Quote:Niner is 29mm AF hex, or a 3/4" UNF bolt head 1.1/8" but for the niner I made a nylon plug to fit at top to keep it straight and protect the fine threads. Obviously a 41mm leg has a smaller internal diameter. Easy to make and I'm happy to make up a set for the club if someone wants to be the keeper of the tools.
Just found this post Lee, measurements for mk1 tool are there but I dunno if they're useable measurements.