De-rusting Bike Seat-Post

I've acquired a bike that unfortunately has a seat post that is rusted
in place. It's not quite high enough for me as is, and I've run out of
solutions to the problem. The bike shops I've been to suggested that I
spray a de-rusting agent around the seat post, also removing the
bottom bracket and spraying from the bottom up, and also to remove the
bolt holding it up so that my gravitational potential energy may force
it loose while riding. This, over the course of 6 months or so, has
not proven effective. The shop suggested that they could hack the seat
post off, then attempt to hack the post itself from the inside,
however this could potentially ruin the bike entirely. I was hoping
that it would not come to this, so I was wondering if anyone had this
problem before and could shed some light on some possible solutions.

On Mar 2, 11:40*am, Veganeric wrote:
I've acquired a bike that unfortunately has a seat post that is rusted
in place. It's not quite high enough for me as is, and I've run out of
solutions to the problem. The bike shops I've been to suggested that I
spray a de-rusting agent around the seat post, also removing the
bottom bracket and spraying from the bottom up, and also to remove the
bolt holding it up so that my gravitational potential energy may force
it loose while riding. This, over the course of 6 months or so, has
not proven effective. The shop suggested that they could hack the seat
post off, then attempt to hack the post itself from the inside,
however this could potentially ruin the bike entirely. I was hoping
that it would not come to this, so I was wondering if anyone had this
problem before and could shed some light on some possible solutions.

I cut one out of an aluminum frame last year. I took my time and it
wasn't too hard. The post was alloy. Don't cut the post flush with the
top of the seat tube. If you're lucky, the post won't be way long
(mine was a mtn bike post in a C-Dale touring frame). A roadbike
seatpost will be shorter, and if it is near the minimum mark you'll
only have to score 5 inches or so and you'll be able to easily keep
tabs on whether you're winging the inside of the tube with frequent
inspections with a flashlight. You might have to make a few cuts. You
don't have to go all the way through to the tube because eventually
you will be able to peel a section of the post down and free it. Get
a fresh hacksaw blade and one of those "tight fit" handles for it.
Just check your work frequently to see that you are not cutting too
far.

Good luck. The work is slow, but not hard.

Cheers,

MD

Veganeric wrote:
I've acquired a bike that unfortunately has a seat post that is rusted
in place. It's not quite high enough for me as is, and I've run out of
solutions to the problem. The bike shops I've been to suggested that I
spray a de-rusting agent around the seat post, also removing the
bottom bracket and spraying from the bottom up, and also to remove the
bolt holding it up so that my gravitational potential energy may force
it loose while riding. This, over the course of 6 months or so, has
not proven effective. The shop suggested that they could hack the seat
post off, then attempt to hack the post itself from the inside,
however this could potentially ruin the bike entirely. I was hoping
that it would not come to this, so I was wondering if anyone had this
problem before and could shed some light on some possible solutions.

If you admit defeat in mechanical/chemical attempts, just
send it he
http://www.yellowjersey.org/goodn.html

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Mar 2, 11:40*am, Veganeric wrote:
I've acquired a bike that unfortunately has a seat post that is rusted
in place. It's not quite high enough for me as is, and I've run out of
solutions to the problem. The bike shops I've been to suggested that I
spray a de-rusting agent around the seat post, also removing the
bottom bracket and spraying from the bottom up, and also to remove the
bolt holding it up so that my gravitational potential energy may force
it loose while riding. This, over the course of 6 months or so, has
not proven effective. The shop suggested that they could hack the seat
post off, then attempt to hack the post itself from the inside,
however this could potentially ruin the bike entirely. I was hoping
that it would not come to this, so I was wondering if anyone had this
problem before and could shed some light on some possible solutions.

What material is the seatpost and what material is the frame? Doesn't
make a difference in the "cut 'n' peel" approach already suggested,
but knowing might prompt some alternate suggestions.

What are you using as a penetrating oil? IME lots of people recommend
WD-40 which I've found to be marginally more useful than tap water. I
like PB Blaster, Kroil, and Wuerth Rost Off, although I'm sure there
are others that work well.

Hopefully your seatpost does not look like the one in my old Trek,
otherwise you'll need several hacksaw blades... the thing could be
used as an anchor, but it still holds my seat away from the frame
acceptably so I haven't been motivated to replace it. Seriously, I
think it's something like 3/16" if not thicker aluminum. (and yes, it
is well greased.)

nate

How much too low?
Not all seats are equal in height above the mounting rails.
Try a taller seat. Seats with excess padding or springs (or both) are
usually taller.

