Just thinking about buying a new front rotor in prep for the alps but wondering why hope are listed at both 200mm and 203mm and again at 180/183mm?

why such small increments?

I think they were competing standards at some point, possible to do with the IS and post mount changes.

I guess Hope offer both sizes so you can retro fit/replace either standard?

Obviously you’re not going to notice 3mm difference at the lever though.

So for PM forks (RS Pikes) then the 203 would be the way to go as this seems to marry up with the adapter offerings?

You can fit any size you like I guess as long as the mount and the disc match each other.