Re: Lifetime of spokes?

[FlashSteve]

Bull****! I have wheels that are 8 or 9 years old, 30,000+ miles (much of it
in the rain) and I have never broken a spoke. I ride only hand-built,
pre-stressed and re-tensioned wheels with DT, Sapim, or Wheelsmith spokes. I
am 170 lbs, ride on O.K. roads.

So, I am no expert in wheel-building (there are MANY discussions in this group
on that subject), but the shop girl is feeding you an uninformed line of BS.

Steve Scarich

[Chris Neary]

>Her thought was
>that the stainless steel the spokes are made of is starting to "crystalize"
>and become brittle with age. This makes it prone to breaking.

This is a classic "old wive's tale" told by uneducated welders, etc.

The solid state of steels, stainless or otherwise, is a crystal. Your spoke
did not further "crystalize" in use.

>She did not
>think the problem was caused by looseness of some spokes.

Why not? If the quality of the wheel build was such that one spoke failed,
it is not out of the question that other spokes are experiencing similar
fatigue loadings and damage.

> Suggested fix was
>to re-spoke the wheel (~$50) or buy a new wheel (~$70) or just fix the
>spokes as they break (~$10 labor total plus 66 cents for each spoke). For
>now, I'm doing the last.

I vote for biting the bullet and having the wheel respoked or buying a new
wheel. Life's too short to be running back to the shop every time a spoke
pops, and at this point you've almost spent half the cash required to
re-spoke the wheel. I would try to find out who in the area has the best
reputation as a wheelbuilder, though - a professions go, wheelbuilding is as
much art as science.


Chris Neary


"Science, freedom, beauty, adventure: what more could
you ask of life? Bicycling combined all the elements I
loved" - Adapted from a quotation by Charles Lindbergh

[archer]

In article >,
says...
> I've been riding a hybrid bike with street tires for about three years on a
> daily basis (about 12 miles a day on average). Street and rail trail use
> only. No big impacts. Never had any spoke problems until a month ago when
> one spoke broke. Had that fixed at a local shop. Then yesterday, two more
> spokes broke. (All on rear wheel.) Took it into the local shop for repair
> and spoke with the service person about possable causes. Her thought was
> that the stainless steel the spokes are made of is starting to "crystalize"
> and become brittle with age. This makes it prone to breaking. She did not
> think the problem was caused by looseness of some spokes. Suggested fix was
> to re-spoke the wheel (~$50) or buy a new wheel (~$70) or just fix the
> spokes as they break (~$10 labor total plus 66 cents for each spoke). For
> now, I'm doing the last.
>
> Anybody have any ideas about this?

You shouldn't be breaking any spokes in normal riding no matter how old
the wheel is. Have the wheel properly tensioned (you can do it yourself
if you're careful), and you shouldn't break any more.


--
David Kerber
An optimist says "Good morning, Lord." While a pessimist says "Good
Lord, it's morning".

Remove the ns_ from the address before e-mailing.

[Terry Morse]

Peter Cole wrote:

> Spokes never break in the center. 90% of the time they break at the elbow, the
> rest at the threads, that's where the residual manufacturing/building stresses
> are.

Never say never. I've seen a spoke break in the middle before, and
it makes a pretty spectacular noise. The culprit was corrosion,
probably started at a surface scratch.
--
terry morse Palo Alto, CA http://www.terrymorse.com/bike/

[[email protected]]

Terry Morse writes:

>> Spokes never break in the center. 90% of the time they break at the
>> elbow, the rest at the threads, that's where the residual
>> manufacturing/building stresses are.

> Never say never. I've seen a spoke break in the middle before, and
> it makes a pretty spectacular noise. The culprit was corrosion,
> probably started at a surface scratch.

As I said, most of my spoke failures are from nicks made by the chain
falling into the spokes (because the end stops of today's derailleurs
are too short to prevent going past the lowest sprocket on my 6-speed
FW's) where the exception was a failure in the middle that showed no
indication for its failure showing no crack propagation, only a
sloping complete separation. When it went, it sounded no different
from any other spoke failure, like a small hammer blow on the hub.

Jobst Brandt

Palo Alto CA

[[email protected]]

Terry Morse writes:

>> Spokes never break in the center. 90% of the time they break at the
>> elbow, the rest at the threads, that's where the residual
>> manufacturing/building stresses are.

> Never say never. I've seen a spoke break in the middle before, and
> it makes a pretty spectacular noise. The culprit was corrosion,
> probably started at a surface scratch.

As I said, most of my spoke failures are from nicks made by the chain
falling into the spokes (because the end stops of today's derailleurs
are too short to prevent going past the lowest sprocket on my 6-speed
FW's). The exception was a failure in the middle that showed no
indication for its failure with no crack propagation, only a slightly
sloping complete separation and no necking. When it went, it sounded
no different from any other spoke failure, like a small hammer blow on
the hub.

Jobst Brandt

Palo Alto CA

[Peter Cole]

"Terry Morse" > wrote in message
...
> Peter Cole wrote:
>
> > Spokes never break in the center. 90% of the time they break at the elbow,
the
> > rest at the threads, that's where the residual manufacturing/building
stresses
> > are.
>
> Never say never. I've seen a spoke break in the middle before, and
> it makes a pretty spectacular noise. The culprit was corrosion,
> probably started at a surface scratch.

