The 3-pin Sugino Maxy cranks I remember came on bikes that were entry-grade machines, such as the Batavus I got in '75. Prior to its arrival on the market, the bikes it usually came on were fitted with inexpensive steel cottered cranks.
I actually used a similar SR 3-in crank for a while on a fixie, and it was all right - but typically the big ring flexes a lot ...
Russ Fitzgerald
Greenwood SC
rfitzger@emeraldis.com
http://www.emeraldis.com/
http://www.anaburrous.com/