Non-Flying Motorcycles

In the Kino’s Journey short story we’ve been reading in class, the following line appears as Hermes the talking motorcycle is introduced as a “Motorado”:


Translated: “Note: two-wheeled vehicle. Refers only to non-flying ones”.

The origin of the word appears to be German: “motorrad”, as in BMW Motorrad, makers of fine motorcycles. All the Japanese search engines I’ve checked turn up lots of links to Kino, followed by a few to generic motorcycle discussions.

So why does the author feel compelled to point out that Hermes can’t fly? I just spotted the exact same phrase while skimming through the first Kino novel, in every story. Where’s the ambiguity? If motorado isn’t in common use in Japanese outside of Kino and motorcycle fans, why stress the fact that Hermes is a non-flying two-wheeler, every time?

After eleven novels, two spinoff novels, an anime series, and two OVAs, isn’t someone who picks up a special-edition Kino book going to be pretty clear about at least the non-flying part? The novels are really short story collections, originally published individually in a magazine, so I can see the first half-dozen or so introducing unfamiliar katakana words like モトラド and パースエイダー, but doing it every time is either an editorial standard or a stylistic choice, and just calling it a “two-wheeled vehicle” is somehow insufficient.