Sorry, I assumed stainless, I've long discarded anything that isn't. I've also
had a few fail where they were nicked by a chain, but I thought the topic was
fatigue, not accidents or rust.

From:
http://www.duke.edu/~hpgavin/papers/HPGavin-Wheel-Paper.pdf

"In 1984 and 1985, fatigue tests on stainless steel bicycle spokes were
carried out for Wheelsmith, Inc. at Stanford University. In 68 spokes the
failure occurred at the cold-worked elbow; in the remaining 8 spokes the
failure occurred at the threads."

[Chris Neary]

>>
>> Never say never. I've seen a spoke break in the middle before, and
>> it makes a pretty spectacular noise. The culprit was corrosion,
>> probably started at a surface scratch.
>
>Sorry, I assumed stainless, I've long discarded anything that isn't. I've also
>had a few fail where they were nicked by a chain, but I thought the topic was
>fatigue, not accidents or rust.

Stainless steel isn't immune to all forms of corrosion. Depending on the
grade, stress-corrosion cracking, usually associated with exposure to
chlorides (i.e, sweat or salt air), is a common failure mode.



Chris Neary


"Science, freedom, beauty, adventure: what more could
you ask of life? Bicycling combined all the elements I
loved" - Adapted from a quotation by Charles Lindbergh

[Chris Neary]

>Sure, but I don't think bicycle spokes are made from those alloys. Do you?


Well, what are they made of?

I'm guessing a 410 martensitic alloy or similar, which has a number of
corrosion failure modes at room temperature.



Chris Neary

[Steve McDonald]

Regardless of the cause of broken spokes, unless you learn to
replace and properly adjust them yourself, your money and time will
continue to be depleted by trips to bike shops. I always carry several
spare spokes taped to the frame and immediately replace broken ones with
the tools from my emergency repair kit. Riding on a wheel with a broken
spoke will stress the remaining spokes next to it and may lead to them
also breaking before long. It's also damaging to the rims and hubs to
run on an out-of-true wheel and will wear out a tire much faster.

Steve McDonald

[Peter Cole]

"Steve McDonald" > wrote in message
...
>
> Regardless of the cause of broken spokes, unless you learn to
> replace and properly adjust them yourself, your money and time will
> continue to be depleted by trips to bike shops.

If you fix the cause of broken spokes, they won't break anymore. After stress
relieving, you won't break many spokes unless you put a stick or chain into
them. In 40K+ miles, I've broken perhaps 2 spokes that weren't chain nicked,
and I weigh 235.

> I always carry several
> spare spokes taped to the frame and immediately replace broken ones with
> the tools from my emergency repair kit. Riding on a wheel with a broken
> spoke will stress the remaining spokes next to it and may lead to them
> also breaking before long. It's also damaging to the rims and hubs to
> run on an out-of-true wheel and will wear out a tire much faster.

Surely not in the time it takes to ride home?

[Steve McDonald]

Peter Cole wrote:

>If you fix the cause of broken spokes, they won't >break anymore. After
stress relieving, you won't >break many-------
_____________________________________

In a theoretical world, all bicycle parts would be the best quality
and would be installed and adjusted by experts. Spokes would last for
many years and the need to replace them would be no more common than
courteous motorists.

In our real world, many wheels will not be perfectly assembled and
spokes will break and need replacing. Sometimes, if a wheel has been
stressed by a mishap or by being used while poorly adjusted, even an
expert adjustment won't prevent broken spokes.

My number one bike has gone 4 years on 36-spoke wheels without a
single broken one. I loosened, then evenly and tightly readjusted them
when it was new and have gotten good results. But, on other bikes and
wheels, I have had broken spokes regularly, despite my best efforts at
adjustment. My large size and towing of heavy trailers was a major
cause of this. Even though I have had good luck recently, I would be
foolish to not expect broken spokes at any time and to be prepared to
replace them on the road. Often, I am 30 miles from home on a workout
and riding that far on a crooked wheel would cause some damage. When
one broken spoke is soon followed by others, I think the continuing
problem is often caused by damage to the adjacent spokes and rim, when
the bike is ridden some distance before a spoke is replaced.

Steve McDonald

[David Kerber]

In article <9xSWa.50014$YN5.39085@sccrnsc01>,
says...
> "Chris Neary" > wrote in message
> ...
> > >Sure, but I don't think bicycle spokes are made from those alloys. Do you?
> >
> >
> > Well, what are they made of?
> >
> > I'm guessing a 410 martensitic alloy or similar, which has a number of
> > corrosion failure modes at room temperature.
>
> I've not heard any reports of corrosion in stainless steel spokes, not even
> here in New England, where winter riding is quite a salty experience. I'm also
> a sailor, and haven't seen stainless corrosion there either. I'm guessing
> whatever alloys are being used for bike spokes, they're not susceptible to
> corrosion.

At least not at ambient temperatures.

--
Dave Kerber
Fight spam: remove the ns_ from the return address before replying!

