I have the Park CC3 chain wear indicator. It says use either the 0.75% or 1% side to determine if your chain is worn. Anyone know what a shimano 9 speed chain should be before replacing ?
Blacky,
Regardless of brand, Shimano, Campy, Sram, etc., 0.75% would be recommended and 1% would be the max allowable to prevent excessive drive train wear. The more wear on the chain, the more wear the chainrings and the cogs are subjected to. Ultimately, this excessive wear will lead to poor shifting and the chain trying to jump cogs when under load (hard pedalling). You are free to choose when to replace your own chain.
You can save a little money now by not replacing the chain because it seems to be working fine even though the chain checker says it is worn and should be replaced. Then pay a “little more” (ha ha) later when you have to replace the cassette and or chainrings in addition to the chain to get the shifting performance and lose the chain skips/jumps to get the drive train performance you expect you should have.
At least you are trying to learn what to do and when to do it. That is commendable.
I hope this helps.
Oops. Wrong Chain Wear. Sorry. Carry on.