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

Search: dew point charts

See if a chart data fits

yeah, my 544 was parked outside at https://goo.gl/EqUZGq

inside the 544 was a steel toolbox with '70's Craftsmen sockets

sockets showed rust spots....

cleaned Craftsmans then oiler with thinned linseed, resolving the dew point salt deposits.

and on the Volvo

On 12/17/2015 7:54 AM, wrote:
yeah, my 544 was parked outside at https://goo.gl/EqUZGq

inside the 544 was a steel toolbox with '70's Craftsmen sockets

sockets showed rust spots....

cleaned Craftsmans then oiler with thinned linseed, resolving the dew point salt deposits.

and on the Volvo


Right. Metals just sit around all day scheming to find a
lower energy state:

http://www.yellowjersey.org/photosfr...t/DAMPCRNK.JPG

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

1 April, 1971

aluminum oxide forms immediately on lost aluminum alloys but not solder able aluminum alloy is type 1 ?

if a slim sliver of crank alloy is sliced off, is this solderable ?

or braze able ?

that is a mess. how polish out ?

On 12/17/2015 5:30 PM, wrote:
1 April, 1971

aluminum oxide forms immediately on lost aluminum alloys but not solder able aluminum alloy is type 1 ?

if a slim sliver of crank alloy is sliced off, is this solderable ?

or braze able ?

that is a mess. how polish out ?


We often note when asked to work with corroded parts that we
can't 'make it go away'. The rust or aluminum oxide is where
you once had metal, which is gone.

An oxidized pitted crank may be smoothed with successively
finer grades of wet sandpaper and finished on a cotton
polishing wheel if time and money are not critical. That
won't help any deep pits or unseen cracks/voids some of
which may be compromised by water and/or salt penetration.
Most aluminum cranks are anodized, and so need to be
completely polished on all surfaces to get a uniform look,
which is quite tedious considering they are no longer very
expensive. Then too, a polished crank is less corrosion
resistant than an anodized crank...

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

1 April, 1971

yes, advice well taken


https://www.google.com/#tbm=shop&q=m...69337098308413

On Thu, 17 Dec 2015 17:42:45 -0600, AMuzi wrote:

We often note when asked to work with corroded parts that we
can't 'make it go away'. The rust or aluminum oxide is where
you once had metal, which is gone.

An oxidized pitted crank may be smoothed with successively
finer grades of wet sandpaper and finished on a cotton
polishing wheel if time and money are not critical. That
won't help any deep pits or unseen cracks/voids some of
which may be compromised by water and/or salt penetration.
Most aluminum cranks are anodized, and so need to be
completely polished on all surfaces to get a uniform look,
which is quite tedious considering they are no longer very
expensive. Then too, a polished crank is less corrosion
resistant than an anodized crank...

Well, you can always fill the cracks, crevasses, holes, pits, and
gouges with stainless steel epoxy putty.
http://www.winnerindustrialsupply.com/index.php?view=product_detail&product_id=367
http://www.amazon.com/Loctite-97443-Fixmaster-Stainless-Minutes/dp/B001HWFHXU
It won't make the spoke any stronger, but it will look good... until
it breaks.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558