Quantcast

i need some help with a stuck seatpost

shifty S

Monkey
Jun 6, 2002
397
0
NWDC...Asheville
Hey peoples, I've got an Endless Lifetime frame and a Thompson seatpost, and they refuse to separate from each other. I have tried wrenches, pliers, breaker bars, and all manner of penetrating liquids, and nothing has worked. For the record, the frame is raw steel with no coating other than a thin layer of flash rust, and I'm thinking this is probably part of why it has become do difficult. They just wont budge. Help!
 
Apr 28, 2006
235
0
North White Plains, NY
It may be the aluminum/steel mix that's caused the seizing. But as for how to get the post out of there, sometimes using a blowtorch to heat up the seat tube will let you release the post. If it's a raw frame, doing that isn't a really big deal, if it's painted then you'll end up with a ruined paint job.
 

HAB

Chelsea from Seattle
Apr 28, 2007
11,581
2,009
Seattle
If all else fails, you can destroy the seatpost and get it out that way. You can:
-Drill a hole in the post, put some sort of a rod through it, and twist like crazy.
- Cut the head off the post, then carefully take a hacksaw blade and cut a vertical slit in the post without cutting the frame. Once the post has been slit, you can crush it to remove it from the frame.
 

r464

Turbo Monkey
Oct 17, 2006
2,604
4
Earth
From Sheldon Brown:
The torch technique is worse than useless when you are dealing with an aluminum seatpost stuck in a steel or titanium frame, because aluminum expands twice as much as steel, and 2 1/2 times as much as titanium for the same increase in temperature. In fact, the exact opposite technique will often do the trick for aluminum seatposts--cool the seatpost down as rapidly as possible. The contents of a CO2 tire inflation cartridge applied inside the seatpost can shrink it down just enough to do the trick.
 

shifty S

Monkey
Jun 6, 2002
397
0
NWDC...Asheville
ok well more background here: this bike is used almost exclusively as a street/park bike with a few dirt jumps mixed in, but i have recently decided i want to be able to get around without expensive ass gas, so i was just going to raise my seat and throw some gears on (instead of the 33/15 SS i've got on there now) and call it an all around bike...

so i'm thinking i might just get another bike, because i really really like the way this one is set up right now and i no longer see a reason to change that just because my knees hurt from time to time and i have to get out of the saddle constantly to go more than a mile.
 

46chief

Monkey
Jun 12, 2007
296
0
blow torch will chage the heat treatment properties of the steel or aluminium and possibly be a place where the frame will break.

Get a big pipe wrench and try to twist it before you cut the tube, it will grip the seat attatchment point well so don't cut it off. I a broke the frame torquing on it with the big pipe wrench. the seatpost will never come out, thank god it was just a ****ty road frame I was going to convert to fixed gear.
 

SUPASTAR2

Chimp
Sep 29, 2007
20
0
NYC
I had the same problem with my old bike,I used a vice grip & out it came after a lot of elbow grease & 3 seperate people trying.
 

trailblazer

Monkey
May 2, 2005
464
4
Jamaica
I saw a tech pour acid down the seat tube with the bike flipped. The alu post spilled out into a bucket like puke and the steel was clean and shinny.....all in a few minutes.
The hack saw method is the best.
I have had success with liquid wrench.
 

Serial Midget

Al Bundy
Jun 25, 2002
13,053
1,896
Fort of Rio Grande
I had to do the CO2 removal a few times on my old Univega - not that easy. I used at least a half dozen cartridges directly on the aluminum post and some warm lead packs that I borrowed from a physical therapist. First I emptied the cartridges as close to post as quickly as possible and then I wrapped the tube with the warm lead packs. I was able to save the seat post each time.
 

ultraNoob

Yoshinoya Destroyer
Jan 20, 2007
4,504
1
Hills of Paradise
Try Dry Ice. Wear Leather Gloves. Fill seat post with bits of dry ice. When sufficiently cold, twist. Worth a shot. If it doesn't work, you can always have some fun with water, dry ice, and an empty 2ltr. bottle
 

deadatbirth

Monkey
Aug 29, 2007
657
0
In a van down by the river
If all else fails, you can destroy the seatpost and get it out that way. You can:
-Drill a hole in the post, put some sort of a rod through it, and twist like crazy.
- Cut the head off the post, then carefully take a hacksaw blade and cut a vertical slit in the post without cutting the frame. Once the post has been slit, you can crush it to remove it from the frame.
these ideas work great...usually
 

jonKranked

Detective Dookie
Nov 10, 2005
86,049
24,576
media blackout
I had this problem too with a steel frame / al post. i wound up cutting a vertical slit in the post by hand to get it done. Get some beer and your bong (if applicable) because it takes a while.


And on the subject of CO2, if you get standard canned air for cleaning keyboards, which can be obtained at Office Max, etc. for a few bucks, hold it upside and it comes out basically as a liquid, evaporates really quickly, and is still extremely cold.
 

ManxMonkey

Chimp
Nov 21, 2006
11
1
Another method that sometimes works on an aluminium post in a steel frame is one of those pipe freezing kits that are typically used to form ice plugs in copper water pipes (to allow repairs or alterations without draining down the whole system).
Fit the foam jacket round the seatpost and inject the coolant as in the instructions for pipe freezing. You can try gently warming the seat tube with a hair dryer or hot air gun to obtain a little more temperature differential.
This assumes, of course, that you have at least 150mm or so of exposed seatpost to wrap the cooling jacket round.