In the build video for that Moccle bicycle, there's a blink-and-you'll-miss-it moment of a craftsman using this unusual tool:
That's a handheld pneumatic belt sander. The craftsman above is in Japan, where pneumatic tool manufacturer Shinano offers several versions, with belts as narrow as 10mm (a little over 3/8"). The angle of the sander arm can be adjusted.
They also make longer versions, for those hard-to-reach places…
…and wider-capacity versions. The two models below have belt widths of 20mm and 30mm, respectively (roughly 3/4" and 1 1/8").
'Stateside, you can pick up a 3/8" model, made by Central Pneumatic, at Harbor Freight for $28.
Join over 240,000 designers who stay up-to-date with the Core77 newsletter.
Test it out; it only takes a single click to unsubscribe