REAL programmers write self-modifying code.

[mark freedman]

"303squadron" > wrote in message >...

Did it break at the elbow ?


> > that the stainless steel the spokes are made of is starting to "crystalize"

One LBS told me that galvanized spokes don't crystalize
like stainless steel. I suspect they just made more money
on glavanized spokes. :-(


> think the problem was caused by looseness of some spokes. Suggested fix was

You can read articles at www.sheldonbrown.com, read the faq,
search google groups for discussions fo spokes.

I bought a new (cheap) wheel from Bicycle Specialties in
Toronto. I specifically asked them to tension and true the
wheel. They said it was fine. After two weeks I was breaking
spokes (they were pretty loose to begin with). The flexing
tends to cause problems. Also, loose spokes allow the nipple to
unscrew, aggravating the existing lack of tension.

Speaking of which, I've replaced the two broken spokes and
tensioned the wheel, and I'm wondering if I should replace ALL
the spokes, since they were ridden loose. Intuitively, they'll
just keep breaking.


> to re-spoke the wheel (~$50) or buy a new wheel (~$70) or just fix the
> spokes as they break (~$10 labor total plus 66 cents for each spoke). For
> now, I'm doing the last.
>
Paying someone to replace one spoke at a time is an expensive
way to go. In my limited experience, unless there's specific damage,
e.g. cuts from the chain wedging between the large cog and the spokes,
they will just keep breaking one after t'other.


If you replace spokes yourself, it's a nuisance but just costs
time and $1 for a spoke.

If you can buy a decent wheel for $70 (properly tensioned,
good quality hub) it seems a better choice than paying $50
to rebuild the old wheel (old hub and rim). You can always
tinker with the old wheel yourself. It's a useful skill.

hth


>

[Peter Cole]

"Steve McDonald" > wrote in message
...
>
> My number one bike has gone 4 years on 36-spoke wheels without a
> single broken one. I loosened, then evenly and tightly readjusted them
> when it was new and have gotten good results. But, on other bikes and
> wheels, I have had broken spokes regularly, despite my best efforts at
> adjustment.

Doesn't sound like you're stress relieving your spokes. As I said earlier, if
you do that, you won't break spokes from fatigue.

[Peter Cole]

"David Kerber" > wrote in message
...
> In article <9xSWa.50014$YN5.39085@sccrnsc01>,
> says...

> > I've not heard any reports of corrosion in stainless steel spokes, not
even
> > here in New England, where winter riding is quite a salty experience. I'm
also
> > a sailor, and haven't seen stainless corrosion there either. I'm guessing
> > whatever alloys are being used for bike spokes, they're not susceptible to
> > corrosion.
>
> At least not at ambient temperatures.

Who uses spokes in "non-ambient" temperatures?

[Peter Cole]

"Chris Neary" > wrote in message
...
>
> The key clue in failure in question may very well be the surface scratch,
> which could two possible contributing factors:
>
> 1) Temporarily removed the protective oxide layer which makes stainless
> steels, "stainless"; and
>
> 2) Locally concentrated stresses.
>
> Without seeing the spoke in question this is all just speculation,
> obviously.
>

There was no "spoke in question". All this is just somebody's hypothetical. My
point was that I have never seen the "spoke in question" (corroded stainless
steel), and if I haven't by now, I don't expect to in the future. I think it
is an invented problem.

[Just zis Guy, you know?]

On Sat, 02 Aug 2003 18:17:44 GMT, Chris Neary
> wrote:

>1) Temporarily removed the protective oxide layer which makes stainless
>steels, "stainless"; and

Really?

Guy
===
** WARNING ** This posting may contain traces of irony.
http://www.chapmancentral.com
New! Improved!! Now with added extra Demon!

[Peter Cole]

"mark freedman" > wrote in message
m...
> "303squadron" > wrote in message
>...
>
>
> You can read articles at www.sheldonbrown.com, read the faq,
> search google groups for discussions fo spokes.
>
> I bought a new (cheap) wheel from Bicycle Specialties in
> Toronto. I specifically asked them to tension and true the
> wheel. They said it was fine. After two weeks I was breaking
> spokes (they were pretty loose to begin with). The flexing
> tends to cause problems. Also, loose spokes allow the nipple to
> unscrew, aggravating the existing lack of tension.

If you read the FAQ yourself, you'll see that the main reason spoke fail is
from residual stresses. Stress relieving the spokes is the only way to
eliminate this problem.

[Chris Neary]

>>1) Temporarily removed the protective oxide layer which makes stainless
>>steels, "stainless"; and
>
>Really?

Yep.

On exposure to air, a layer of chromium oxide forms on stainless steel. This
compound is extremely corrosion resistant.

If it is removed (by grinding or similar means), corrosion of the stainless
could occur before the layer is reestablished.

Chemical treatments are often used to promote high quality oxide layers on
stainless steels. Ref:
http://www.eng-tips.com/gviewthread.cfm/lev2/16/lev3/58/pid/404/qid/64445



Chris Neary


"Science, freedom, beauty, adventure: what more could
you ask of life? Bicycling combined all the elements I
loved" - Adapted from a quotation by Charles Lindbergh