Tuesday, April 22, 2008

yea, yea, I know, an ounce of prevention.............

Ya'll not living in glass houses may particularly enjoy this.

Once again, I have a seatpost stuck in a steel frame. From the late 80s and my Bridgestone, I've had problems with the prevention part.

This time, I searched out a MORE thread from the last time this happened to my IF, in 2005, where Nick offered this advice:
" Take out the bottom bracket, turn the bike upside down, pour bunches of ammonia (yes, ammonia) into the seat tube and let sit overnight. It should pop right out in the morning. I've done this several times."

This advice was seconded by RickyD, referring to the late great Sheldon Brown. The great one says:
"Aluminum seatposts frequently become stuck by corrosion also, and penetrating oil is almost useless against aluminum oxide. Fortunately, aluminum oxide can be dissolved like magic by using ammonia"

I removed the saddle and poured about 1/3 bottle of ammonia down into the post and into the seattube. I don't have a weep hole on the bottom of my BB shell, and the shell only has a tiny opening to the seattube. The BB was still in the frame. So, the ammonia sat on the BB and backed up all the way into the seatpost and seattube. I also sponged lots of ammonia around the interface of the post and outside the frame. I let this sit overnight and waited for the magic to happen.

Put the saddle back on the next day and began twisting and wrestling with no luck. No movement at all. No magic. OK then, what now? Back to the WD-40 and penetrating oil, which have worked for me in the past even though they shouldn't have.

Repeated the same 8-hour soaking routines, first with WD-40, and then with penetrating oil. No movement, no magic again. Jody was helping me by this time, and looked for a way to get more leverage. We came up with an extra handlebar clamped into the seatpost clamp as tight as we could get it (it buggered up the handlebar - no great loss).

Still no movement. Started thinking of ways to freeze the post to contract it, thought of dry ice, but the dry ice store 4 blocks away didn't open until morning. So we stuffed ice cubes into the post/seattube until we started seeing condensation on the outside of the post. Then quickly clamped the handlebar leverage device back into the post and started wrestling again.

FINALLY, movement. Enough movement to get a bit more lube into the interface, and then it worked it's way out.

So, what really worked?? The ammonia? WD-40/penetrating oil? The ice? Or, the leverage bar? I don't really know, but I know what Nick said "...keepin' it greasy so it'll go down easy... "

5 comments:

Chris said...

We have a Bridgestone with the same issue. The bike is only used to tow the kids' trailer around so it's not a big deal, but I'd sure like to 'unstuck' that seatpost. Looks like I need to try the WD-40 -> ammonia -> ice protocol!

Albert said...

The answer is all of the above. I've always found that heat and cold work best but I always have ammonia etc already saturating the area from previous attempts. A blast of co2 down the tube from tire infator can also help for cold - Big Air cans have alot of co2 and is very cold.

camps said...

I wondered how quickly the cold from CO2 would last? Long enough to get the leverage bar or saddle re-attached?

How about spraying the CO2 on the outside of the tube? Does that work

I guess dry ice packed inside the tube would give you the most time to work with.

pabiker said...

Next time (and there will probably be one) try to add some fertilizer to the ammonia mixture - some refer to this as the Oklahoma Federal Method.

Albert said...

You want the seatpost to be cold (so it needs to be inside the seatpost) so it shrinks and the seat tube to be hot so it expands. The problem I've had is 2inches of aluminum spacers fused to the steel steerer of my fork. And the process was soak with ammonia & penetrating oil etc, heat spacers a bit with torch, blast co2 in steerer, and bang with brass mallet. I'm always afraid too much heat will fry the headset grease. I like the fertilzer method.