I have had to saw out seat posts before. Days & weeks of soaking with
penetrating oil don't always work.

I've never had any luck with heat.

The last one was a bugger. I removed the bb, cut the top of the seat
post off, inserted a long threaded rod, added washers and a nut to the
bottom of the threaded rod thru the bb shell. Pull up. I used a
large socket (1 1/16") to allow the seat post to slide up inside and
provide a pulling point against the top of the frame, with washers and
a nut on the top. Lots of obstacles to that process like curved in
seat tube at the bottom, water bottle mounts sticking in too far,
curved top of seat lug, etc. but It worked with lots of effort but
minimal damage to the frame.

Veganeric wrote:
I've acquired a bike that unfortunately has a seat post that is rusted
in place. It's not quite high enough for me as is, and I've run out of
solutions to the problem. The bike shops I've been to suggested that I
spray a de-rusting agent around the seat post, also removing the
bottom bracket and spraying from the bottom up, and also to remove the
bolt holding it up so that my gravitational potential energy may force
it loose while riding. This, over the course of 6 months or so, has
not proven effective. The shop suggested that they could hack the seat
post off, then attempt to hack the post itself from the inside,
however this could potentially ruin the bike entirely. I was hoping
that it would not come to this, so I was wondering if anyone had this
problem before and could shed some light on some possible solutions.

Read this and apply: http://sheldonbrown.com/stuck-seatposts.html.

--
Tom Sherman - 42.435731,-83.985007

Rick wrote:
How much too low?
Not all seats are equal in height above the mounting rails.
Try a taller seat. Seats with excess padding or springs (or both) are
usually taller.

I have had to saw out seat posts before. Days & weeks of soaking with
penetrating oil don't always work.

I've never had any luck with heat.

The last one was a bugger. I removed the bb, cut the top of the seat
post off, inserted a long threaded rod, added washers and a nut to the
bottom of the threaded rod thru the bb shell. Pull up. I used a
large socket (1 1/16") to allow the seat post to slide up inside and
provide a pulling point against the top of the frame, with washers and
a nut on the top. Lots of obstacles to that process like curved in
seat tube at the bottom, water bottle mounts sticking in too far,
curved top of seat lug, etc. but It worked with lots of effort but
minimal damage to the frame.


"I've never had any luck with heat"

http://www.wolframalpha.com/input/?i...point+aluminum


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Mar 2, 11:40*am, Veganeric wrote:
I've acquired a bike that unfortunately has a seat post that is rusted
in place.

Like I told Ray:
(I hope yours is alum post in a steel frame.)

On Mar 2, 10:30 pm, Ryan Cousineau wrote:
I have a nice frame (steel) with a fairly nice (aluminum) seatpost stuck
in it.

Before I resort to cutting it up and pulling it out, I'd like to try
saving the post. So far heat (tried by someone else) didn't work, a few
days of liquid wrench and banging on it didn't work, either.

Ray,

I've loosed several very stuck aluminum seatposts in steel frames.
Here's a few thoughts:
1. COLD is GOOD. The alum contracts greater than the steel when
cold. I have waited till a cold New England winter day to free a
few. I take them outside to cool down, then bring them in, Turn the
bike upside down and put the seat post in a bench vice. Use the
leverage of the bike, twisting and turning the frame, to free the seat
post. It can be a two person job; take care to not over torque (I
worry about damaging the frame). The whole thing heats up with
friction. When it gets hot, I bring it out to cool down, and then
bring it in and start again.
2. AMONIA is GOOD. The culprit might be aluminum oxide; amonia
disolves it. It's fast acting. So, if it is going to do any good, it's
very quick -- no need to wait for it to soak over night.
3. It's hard to get liquid into the seat tube/ seat post area.
Remove any water bottle cage bolts, and try to pour some in there.
Removing the BB, gives other possibilities.
4. It might be just luck, but I like Krell (I hear it's alot like
transmission fluid) as a lubricant for freeing stuck seat posts.

Good luck. Keep us posted (no pun intended).
Larry

On Mar 2, 11:18*pm, LF wrote:
On Mar 2, 11:40*am, Veganeric wrote:

I've acquired a bike that unfortunately has a seat post that is rusted
in place.

Like I told Ray:
(I hope yours is alum post in a steel frame.)

