Spontaneous Spoke Combustion

Plain old front wheel only a few years old, low miles - Velocity twin hollow rim, Deore hub, straight gauge stainless spokes - sitting in a box in my basement for about 2 years.

Basement is temp and humidity controlled - typically 55 to 65 degrees, I try not to let the humidity get above 60%.

Pulled it out of the box today - 6 broken spokes. Most ~2 inches from the hub, 4 in a row on one side. Looks like someone cut them with wire cutters.

I think I see the culprit - some sort of corrosion. If you look closely you can see little bits of rust along with little white deposits.

But still... what the heck? I have even cheaper wheels sitting in this environment for 15 years, and I see no evidence of spokes about to evaporate.

Seems like a bad batch of spokes to me.

Anyone ever seen this before?

Kyle

On 16/12/2015 16:20, KyleBH wrote:
Plain old front wheel only a few years old, low miles - Velocity twin hollow rim, Deore hub, straight gauge stainless spokes - sitting in a box in my basement for about 2 years.

Basement is temp and humidity controlled - typically 55 to 65 degrees, I try not to let the humidity get above 60%.

Pulled it out of the box today - 6 broken spokes. Most ~2 inches from the hub, 4 in a row on one side. Looks like someone cut them with wire cutters.

I think I see the culprit - some sort of corrosion. If you look closely you can see little bits of rust along with little white deposits.

But still... what the heck? I have even cheaper wheels sitting in this environment for 15 years, and I see no evidence of spokes about to evaporate.

Seems like a bad batch of spokes to me.

Anyone ever seen this before?

Mice.

Actually, if your mice can cut stainless, can you let me know where you
live so I can avoid it?

More seriously, stainless spokes will last dozens of years even when
treated badly, and non-stainless spokes left clean in an environment
like you describe will be fine for a similar length of time, so you've
got an exceptional problem. Are you sure somebody hasn't taken wire
cutters to them to freak you out?

Got decent macro close-up pictures of the broken spoke ends?

searching is difficult, would start off waiting for something like 'types of bearing wear'

but not....

generic spokes do funny stuff, DT SAPIM et al do not.

cuts are usually saw marked with ridges or cut with shear/diagonal cutters leaving 2 surfaces joining at a wire/spoke middle diameter longer than the OD wire/spoke area
.....an angle off the uncut area.

acids/bases would leave a wash residue along the fully corroded spot.

thin gauge spokes could corrode and snap while not looking at them....like not boiling water. Generic spokes. Butbutbut the entire spoke would show signs of corrosion

Not seeing general corrosion poses a mystery. Hard figuring why corrosion would not spray elsewhere but again generic spokes may show weal spots here and there...possibly of not the same material as elsewhere in the system.

real off quality control b-b-b-bbbbbbaaaaaaaaaaaaaaaaaaaaaaaaaaaaaad

On Wed, 16 Dec 2015 23:38:43 +0100, Andreas Oehler
wrote:

Wed, 16 Dec 2015 08:20:26 -0800 (PST), KyleBH:

Plain old front wheel only a few years old, low miles - Velocity
twin hollow rim, Deore hub, straight gauge stainless spokes - sitting
in a box in my basement for about 2 years.

Pulled it out of the box today - 6 broken spokes. Most ~2 inches from
the hub, 4 in a row on one side. Looks like someone cut them with wire
cutters.

I think I see the culprit - some sort of corrosion. If you look closely
you can see little bits of rust along with little white deposits.

I have seen a few similar cases lately - stainless steel spokes broken
somewhere in the middle with brown spots of corrosion visible under a
magnifying lens. All those wheels were used on salted roads in winter and
the salty coating on the spokes never really removed. There are rumours
that modern "wet salt" used on german streets today contains more MgCl2
and KCl than the "good old" NaCl and causes stress corrosion cracking on
some variants of stainless steel.

What is the manufacturer and type of your broken spokes? The spokes broken
here are all from Sapim. But Sapim seems to be the biggest supplier for
spokes on high quality wheel in Europe - so no wonder to found their
spokes...

