I can kick in one that i have not seen ref'd before:
clutch adjust at the back of the airhead trans has always been sketchy and frustrating and required multiple trials n' errors before i could get an adjustment that i really liked. The reason is the close quarters between the thin 13mm locknut and the even-thinner 10mm adjust screw-- trying to use normal thickness wrenches here was aways dodgy, usually requiring several attempts to get it right with no clutch slip or drag.
Being an old-skool cyclist as well as moto-rider i'd had an idea in the back of my mind for a while: a thin shop-grade Park bicycle hub 13mm cone wrench. Well recently i finally followed through:
$10 got me the shop-quality 13mm wrench, and i was even able to buy it locally (Bikes Plus), a double-yay!
This was the ticket-- this thing is thin enough to hold the locknut while any standard 10mm turns the adjust screw. Then a slight turn on the Park wrench and it's set. Perfect.
No more trial-and-error. The Park's even small enough to slip in place in the tool roll or stow in the tray or whereever.
It's the best $10 i've spent recently!