Joe We called these the Ultra 6 Chain. there were a few different kinds.Soon many of us discovered the emerging Sedisport Chain, hailed as an engineering marvel at the time because it used a manufacturing shortcut to punch the inner side plates and save extra parts. The Sedisport became the popular chain for the ultra as well as normaly-spaced.
If you need an authentic restoration, I have the official Ultra-6 chains. New ones are $15-$25 depending upon finish and plating,used ones are less but have plenty of life.
Mt Airy, Md
I have an early eighties Panasonic road bike which I am putting back
together, I have been told that these originally used a Suntour Winner or New Winner
series Ultra spaced freewheel. These were the ones that allowed a 6 speed
freewheel to be used on a 120mm spaced hub. I seem to remember that when the Ultra
spaced freewheels came out Suntour did have a different chain for these? Does
anyone know what is the correct chain for the Ultra type freewheel? Does it
require a special chain?