between the .75% and 1% wear indicators. If your chain goes past 1% there is a very good chance that you will need a cassette replacement also. I think that running a chain for too long is a poor economy.

.75% is 7.5 times greater than .1%

Yeah it is, but they're talking about 1.0%

brilliant!

+1

The amount of wear on a chain is not uniform. So I change my chains when the whole chain is at least 0.75% and some of it is 1.0%.

I wasn't aware of that. I have always assumed that the wear would be pretty uniform so I've never checked a chain in more than one place. How much variation do you find to be typical?

i K.I.S. and replace the chain @ .75%. what are we talking: a coupla bucks?

ed rader

My Rohloff chain wear indicator says that the .75% side is for cassettes or freewheels with aluminum alloy cogs, the 1% indicator is for cassettes/freewheels with steel cogs. There just are not that many cassettes/freewheels with aluminum alloy cogs running around, so you're probably good with 1%.

Or you can just measure it with a ruler and go here: https://sheldonbrown.com/chains.html#...20Chain%20Wear

Section on chain wear at the bottom.

Thanks folks.

I measure my chains in more than one location. The most variation I've ever seen is 0.1. That's total variation which includes chain stretch, tool error and operator error ( my ability to read it accurately).
I must be conservative, I replace my chains when they exceed 0.6.

i err on the side of replacing my chains too soon too and i use the best sachs/sedisport/sram chains.

ed rader

+1, I use SRAM PC-68 whenever possible. IMHO the polished surface resists dirt resulting in a longer lasting chain. And they look cool.