I got a factory chain/sprocket DID 525-112 package ordered off the microfische (Triumph genuine part A9618019). The chain came with a rivet link set (link, plate, x-rings). Of course, I got the Speedmaster 16 instead of a BA 17 or a newer Speedmaster 18.
Don't think you're going to find a DID 525-112 endless loop out of the box.
Not sure why the instructions about taking off the swingarm. I guess if you rivet the link before installing (I don't know who would, but maybe someone would) then you'd have to remove the swingarm.
