I am replacing a shift cable on my Trek FX for the first time which has 9 speed ST shifters. I removed the cable and compared it to a cable for my road bike which has 10 speed STI shifters.

The Trek FX cable seems to be thicker and the wire end seems to be larger. I thought that I heard that all Shimano shifter cables were the same. Looks like this is not true?

What about the cable housing?