Originally Posted by
Aardwolf
Here's my compilation so far: [snip]
If the "5 mm hex" refers to the wrench, then that should be 4 mm. The bolt is M5, but the wrench is a 4. On the ones I owned anyway.
Maybe add Weyless ('70s) to the list, though they're rare nowadays. Very lightweight. I think they came in 27.0 but I can't swear to it...