I also had cases of chains with stainless steel link plates cracking
around the pins some month after use in salty slush. This was on my bike
with studded tires which I only use in winter. This bike has 10 year old
DT spokes - and they don't seem to bother with the salt on them.

Andreas - no signs of Winter here so far

One thing is that "stainless steel" is not necessarily corrosion
proof. See http://www.estainlesssteel.com/corrosion.shtml or
http://www.bssa.org.uk/topics.php?article=95
for a discussion of how stainless works.
--
cheers,

John B.

On 17/12/2015 00:13, John B. wrote:

One thing is that "stainless steel" is not necessarily corrosion
proof. See http://www.estainlesssteel.com/corrosion.shtml or
http://www.bssa.org.uk/topics.php?article=95
for a discussion of how stainless works.

The other day I was reading the book "Ignition", which is the story of
liquid propellants in rockets. (can be found on the web, it's not too long).

One of the propellants he describes is red fuming nitric acid, ie close
to 100% HNO3. They put it in steel containers, thought it was ok, but a
while later discovered the hard way that it did attack them and the
resulting sludge is very nasty indeed.

The fix turned out to be add 5% of an even more nasty thing - HF. The
hydroflouric acid reacts with the steel to form a flouride layer which
is actually resistant to both acids, and the entire thing is stable.

On Wednesday, December 16, 2015 at 4:45:12 PM UTC-8, Clive George wrote:
On 17/12/2015 00:13, John B. wrote:

One thing is that "stainless steel" is not necessarily corrosion
proof. See http://www.estainlesssteel.com/corrosion.shtml or
http://www.bssa.org.uk/topics.php?article=95
for a discussion of how stainless works.

The other day I was reading the book "Ignition", which is the story of
liquid propellants in rockets. (can be found on the web, it's not too long).

One of the propellants he describes is red fuming nitric acid, ie close
to 100% HNO3. They put it in steel containers, thought it was ok, but a
while later discovered the hard way that it did attack them and the
resulting sludge is very nasty indeed.

The fix turned out to be add 5% of an even more nasty thing - HF. The
hydroflouric acid reacts with the steel to form a flouride layer which
is actually resistant to both acids, and the entire thing is stable.

mmmmmmm....flouride.....ahhhhhh

On Wednesday, December 16, 2015 at 7:45:12 PM UTC-5, Clive George wrote:
On 17/12/2015 00:13, John B. wrote:

One thing is that "stainless steel" is not necessarily corrosion
proof. See http://www.estainlesssteel.com/corrosion.shtml or
http://www.bssa.org.uk/topics.php?article=95
for a discussion of how stainless works.

The other day I was reading the book "Ignition", which is the story of
liquid propellants in rockets. (can be found on the web, it's not too long).

One of the propellants he describes is red fuming nitric acid, ie close
to 100% HNO3. They put it in steel containers, thought it was ok, but a
while later discovered the hard way that it did attack them and the
resulting sludge is very nasty indeed.

The fix turned out to be add 5% of an even more nasty thing - HF. The
hydroflouric acid reacts with the steel to form a flouride layer which
is actually resistant to both acids, and the entire thing is stable.

HF is used in sewers ?

The Raleigh here came with original equipment. 14/15 Gauge spokes.

Spokes snapped in middle after hmmmmm 1000 miles ? bink.....

spokes were crusty with corrosion not everywhere but generally then in places rotten right thru past stresses.

The well used Coleman one bottle stove head did this tonight. Fell out of the van rear when opening doors. Bent the bottles thread head. bending the stove level cracked the rotting reflector/pot foundation.

SURPRISE. off course had not examined in 4-5 years.

Good intentions. There is a can of spam around but...used 3x...weak willed post dinner.

Nowhere. I cannot remember wiping spokes down after a rain...but no salt here wuhwuhwuh ceptin' in the gulf.

