Presented at the Milan Show in
November 1983, and marketed from March 1984 Aprilia was now moving forward to
the limit
in this category: more powerful and more beautiful than the ST 125 from which it
derives directly, the STX immediately became a bestseller.
The STX immediately presents itself as more mature and not only for
the presence of the windshield and front toe. The pearl white with red
and black inserts is certainly modern and the comfortable saddle
is now enhanced with the Aprilia logo on both sides. The oil tank is
immediately in front of the headstock and the plug is easily accessible,
being located just before the petrol cap.
The instrumentation is the same as with the ST. The
electric controls are now Italian (CEV) manufactured, although, in the
opinion of the writer, are perhaps a little less pleasant than the Magura
previously installed on the TS.
Engine
The ST's Hiro engine remains virtually unchanged. According to data
collected at the time, it gain in terms of power output is about 0.5hp or 18.48hp
at 8500rpm instead of 18.07hp
to 8250rpm. Not bad considering the limited interventions and the fact that
the mixer "eats" a little more 'power.
More radical, however, assistance where all transmission gear ratios have
been lengthened and decreased the secondary reduction ratio and in sixth, from 1:8.04 to 1:7.77; the maximum speed
however, due to
increased power and new gear ratios increased from 126.8 to 129.7 km / hour.