light metal

[Emanuel Berg]

Today there was a guy with a kid bike and the
saddle post was stuck in the pipe. He said it
was because the frame was of "lättmetal", which
is literally "light metal" but Google translate
gives "alloy". To me it looked like aluminium
but then again I haven't seen anything.
Is there anything known as "light metal" in the
bike frame world that I've missed?

And did it get stuck because of some issue
related to the material?

Anyway we were able to solve their problem by
first flushing with CRC 5-56/WD-40, then
putting a pipe inside the saddle post, then the
whole thing (the bike upside down) into a vice,
and then rotating the entire bike it came
loose easily.

So we got the saddle a bit higher and the dad
was very content and very impressed by the
whole operation for some reason. The daughter
tested the bike and said it was great, only the
saddle was too high!

:D

--
underground experts united
http://user.it.uu.se/~embe8573

[AMuzi]

problem:
http://www.preservationscience.com/materials/metals/PGC.html

amelioration (which is not actually a solution but very
effective):
http://www.antiseize.com/Anti-Seize-Compounds


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

[Frank Krygowski]

On 4/22/2018 11:19 AM, AMuzi wrote:
> On 4/22/2018 8:43 AM, Emanuel Berg wrote:
>> Today there was a guy with a kid bike and the
>> saddle post was stuck in the pipe. He said it

>> was because the frame was of "lättmetal", which

>> is literally "light metal" but Google translate
>> gives "alloy". To me it looked like aluminium
>> but then again I haven't seen anything.
>> Is there anything known as "light metal" in the
>> bike frame world that I've missed?

It almost certainly was an aluminum alloy. In English, the technical
definition of "alloy" is a combination of metals, or in some cases
including a bit of a non-metal like carbon. But in English bicycling
slang, "alloy" often refers to aluminum alloys.

A bit more detail: Pure aluminum isn't useful for bike parts or anything
else requiring strength. It's light, but quite soft and weak. But if you
add a couple percent copper, zinc, or other metals to aluminum, you can
get aluminum alloys whose strength to weight ratio is better than common
steels. That's what lots of bike components are made of.

Steel is an alloy of iron plus carbon and small amounts of other metals.
Titanium alloys exist and are occasionally used in some unusual bike
parts. Brass is a copper alloy, and I suppose you might find it in some
bicycle bells. But again, in the bicycle world if a part is described as
made of "alloy" it's generally an aluminum alloy.


--
- Frank Krygowski

[Emanuel Berg]

Frank Krygowski wrote:

>>> Today there was a guy with a kid bike and
>>> the saddle post was stuck in the pipe.
>>> He said it was because the frame was of

>>> "lättmetal", which is literally "light

OK, thanks for answers, makes sense to me.

BTW that shouldn't be "I haven't seen
anything", it should be EVERYTHING of
course. Hypoxia.

[John B Slocomb]

On Sun, 22 Apr 2018 15:43:26 +0200, Emanuel Berg <moa...@zoho.com>
wrote:

Aluminum alloys corrode at amazing rates if in contact with another
metal, particularly in the presence of water which provides an
electrolyte. Aluminum seat tubes in steel frames, for example.

The partial solution is to use a good antisieze, or even grease, to
insulate the parts.

[James]

On 23/04/18 10:48, John B Slocomb wrote:

>
> Aluminum alloys corrode at amazing rates if in contact with another
> metal, particularly in the presence of water which provides an
> electrolyte. Aluminum seat tubes in steel frames, for example.
>
> The partial solution is to use a good antisieze, or even grease, to
> insulate the parts.
>
>

But beware of greasing when there are carbon fibre parts involved.

http://forums.roadbikereview.com/components-wrenching/fyi-grease-carbon-seat-posts-40455.html

--
JS

[John B.]

On Mon, 23 Apr 2018 13:30:56 +1000, James <james.e...@gmail.com>
wrote:

Actually I have a carbon fiber seat post. Bought it at some swap meet
and never used it :-(
--
Cheers,

John B.