io uso sempre il calibro parktool.
occhio a misurare le catene nuove, non vorrei che bave/grassi diversi falsino la misura.
Infatti parktool non ha cambiato lo strumento di verifica usura con l arrivo del 12v
dal manuale parktool
[...]
Because a chain must have a small amount of play in the links to run
smoothly, the CC-2 will show a reading of .25% (or more) on new chains. This
does not mean that the chain is .25% worn. It only means there is .25% play
built into the links of the chain before it starts to wear. No matter what the
reading of a new chain, it should be replaced when the CC-2 shows a reading
of .75% (for 5, 6, 7, 8, 9-speed chains) or .50% (for 10, 11, 12-speed chains).
[...]