tap & die set?
got to use one last night but not on a bike, but there's probably a use for it on a bike. drill out a broken bolt, then tap new threads for a new bolt. had to do that on our bath tub drain strainer screw. it corroded where it met the threaded hole so when I tried to remove it to clean the drain, it snapped. been putting it off but finally got down to it. lucky for me it uses a common 10/24 bolt