So, for strings it’s:
“Replace when it feels kind of sticky”
Or
“When the colour changes”
For bearings it’s:
“Clean whenever it makes a different sound than normal”
Or
“Clean whenever it’s noisy”
And then for axles its the good old
“'omg what the heck did you do to need to replace your axle”
…but I can’t find anything for response pads?
Like, at all?
So, please post in here mainly how YOU know you need to replace your response pads, and then you can also post how you know you need to replace your string or clean your bearing (…or replace your axle? No idea what would cause that to happen, but I feel like it would be obvious if it needed to be changed.)