We suffer dew point rot. The dew point distills salt out of the air placing it mostly in unseen crevices on your birdcage Maserati n then Dude you are XXXXX fersure. insidious.

word program caps Maserati!

On Wednesday, December 16, 2015 at 7:19:49 PM UTC-6, wrote:
On Wednesday, December 16, 2015 at 7:45:12 PM UTC-5, Clive George wrote:
On 17/12/2015 00:13, John B. wrote:

One thing is that "stainless steel" is not necessarily corrosion
proof. See http://www.estainlesssteel.com/corrosion.shtml or
http://www.bssa.org.uk/topics.php?article=95
for a discussion of how stainless works.

The other day I was reading the book "Ignition", which is the story of
liquid propellants in rockets. (can be found on the web, it's not too long).

One of the propellants he describes is red fuming nitric acid, ie close
to 100% HNO3. They put it in steel containers, thought it was ok, but a
while later discovered the hard way that it did attack them and the
resulting sludge is very nasty indeed.

The fix turned out to be add 5% of an even more nasty thing - HF. The
hydroflouric acid reacts with the steel to form a flouride layer which
is actually resistant to both acids, and the entire thing is stable.

HF is used in sewers ?

The Raleigh here came with original equipment. 14/15 Gauge spokes.

Spokes snapped in middle after hmmmmm 1000 miles ? bink.....

spokes were crusty with corrosion not everywhere but generally then in places rotten right thru past stresses.

The well used Coleman one bottle stove head did this tonight. Fell out of the van rear when opening doors. Bent the bottles thread head. bending the stove level cracked the rotting reflector/pot foundation.

SURPRISE. off course had not examined in 4-5 years.

Good intentions. There is a can of spam around but...used 3x...weak willed post dinner.

Nowhere. I cannot remember wiping spokes down after a rain...but no salt here wuhwuhwuh ceptin' in the gulf.

We suffer dew point rot. The dew point distills salt out of the air placing it mostly in unseen crevices on your birdcage Maserati n then Dude you are XXXXX fersure. insidious.

word program caps Maserati!

Could the spokes be from the bad batch in 2008?
http://forums.roadbikereview.com/eas...er-280263.html

Search: dew point charts

See if a chart data fits

On 17/12/15 01:13, John B. wrote:
On Wed, 16 Dec 2015 23:38:43 +0100, Andreas Oehler
wrote:

Wed, 16 Dec 2015 08:20:26 -0800 (PST), KyleBH:

Plain old front wheel only a few years old, low miles - Velocity
twin hollow rim, Deore hub, straight gauge stainless spokes - sitting
in a box in my basement for about 2 years.

Pulled it out of the box today - 6 broken spokes. Most ~2 inches from
the hub, 4 in a row on one side. Looks like someone cut them with wire
cutters.

I think I see the culprit - some sort of corrosion. If you look closely
you can see little bits of rust along with little white deposits.

I have seen a few similar cases lately - stainless steel spokes broken
somewhere in the middle with brown spots of corrosion visible under a
magnifying lens. All those wheels were used on salted roads in winter and
the salty coating on the spokes never really removed. There are rumours
that modern "wet salt" used on german streets today contains more MgCl2
and KCl than the "good old" NaCl and causes stress corrosion cracking on
some variants of stainless steel.

What is the manufacturer and type of your broken spokes? The spokes broken
here are all from Sapim. But Sapim seems to be the biggest supplier for
spokes on high quality wheel in Europe - so no wonder to found their
spokes...

I also had cases of chains with stainless steel link plates cracking
around the pins some month after use in salty slush. This was on my bike
with studded tires which I only use in winter. This bike has 10 year old
DT spokes - and they don't seem to bother with the salt on them.

Andreas - no signs of Winter here so far

One thing is that "stainless steel" is not necessarily corrosion
proof. See http://www.estainlesssteel.com/corrosion.shtml or
http://www.bssa.org.uk/topics.php?article=95
for a discussion of how stainless works.

That was very useful. Also in wurds I can unnerstan :-)