Suzy Jackson - Really [censored] Framebuilder

Carl Brewer said:

<snip>

Nothing lasts forever, but titanium will be the closest 🙂

Isn't the secret of comedy in the timing? What is the fatigue life of titanium?

Riding home last night & something wasn't didn't feel right. Strange noise too...

Closer inspection revealed a cracked chainstay! 🙁 🙁

Here is the crack. The crack has started from some chain suck damage.

There is more damage hidden behind the chainrings than I though. Bugger! This was the bike I was planning to take on the Bike 'n Wheels trip. 😠

Bikesoiler said:

Carl Brewer said:

<snip>

Nothing lasts forever, but titanium will be the closest 🙂

Isn't the secret of comedy in the timing? What is the fatigue life of
titanium?

That depends on how it's stressed 🙂

Graeme said:

Carl Brewer <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

steel=>rust

And aluminium => aluminium oxide.

Which is actually a good thing, because the Aluminum oxide protects from
further corrosion, unlike rust in steel. This oxide coating sticks to
the surface of the metal as long as the pH of the surroundings is
between 4.5 and 9. Ie, Don't take it swimming in the ocean, or at least
hose it off with plain water.

--
Brett

On 7 Apr 2005 02:50:53 GMT, Graeme <[email hidden]>

Quoted message said:

Carl Brewer <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

steel=>rust

And aluminium => aluminium oxide. Perhaps not at the same rate, but it
happens.

Aluminium oxide forms a protective layer that prevents further
corrosion, iron oxides form a gas-perrmeable layer that provides no
corrosion protection.

Sacrificial anode protection will delay the
inevitable, of course, and make it much harder to weld
(is gal harder to braze too? I'm not sure). Welds, where it's
almost impossible to get the metalurgy such that there's no
dissimmilar metals, are very brittle and weld sites are highly
stressed, as well as being more vulnerable to corrosion (dissimiliar
metal junctions etc). I'd guess that brazing is just as bad from
a corrosion POV, as you're mixing bronze with iron, so you'll
get electrolysis. Which one goes first? I haven't looked at
a REDOX table for _years_ 🙂

Golly, that carbon composite looks nice from this angle 🙂
Corrosion? Who?

Quoted message said:

However, if you look after a decent bike, whatever the frame
material it should last a long time (although reportedly longer if it's
steel).

If it never gets wet and/or scratched and there's no funky
impurities in the welds, sure, or it's covered in zinc, or it's made
of stainless (weld *that* for fun and profit!).

quote='Brett'Graeme said:

Carl Brewer <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

steel=>rust

And aluminium => aluminium oxide.

Which is actually a good thing, because the Aluminum oxide protects from
further corrosion, unlike rust in steel. This oxide coating sticks to
the surface of the metal as long as the pH of the surroundings is
between 4.5 and 9. Ie, Don't take it swimming in the ocean, or at least
hose it off with plain water.

--
Brett[/QUOTE]
He he, you have heard of aluminum boats I guess? I think the aluminium oxide reforms quickly after a dip in the ocean, if that even would cause to come off in the first place.

Claes said:

Brett said:

Graeme said:

Carl Brewer <[email hidden]> wrote in
news:[email hidden]:

>steel=>rust

And aluminium => aluminium oxide.

Which is actually a good thing, because the Aluminum oxide protects
from
further corrosion, unlike rust in steel. This oxide coating sticks to
the surface of the metal as long as the pH of the surroundings is
between 4.5 and 9. Ie, Don't take it swimming in the ocean, or at
least
hose it off with plain water.

--
Brett

He he, you have heard of aluminum boats I guess? I think the aluminium
oxide reforms quickly after a dip in the ocean, if that even would
cause to come off in the first place.

Don't aluminium boats use sacrificial anodes?

Brett said:

Don't aluminium boats use sacrificial anodes?

I don't think so? Boats, like bikes, are best made from composites 🙂

Claes <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

He he, you have heard of aluminum boats I guess? I think the aluminium
oxide reforms quickly after a dip in the ocean, if that even would
cause to come off in the first place.

I've seen a few older Grumman aluminium open canoes that have corroded
through in one or two small spots (just enough to let in enough water to
keep your feet cool). I think I'll stick to my plastic laminate Old Town.
Same goes for my bike, I'll not be swapping my aluminium Cannondale for a
composite! 🙂

Graeme

"Ken Oaf" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Wed, 6 Apr 2005 11:37:08 +1000, suzyj

Quoted message said:

Quoted message said:

This grasshopper needs to do some more learning about brazing,
methinks. Just because it looks nice and works when you first ride it,
doesn't mean it's still going to be good 10,000km down the track.

