I don't think you can put disk brakes on that bike.
Cantilever brakes need a shorter cable pull than V brakes so the brake levers have two ways to hold the cable end.
Shown on page 3 here
http://si.shimano.com/pdfs/dm/DM-ST0001-05-ENG.pdf
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Genesis 49:16-17
"Well, well!" said Holmes, impatiently. "A good cyclist does not need a high road. The moor is intersected with paths and the moon is at the full."
Last edited by Darth Lefty; 09-17-17 at 11:19 PM.