I finally saw the trick for a stuck seatpost at a race in Bend

I was helping a friend at a cyclocross event last fall when a rider came in with a steel frame and an aluminum post that wouldn't budge. An old mechanic from a local shop walked over, told us to flip the bike, and pour a small amount of ammonia down the seat tube, letting it sit for about ten minutes. He said the ammonia creeps into the corrosion without hurting the paint. It worked on the first try with a regular wrench. Has anyone else used this method on older bikes?

3 comments

3 Comments

rubyw832mo ago

Does the ammonia smell up the whole garage though?

karenm491mo ago

Sprayed some PB Blaster on a stuck post a few years back and let it sit overnight. Came back the next morning and it twisted out with barely any effort, though I did have to wipe up a little puddle of oil. That ammonia trick sounds way cleaner than my mess, might have to try it next time.

danieltaylor2mo ago

Ever hear of using cola for the same job? Read that somewhere once. The acid in it can eat at the rust. Ammonia sounds less messy though. That old mechanic trick is a good one to remember. Always nice when the simple fix works.