Rehashed from my SUZ post:
The
Bahne Box aka the Longboard box / Fins Unlimited / Futures / American / US Surf / etc. is the
STANDARD for longboards, surfboards, the
major fin brands like
FCS and
Futures and most non-windsurfing SUP brands like
Bark,
SIC,
Sunova etc.
The
US Box is a windsurfing box which I believe was originally the Chinook Box and/or A Box and used by the majors; all of whom originated from windsurfing brands;
Starboard,
Naish,
Fanatic, etc. Why it's
US Box now and fins can be list as
US Box and/or A Box is some irrelevant windsurfing mystery.
The
Bahne Box is thinner and shallower vs the
US Box which is deeper and wider.
The
Bahne Box fin has a 9mm base width that is shallower and has a higher pin position.
The
US Box fin has a 9.2mm base width that is deeper with a tab and has a lower pin position.
Although
Standard Bahne Box fins fit into an
US Box, they fit too low in the box and are generally loose and wiggly around. You get lucky occasionally, but there are a few sure fire fins that always fit tight; the FCS IIs!
No reason ever to fit a
US Box fin into a
Bahne Box. For a proper fit, the base needs to be ground down and the pin relocated. Besides that, the G10 fins are heavy, overkill for SUP speeds, over priced and designed mostly off old windsurfing fins.
