Don, et al.
The first generation Sugino Maxy cranks had a stamped aluminum chainring swagged onto a cast aluminum crank arm. The chainring had 3 bolt holes to attach an inner chainring.
http://www.gitaneusa.com/
Gitane started shipping Sugino Maxy cranks on their Interclub models probably around late 1972 or early 1973. The Interclub was Gitane's amateur racing model with "racing" frame geometry and sewup tires.
I remember replacing several of these Sugino Maxy crankarms under warranty because the swage failed and the chainrings came loose. It took months to get replacement crankarms from Gitane.
Sugino, SR (Sakae Ringyo) and several other Japanese makers produced this style of cranksets. They started off as cheap cotterless aluminum replacements for cheap steel cottered cranksets...
The first versions were poorly designed and executed. There are only a few cast aluminum alloys with adequate strength plus enough malleability to be properly swagged.
I think that there were several possible explanations for these shortcomings. In those days there wasn't a strong sport cycling tradition in Japan. Keirin track racing is more akin to dog or horse racing than a participant sport: the big draw is the parimutuel betting. Add to that, the physical stature of the average Japanese person was probably 20% less than the average European or American.
In those days, most Japanese bikes and components were made to meet the specifications of the overseas importers. They were designed more for marketing than for technical reasons. It was several more years before the really innovative Japanese cycling products came about.
There were rumors of swage failure with the other Japanese brands too. It appeared that the Japanese makers used the same swage dimensions on the first aluminum cranks as those used on cheap steel cranks. In general, aluminum has 1/3 the strength of steel so the swagged material would need to be 2/3 larger!
While those first swagged aluminum cranks were a major improvement over cheap steel cottered cranks, as a result of my early experiences I've always considered them cheap and poorly designed.
Maybe I'm a techno-snob but good quality forged aluminum cranks like Stronglight model 49, TA Cyclotouriste or Nevar where only a few dollars more!
BTW, we never sold many Interclubs because for $50 bucks more you could get a Gitane Tour de France with a Reynolds 531 frame, Campy Tipo hubs and a forged Stronglight 93 or Sugino Mighty Competition crankset.
Chas. Colerich
Oakland, CA USA