try spanking a torx bit it there that's slightly too large?
or if the underside of the steerer tube isn't capped off could you get some needle nosed pliers on the outside of the bolt inside the steerer tube and undo it from the inside.
^This (the hammered torx) approach is sound.
@fredtc started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
try spanking a torx bit it there that's slightly too large?
or if the underside of the steerer tube isn't capped off could you get some needle nosed pliers on the outside of the bolt inside the steerer tube and undo it from the inside.