Presta valve core remover tool keychain
A tiny keychain tool that unscrews the removable core from a Presta valve on Stan's, Muc-Off or Peaty's tubeless valves so you can inject sealant or clear a clog trail-side. The head has a slot sized to the two flats of a standard valve core with 0.1 mm clearance, a 6 mm bore that centres over the valve stem, a knurled 10 mm shank and a 5 mm keyring hole. Print it upright in PETG at 100 percent infill and 0.1 mm layers so the slot faces are sharp; it takes far more torque than a core needs.
Bought core tools are strong but easy to lose, and a downloaded one may be cut for a different core. Ask SpeakCAD for the tool with the flat width you measure on your cores, preview it free in the browser, add a valve cap holder in the chat, then download the STL.
Create a Presta valve core tool 35 mm long with a 10 mm knurled shank, a head slot 3.3 mm wide and 5 mm deep for the core flats with 0.1 mm clearance, a 6 mm bore 4 mm deep centring on the valve stem and a 5 mm keyring hole.