You brazed it?

Not a good method if you want structural strength.

not an "easy" method if you want structural strength.
but easier to make it look nice
i would say luged brazed tubes would be stronger than the same tubes MIG
welded

Quoted message said:

It would have been better to use a MIG welder.

an "easier" method if you want structural strength. (on tubes this thin you
wouldnt want any undercut, and what sort of wire are you going to use?)
not an "easy" method if you want it to look nice

stu

dont be to hard on yourself suzy, i make it about 5.4 million cycles, and
for most people 10000km is a lifetime 🙂

Brett <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Claes said:

Brett said:

Graeme wrote:

>Carl Brewer <[email hidden]> wrote in
>news:[email hidden]:
>
>
>
>>steel=>rust
>
>And aluminium => aluminium oxide.

Which is actually a good thing, because the Aluminum oxide protects
from
further corrosion, unlike rust in steel. This oxide coating sticks
to the surface of the metal as long as the pH of the surroundings is
between 4.5 and 9. Ie, Don't take it swimming in the ocean, or at
least
hose it off with plain water.

--
Brett

He he, you have heard of aluminum boats I guess? I think the
aluminium oxide reforms quickly after a dip in the ocean, if that
even would cause to come off in the first place.

Don't aluminium boats use sacrificial anodes?

The boats - no

The engines (full of cheap steel/aluminium and magnesium) - yes (usually
on the leg of the outboard)

If you have inboards with bronze or steel screws (props) then you need
to replace them about once every two to three years. Bronze looks
really cool after a few years exposure without protection particularly
when some hits a rock bar with them.

Large aluminium craft (ferry's etc) normally have them fixed to the
keel.

Cheers

Brett, Brad, Craig, Greg, Kevin (pick one - other people seem to)

Carl Brewer <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

On 7 Apr 2005 02:50:53 GMT, Graeme <[email hidden]>

Quoted message said:

Carl Brewer <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

steel=>rust

And aluminium => aluminium oxide. Perhaps not at the same rate, but it
happens.

Aluminium oxide forms a protective layer that prevents further
corrosion, iron oxides form a gas-perrmeable layer that provides no
corrosion protection.

Sacrificial anode protection will delay the
inevitable, of course, and make it much harder to weld
(is gal harder to braze too? I'm not sure). Welds, where it's

Almost impossible to weld or braze galvanised metals properly. Because
the gal is only a very thin layer of a different layer (zinc of course)
it heats much quicker and normally crazes. You just strip it back and
cold gal the joint when you are finished. At least for water pipes. I
don't know how this will go with frames.

Cheers

Brett, Craig, Brad, etc etc

Brett said:

Brett <[email hidden]>

Quoted message said:

Don't aluminium boats use sacrificial anodes?

The boats - no

Cause the manufacturer figures they'll never get enough use to corrode
properly? ;-)

Quoted message said:

Large aluminium craft (ferry's etc) normally have them fixed to the
keel.

ahhh..

Quoted message said:

Cheers

Brett, Brad, Craig, Greg, Kevin (pick one - other people seem to)

hehe, my wifes grandmother still calls me Brad after 15 years...

--
Brett

On Wed, 06 Apr 2005 06:32:57 GMT, Ken Oaf <[email hidden]>
wrote in aus.bicycle:

Quoted message said:

You brazed it?

Not a good method if you want structural strength.

It would have been better to use a MIG welder.

When I was doing my TAFE welding course the instructor said that a
brazed joint is as strong as a welded one and proved it in a test jig.

Regards
Bruce

Gemma_k said:

What was the method of faulure? Photos please!

Sure. Here's my shame, in all it's glory:

[IMG]atnf.csiro.auaudax post mortem 1.jpgOpen ↗[/IMG]
[IMG]atnf.csiro.auaudax post mortem 2.jpgOpen ↗[/IMG]
[IMG]atnf.csiro.auaudax post mortem 3.jpgOpen ↗[/IMG]

The first pic shows where the failure started from. Note the oxidation on the tube.

The second pic shows the other side.

The last pic shows what happened to the bottom bracket shell.

I suspect it was a combination of inadequate heat in the bottom bracket, too much on the tube, and inadequate cleaning of the tube and shell beforehand.

