Here's how I removed a totally corroded in seatpost on a Tri bike:

Starting with cutting the seat post off leaving enough materiel to grab in a bench vise, I started cutting a split in the post with a jab saw and finished the cut with a folding brush saw.



After an hour or so I finally broke through the aluminum at the bottom of the post. It was not only electrolytically welded to the inside of the seat tube but rusted solid (rust expands/grows making removal more difficult.

Word of caution... make sure that you're only cutting the aluminum and nut getting into the steel tubing. That's why I start at seat lug split in the rear. I can cut down ~25-30mm to get the deeper cut started.

I was finally able to remove the post by crushing it to break the bound to the seat tube. Reaming and honing afterward cleaned up the seat tube ID.

A simple glop of grease inside the seat tube and on the seatpost would have prevented this....

FLI (Friggen Lazy Idiots)

The grease trick works with stems too!


Addendum... While Centurion Ironman bikes came stock with them, who in their right mind would use a fluted seat post in a triathlon bike where water is going to get down into the seat tube??? I guess T-letes don't have to be very snart!


verktyg

Chas. The Impaler