a simple trick to simplify setting up the sprint's front forks - for normal way up forks with screw in adjusters on top - older sprint owners know what I mean when I replace oil OR reset the adjusters to recommended spec I used to bugger abound with rulers or tape measures and it was a right sod of a job I discovered an easier way and its blindingly obvious (eventually) get one of these adjustable set squares - set it to the depth you want (145 mm).. insert into compressed fork stanchion with spring out - so it is sitting flush on the top and fill with oil until it just touches the ruler using a torch to illuminate (a head torch is great for this)....and of course the big advantage over a ruler is it can't accidentally drop down inside the tube to set the fork adjusters back to standard (10mm) set the square to 1cm, place across the top of the adjuster and measure down... adjust and check... etc couldn't be simpler really....
I use a stainless steel straw, pack of 4 for £1, drill hole same size as straw in a 50x50mm piece of clear plastic and set to height with a tie wrap; then put a piece of silicon tube on end of straw and suck the oil out with vacum brake bleeder.
that poor bike - what has it done to make you hate it so much... its a Triumph...TLC and pampering.... 8)