I'm assuming that the seatpin is alloy? If it is then heating won't work, the alloy will expand much more than the steel frame. A method I've used successfully in the past is to immerse the seatpin and top of the seat tube in a bucket of crushed ice for half an hour or so, clamp it up nice and tight in a vice, wrap a rag soaked in boiling water around the seat tube (use gloves!) and twist immediately. If it doesn't move then repeat. If you can get some movement, no matter how small, you are winning and the pin will, eventually come out.
How are you going to machine it anyway? You'd need a lathe with a hell of a big swing! and if the rims aren't absolutely true to start with you'll lose too much thickness.
Search Options
Types to Display
LFGSS
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.
I'm assuming that the seatpin is alloy? If it is then heating won't work, the alloy will expand much more than the steel frame. A method I've used successfully in the past is to immerse the seatpin and top of the seat tube in a bucket of crushed ice for half an hour or so, clamp it up nice and tight in a vice, wrap a rag soaked in boiling water around the seat tube (use gloves!) and twist immediately. If it doesn't move then repeat. If you can get some movement, no matter how small, you are winning and the pin will, eventually come out.