On Mar 2, 10:30 pm, Ryan Cousineau wrote:

I have a nice frame (steel) with a fairly nice (aluminum) seatpost stuck
in it.
Before I resort to cutting it up and pulling it out, I'd like to try
saving the post. So far heat (tried by someone else) didn't work, a few
days of liquid wrench and banging on it didn't work, either.
Ray,

I've loosed several very stuck aluminum seatposts in steel frames.
Here's a few thoughts:
1. *COLD is GOOD. *The alum contracts greater than the steel when
cold. *I have waited till a cold New England winter day to free a
few. *I take them outside to cool down, then bring them in, Turn the
bike upside down and put the seat post in a bench vice. *Use the
leverage of the bike, twisting and turning the frame, to free the seat
post. It can be a two person job; take care to not over torque (I
worry about damaging the frame). *The whole thing heats up with
friction. When it gets hot, I bring it out to cool down, and then
bring it in and start again.
2. *AMONIA is GOOD. *The culprit might be aluminum oxide; amonia
disolves it. It's fast acting. So, if it is going to do any good, it's
very quick -- no need to wait for it to soak over night.
3. *It's hard to get liquid into the seat tube/ seat post area.
Remove any water bottle cage bolts, and try to pour some in there.
Removing the BB, gives other possibilities.
4. It might be just luck, but I like Krell (I hear it's alot like
transmission fluid) as a lubricant for freeing stuck seat posts.

Good luck. Keep us posted (no pun intended).
Larry

Here's a possible solution from 1995:


Tom Noll
View profile
More options Sep 14 1995, 2:00 am
Newsgroups: rec.bicycles.tech
From: Tom Noll
Date: 1995/09/14
Subject: Stuck Seat Post
Reply to author | Forward | Print | Individual message | Show original
| Report this message | Find messages by this author
Here's how I freed my seatpost after I tried everything else.

I went to the local grocery store and purchased about $6.00 worth of
dry
ice. I packed the dry ice around the extended seat post and let it
chill
for about 45 minutes. When the seatpost was sufficiently cool, I
twisted
the post with a large crescent wrench, and *presto* the seat post
released. It is important to chill the seatpost and not the seat tube
on
the frame.

Some caveats, this was on a custom mountain bike frame and there was
enough of the seatpost extended (several inches) to put a good chill
on.
I performed the operation on a summer day when the air temperature in
the
garage was above 90.

Lastly, I really had tried everything else; oil, penetrating
lubricant,
gentle heating, strong twisting. The frame builder suggested that I
return the frame and they would remove the seatpost with a torch,
check
the frame for trueness, and repaint it after severe heating. I was at
the end when I thought of the dry ice technique.

The dry ice worked for me, and I still ride the bike.

Tom Noll


give it a go?

Cheers,

MD

On 2 Mar, 18:07, N8N wrote:
On Mar 2, 11:40*am, Veganeric wrote:

I've acquired a bike that unfortunately has a seat post that is rusted
in place. It's not quite high enough for me as is, and I've run out of
solutions to the problem. The bike shops I've been to suggested that I
spray a de-rusting agent around the seat post, also removing the
bottom bracket and spraying from the bottom up, and also to remove the
bolt holding it up so that my gravitational potential energy may force
it loose while riding. This, over the course of 6 months or so, has
not proven effective. The shop suggested that they could hack the seat
post off, then attempt to hack the post itself from the inside,
however this could potentially ruin the bike entirely. I was hoping
that it would not come to this, so I was wondering if anyone had this
problem before and could shed some light on some possible solutions.

What material is the seatpost and what material is the frame? *Doesn't
make a difference in the "cut 'n' peel" approach already suggested,
but knowing might prompt some alternate suggestions.

What are you using as a penetrating oil? *IME lots of people recommend
WD-40 which I've found to be marginally more useful than tap water.

Plus Gas is the normal stuff here, but I hear dilute phosphric acid is
also useful, normally known as diet cola.

*I
like PB Blaster, Kroil, and Wuerth Rost Off, although I'm sure there
are others that work well.

Hopefully your seatpost does not look like the one in my old Trek,
otherwise you'll need several hacksaw blades... *the thing could be
used as an anchor, but it still holds my seat away from the frame
acceptably so I haven't been motivated to replace it. *Seriously, I
think it's something like 3/16" if not thicker aluminum. *(and yes, it
is well greased.)

nate