Carbon post stuck in aluminum frame.

On Sat, 06 Aug 2005 00:48:40 GMT,
wrote:

Wayne Pein writes:

What is the mechanism for this and is there are way to get it out
and prevent future freeze ups?

I haven't heard of this before but it is probably the same as in any
kind of steertube. From the way you write this and that it is "stuck"
makes me visualize a quill stem.

The quill stem is dead! Dead! Dead!

http://www.sheldonbrown.com/brandt/stuck-stem.html
http://www.sheldonbrown.com/brandt/t...s-headset.html

Use quill stems on antique bicycles and only for display purposes.

I think he was talking about a *seat* post.
--
Typoes are a feature, not a bug.
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On Fri, 05 Aug 2005 20:06:05 GMT, Wayne Pein wrote:

What is the mechanism for this and is there are way to get it out and
prevent future freeze ups?

Water slung from the rear wheel may work into the interface through
the slot below the clamp. If corrosion forms inside the seat tube,
the post can be well and truly stuck even if it's carbon. In my
experience, aluminum frames are *much* more likely to have problems of
this type than steel, but aluminum is what you've got, so that's what
must be addressed.

Getting it out: Assuming that the seat tube is open to the BB shell,
turn the bike over, remove the BB and fill the seat tube with ammonia
solution through the BB shell. Leave it for a few days. the ammonia
will slowly eat the corrosion out of the tube, but if the corrosion is
extensive, this may take longer than earning the price of a Trek
Madone via panhandling in Harlem. Penetrating oils may attack the
carn=bon post, so that's inadvisable. Using a hair dryer to gently
heat the seat tube (NOT a heat gun; that could overheat the tube too
easily) may expand the tube enough to allow the post to be worked
free. It may be more effective to just leave the bike laying in
direct sun on a hot afternoon, though.

Others will have additional suggestions. As a last resort, the post
can be sawed off, split internally through tedious and careful use of
a hacksaw blade as a jab saw, and then extracted in one or more
pieces. On my aluminum-frame bikes, I use aluminum posts, and I pull
and clean the post at least once a year, reinstalling with enough
grease to keep water intrusion from being a problem.
--
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On Sat, 06 Aug 2005 15:19:52 GMT, Robin Hubert
wrote:

colnalu wrote:
wrote:

Wayne Pein wrote:


What is the mechanism for this and is there are way to get it out and
prevent future freeze ups?

http://www.sheldonbrown.com/brandt/stuck-stem.html


Sorry. I should have been more precise and said it is a seatpost. I'm
also posting for a friend. The seatpost is a Deda Black Magic and the
frame is a DeRosa Dual.

That doesn't make much difference, the problem is the same although
seatposts, when properly secured, do not pump water into the interface
and don't seize up. When and if you get it out, make sure the post is
well greased and the expander slot in the frame well plugged with
grease to prevent water intrusion. Since this is essentially a static
contact, it will not ingest water.

Jobst Brandt


I think it is very silly to advise the use of grease on a carbon seat
post. Higher clamping forces would be required as a result, which might
distort the post harmfully. See many previous debates on this topic
here on r.b.t.

I have to ask, does anyone have any proof that "higher clamping forces"
are required to keep a greased post in place?

Another solution is to remove the post every year, wiping it and the
inside of the seatpost clean. I am forced to do this every six months
on my Campag Record post and Colnago aluminium frame since the grit
build-up causes all those weird ticking sounds that I love to hate . .
.

The reason you're "forced" to do this is that, otherwise, you might face
a "frozen" stem or post.

/Robert p.s. on the subject of which end of the bike the OP was
referring to, I've never heard of a carbon quill stem on a threaded
fork, have you? :-/


Robin Hubert

Dear Jobst, Colanu, and Robin,

As has been mentioned . . .

Sorry, couldn't resist it.

Manufacturers generally warn against greasing carbon seat
posts--the grease is not good for the post:

http://groups.google.co.uk/group/rec...e=source&hl=en

It can attack the resins in the carbon fiber.

Carl Fogel

wrote:

Manufacturers generally warn against greasing carbon seat
posts--the grease is not good for the post:
There is a newly developed carbon paste (for mounting carbon seatposts in
carbon frames). According to TOUR, it reduces the needed torque by at least
30%. It's calles Danamic acrbon Paste.

www.vanbokhoven.de

Greetings, Derk

I'm sorry: Dynamic Carbon Paste

On Sat, 06 Aug 2005 21:15:41 +0200, Derk
wrote:

