It takes 3 or more difference manuals, factory and Norton clubs and aftermarket plus the Norton Villagers to alert to the oversights and errors. The triplex chains are very tolerant of any possible potential miss-alignments just slapping primary together so real reason for the clutch shims is keeping it from rubbing inner case *after* inner case shimed square to crankcase face, sheeze. Only 3 things I can imagine allowed a new triplex to break, one, its was defective from the maker, two, it was so loose set it climbed to tops of sprocket teeth tension-ing beyond load limits or three, it was set too tight cold so thermal expansion jerked it apart. [checking main shaft straightness would be on my restless mind after triplex chain jerk apart] There are too many reports of very significant clutch wobble cases that did not break the triplex chain even if wearing slack in it faster, so might reconsider ones thoughts on what happened. I and others have used up all the good of triplex chains w/o fracture - just finding extra sloppy or pieces of links that didn't hurt anything - up to that point of bad.
