I noticed I have a box full of cassette cogs -- all Shimano 9-10 speed.
Right now I'm running a 12-23 that is way too burly for the more intense hill exercises here. I need relief before next weekend (a century) and a grannier cassette I ordered some time ago online still hasn't shown up yet. Is it possible for me to cobble together a 12-30 out my current cassette parts? Would it all fit together?