During the mid 1960’s Nobuo Ozaki, SunTour’s brilliant chief designer, was so prolific that he must have been speeding on a diet of pure Jolt Cola. Not content with producing the 1965 SunTour New Skitter, packed with innovations, he moves onto this - the 1967 SunTour Skitter.
The geometry is essentially the same, but the riveted flat steel plates have been replaced by a more rigid and three dimensional parallelogram.
It retains the two trademark features of SunTour’s own Skitter designs - it is low-normal (what Shimano now call ‘rapid-rise’) and it had only one spring, which, through devious design, provides both chain tension and operates the parallelogram.
So far, so sane - but now for the madness. The 1967 SunTour Skitter gets the natty adjustable pulley cage that was first seen on the 1964 SunTour Grand Prix. With a few twists of a handy wing-bolt the tension pulley can be moved to one of three positions giving a maximum capacity of 26, 30 or 34 teeth respectively. It’s almost as if SunTour thought that halfway through a ride you might decide to convert your bike from an out-and-out racer to a laid back tourer - and that you needed a wing-bolt because you were going to perform this conversion (surely involving at least the derailleur, chain, and freewheel and probably the chainset) even though you had not brought along a spanner.
A more likely explanation for the wing bolt is that it is an early ancestor of SunTour’s ‘Quick Cage’ - which allowed you to fit the chain into the derailleur without messing around with extracting a chain rivet. Here they are merely making it easy to remove and refit a pulley wheel with the same end in view.
A proud member of the pantheon of derailleurs with silly names.