I'm sorry: Dynamic Carbon Paste

Dear Derk,

The assembly paste of DYNAMIC is a new development pointing
the way on the bicycle market and an indispensable
assistance when the assembling of high-quality carbon and
aluminum components. The assembly paste has to eat or stick
a strongly restraining effect without thereby. Thereby the
necessary starting torque of respective wedging is reduced
over up to 30%. The danger of overturning the clamping
screws is thus gebannt. Sensitive carbon surfaces are less
strongly loaded - with same protection against rotating -,
are not damaged those fibers. Crack noises are eliminated.
The assembly paste offers highest corrosion protection and
is extremely steady against splash-water. The area of
application is when the assembling of all conclusive
connections between carbon, aluminum and steel, with which
absolute protection against rotating and release as well as
against corrosion is necessary. Saddle bracket porch,
steering wheel handle, steering wheel crescent interior
bushes, pedals, cranks schraubgewinde resistance against
water: highly viscosity: very viscous (with 20°C)
coefficient of friction: very highly




http://www.vanbokhoven.de/firstframe.html



My translation is dubious [1], but I get the impression that
this stuff is supposed to be sticky, unlike grease, and is
supposed to resist corrosion, while grease can damage carbon
fiber.

If it is indeed sticky, but doesn't corrode or otherwise
glue things together, then it might well work wonders, just
as it claims, by reducing how much the seat clamp must be
tightened.

And it's red! Obviously, it will increase the seat post's
speed.

Thanks--I'd never heard of it.

Carl Fogel

[1] "The assembly paste of DYNAMIC is a new development
pointing the way on the bicycle market and an indispensable
assistance when the assembling of high-quality carbon and
aluminum components. The assembly paste has to eat or stick
a strongly restraining effect without thereby. Thereby the
necessary starting torque of respective wedging is reduced
over up to 30%. The danger of overturning the clamping
screws is thus gebannt. Sensitive carbon surfaces are less
strongly loaded - with same protection against rotating -,
are not damaged those fibers. Crack noises are eliminated.
The assembly paste offers highest corrosion protection and
is extremely steady against splash-water. The area of
application is when the assembling of all conclusive
connections between carbon, aluminum and steel, with which
absolute protection against rotating and release as well as
against corrosion is necessary. Saddle bracket porch,
steering wheel handle, steering wheel crescent interior
bushes, pedals, cranks schraubgewinde resistance against
water: highly viscosity: very viscous (with 20°C)
coefficient of friction: very highly"

http://babel.altavista.com/tr

for http://www.vanbokhoven.de/firstframe.html

wrote:

If it is indeed sticky, but doesn't corrode or otherwise
glue things together, then it might well work wonders,
It was tested by a technician of TOUR Magazin and he said that he could use
torques up to 50% less than prescribed by manufacturers. The Dynamic paste
contains small plastic/carbon? particles that are said to increase
resistance between the 2 frame and the part that has to be clamped.

And it's red! Obviously, it will increase the seat post's
speed.
That's certain! A pity you won't see it.......

Another job for your translator:

http://www.tour-magazin.de/to/tour_a...d=31&subnav=21

Greetings, Derk

wrote:
schraubgewinde
That means "thread"

Greetings, Derk

On Sat, 06 Aug 2005 22:41:05 +0200, Derk
wrote:

wrote:

If it is indeed sticky, but doesn't corrode or otherwise
glue things together, then it might well work wonders,
It was tested by a technician of TOUR Magazin and he said that he could use
torques up to 50% less than prescribed by manufacturers. The Dynamic paste
contains small plastic/carbon? particles that are said to increase
resistance between the 2 frame and the part that has to be clamped.

And it's red! Obviously, it will increase the seat post's
speed.
That's certain! A pity you won't see it.......

Another job for your translator:

http://www.tour-magazin.de/to/tour_a...d=31&subnav=21

Greetings, Derk

Dear Derk,

This sounds like the stuff works like grit rather than glue,
though there's probably a better word than "grit".

Presumably, hard pieces stick between tiny irregularities of
the post and tube to resist turning or moving up and down,
like two pieces of sandpaper.

The principle sounds like the opposite of anti-seize paste
that contains tiny pieces of soft metal that smear between
the two surfaces.

The Babel translator has a 150-word limit, but here's the
address again for anyone interested:

http://babel.altavista.com/translate.dyn

Carl Fogel

Hi Carl,

wrote:

This sounds like the stuff works like grit rather than glue,
though there's probably a better word than "grit".
Yes, the small particles that are added are sais to bind to the carbon and
thus the friction between the two materials is enhanced.
I heard from someone who used it, that it sounds like there's sand between
the two parts when you tighten the bolts.

Presumably, hard pieces stick between tiny irregularities of
the post and tube to resist turning or moving up and down,
like two pieces of sandpaper.
Yes,I think so.

The Babel translator has a 150-word limit, but here's the
address again for anyone interested:
I think they use the same translators that are used to make user manuals
that come with electronic equipment that is produced in Far Eastern
countries ;-)

Greetings from extremely wet Holland, Derk