For me, the short answer is that it depends.
It depends on how many bikes there are in total, how many categories I want to put them in, and how much knowledge about each bike I want to have in my system.
More of anything (or everything!) pushes me toward separate notes and some kind of MOC feature.
Smaller numbers of categories and items (and especially sparse information about each item) push me toward a single note.
How I organize that information then depends on how I am using it. If there is a lot of churn between categories, I might use a kanban board (with each card linked to an individual bike’s note and using the categories for the list headings) for my MOC. If the set is more stable, I might use a note with headings or an outline. In some cases, I might even use a note containing a table as my MOC.
It seems like this should be problematic, but since I have stopped trying to standardize every single thing (with lots of reminding myself that I’m building a second brain, not a franchise), I find it easier to work with my notes. I organize things in a way that is natural for whatever it is I am organizing, and I trust iteration and evolution to adjust that as necessary.