Originally Posted by
Achristocat
I would like to know the thread / size of mounting holes to mount a rear rack,
Do you mean these?
They are M5 x .8 thread pitch. They come in various lengths depending on what you're mounting.
Every bike store has them. Every Home Depot has them.
They are the standard size for just about anything you'd mount anywhere on a bike (handlebar stuff not withstanding). Bottle cages, rear racks, mini pumps, fenders, etc