Chainrings - inside out and double singles
Hi all and thanks to all for lots of help just from reading posts. This is my first time posting a Question.
I just got a Surly dingle cog (double fixed cog, 17/21) which I want to mate with 2 chainrings (38/42). Question: Since almost any 42 will have been designed to be mounted inside will it matter which way it faces? Can I use either singlespeed chainrings on either or both sides? And, if I am going to use a 9 speed chain as Surly suggests, I really have to still really worry about chainline?
Thanks in advance.