Regards,

Suzy

suzyj said:

Gemma_k said:

What was the method of faulure? Photos please!

Sure. Here's my shame, in all it's glory:

[image:
http://www.atnf.csiro.au/~sjackson/frame/audax_post_mortem_1.jpg]
[image:
http://www.atnf.csiro.au/~sjackson/frame/audax_post_mortem_2.jpg]
[image:
http://www.atnf.csiro.au/~sjackson/frame/audax_post_mortem_3.jpg]

The first pic shows where the failure started from. Note the oxidation
on the tube.

The second pic shows the other side.

The last pic shows what happened to the bottom bracket shell.

I suspect it was a combination of inadequate heat in the bottom
bracket, too much on the tube, and inadequate cleaning of the tube and
shell beforehand.

Is that rust on the seat tube? Looks like the failure was a while coming.

You'd think that for $100/litre, the paint would have better tensile
qualities ;-)

--
Brett "Still in awe that you built it in the first place"

NoZX6R <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Ken Oaf said:

suzyj said:

This grasshopper needs to do some more learning about brazing,
methinks. Just because it looks nice and works when you first ride
it, doesn't mean it's still going to be good 10,000km down the track.

You brazed it?

Not a good method if you want structural strength.

It would have been better to use a MIG welder.

Cmon Ken that's bollocks 😉 A brazed lugged frame can be plenty
strong.

Suzy's frame is not cracked _because_ it's brazed, it's cracked
because the joint is bad (Sorry Suzy, I wish I could make frames as
crappy as yours 😉

BTW, I reckon you should cut all the joints open to see how good they
were, and then build another frame 🙂

He is right that structural welds are generally formed with MIG, or more
frequently overhead TIG, think welded beams or bolt flanges. This is a
combination of production and the nature of the welds (large surface
areas. The steel/metal is also important. Most structural elements are
relatively thick to avoid slenderness issues and have relatively low
carbon contents (lower tensial capacity). High Carbon steels like steel
reinforcing are generally only tacked to avoid heat issues. Where they
are used in fabrication they are generally heat treated and quenched
progressively.

A bike tube is both very slender and high tensial. Unless you wanted to
muck about with heat treatment processes or you were using machine
welding (low contact time) combined with oversize elements (normal mass
production) then brazing would be one of the better ways to do it given
that there is less heat involved. With the surface area of the welds
the properties of the welding rod (tensial strength) are not going to
make a lot of difference.

Just my thoughts. I wish I had the cojones/ability to try making a
track frame but.....

Brett, Brad, Greg etc

Brett said:

NoZX6R <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Ken Oaf said:

On Wed, 6 Apr 2005 11:37:08 +1000, suzyj
<[email hidden]> wrote:

>This grasshopper needs to do some more learning about brazing,
>methinks. Just because it looks nice and works when you first ride
>it, doesn't mean it's still going to be good 10,000km down the track.

You brazed it?

Not a good method if you want structural strength.

It would have been better to use a MIG welder.

Cmon Ken that's bollocks 😉 A brazed lugged frame can be plenty
strong.

Suzy's frame is not cracked _because_ it's brazed, it's cracked
because the joint is bad (Sorry Suzy, I wish I could make frames as
crappy as yours 😉

BTW, I reckon you should cut all the joints open to see how good they
were, and then build another frame 🙂

He is right that structural welds are generally formed with MIG, or more
frequently overhead TIG, think welded beams or bolt flanges. This is a
combination of production and the nature of the welds (large surface
areas. The steel/metal is also important. Most structural elements are
relatively thick to avoid slenderness issues and have relatively low
carbon contents (lower tensial capacity). High Carbon steels like steel
reinforcing are generally only tacked to avoid heat issues. Where they
are used in fabrication they are generally heat treated and quenched
progressively.

A bike tube is both very slender and high tensial. Unless you wanted to
muck about with heat treatment processes or you were using machine
welding (low contact time) combined with oversize elements (normal mass
production) then brazing would be one of the better ways to do it given
that there is less heat involved. With the surface area of the welds
the properties of the welding rod (tensial strength) are not going to
make a lot of difference.

Just my thoughts. I wish I had the cojones/ability to try making a
track frame but.....

Brett, Brad, Greg etc

Good points. Also the use of high quality steel cast sockets to join
large industrial girders is clearly impractical, so making direct
comparisons with bicycle construction isn't really a good argument.

Marty