Try and somehow grind a slot into the bolt head with a dremel or something so you can get a flathead screwdriver in there.
Failing that, drill out the bolt really small, tap in a smaller screw, then araldite it in there, WD40 the fuck out of it, then unscrew that way...
@hazzus 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 and somehow grind a slot into the bolt head with a dremel or something so you can get a flathead screwdriver in there.
Failing that, drill out the bolt really small, tap in a smaller screw, then araldite it in there, WD40 the fuck out of it, then unscrew that way...