Those STX levers wont work very well with cantilevers.
They were NOT designed to ever be used with them
The 'adjustment' is just to trim some of the aggression out of the v-brake.
But hey, its the internet and anything goes these days!
Shimano's low profile cantilever brakes were not very good unless time and patience were used (and who had any of that aged 19??) giving the then new v-brake the chance to send everyone over the handlebars.
These and some Avids were / are possibly the only ever multi use levers. They adjust the cable pull.
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