Sheared off a spoke nipple

I'm just impressed you could _LIFT_ one of those walmart bikes. 🙂 I picked up an 80's terry road
bike for my oldest and set strict rules on taking care of it. Even make her help with maintenence.
10 years old and she can change a flat, and climb some pretty good hills around here. The other
kids, especially the boys can't figure out why this girl can whup them racing up and down the
street. 🙂 Sounds like your son is in for bicycle maintenance 101, they appriciate it more when they
have to maintain it. Fixing flats and keeping it cleaned and oiled is a good place to start. 🙂

Ken Bessler said:

I was coming home from Wal Mart with my sons new 24" mountain bike. I was carrying it on my side
with straps while riding my Bianchi 12 speed road bike. Then all of a sudden the bike slipped and
one of it's pedals decided to interact with my rear spokes and popped one. Twang!

I checked the damage - the nipple had sheared off where it meets the rim so while the nipple was
toast, the spoke, although bent badly, was saveable. I jammed the bent spoke into a nearby pair
and limped home.

After I got home I removed the spoke and straightened it out. What I'm curious about is if nipples
are a designed weak link in the system? Is it normal for the spoke to survive so much abuse and
the nipple to shear off? Or did I just get lucky? Should I consider the spoke as damaged/fatigued
and replace it? It was bent about 20 degrees in 2 places. I have Sun Mistral 700mm 36 spoke alloy
rims - I'm kinda suprised that the nipple didn't just tear itself out of the aluminum.

Ken

P.S. My son (12) loves his new bike - he immediatley got 1-2 pounds of mud on it, put 2 holes in
the front tire and blew out the back tube by riding through a briar patch. He *walks* to
school tomorrow.......

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Mark Wolfe wolfenet.orgwolfenet.orgOpen ↗ gpg fingerprint = 42B6 EFEB 5414 AA18 01B7 64AC EF46 F7E6 82F6
8C71 sub UNIVERSAL::AUTOLOAD{ $UNIVERSAL::AUTOLOAD =~ s/::/ /; print "$UNIVERSAL::AUTOLOAD "};
hacker perl another just;

Ken Bessler said:

I was coming home from Wal Mart with my sons new 24" mountain bike. I was carrying it on my side
with straps while riding my Bianchi 12 speed road bike. Then all of a sudden the bike slipped and
one of it's pedals decided to interact with my rear spokes and popped one. Twang!

I checked the damage - the nipple had sheared off where it meets the rim so while the nipple was
toast, the spoke, although bent badly, was saveable. I jammed the bent spoke into a nearby pair and
limped home.

After I got home I removed the spoke and straightened it out. What I'm curious about is if nipples
are a designed weak link in the system? Is it normal for the spoke to survive so much abuse and the
nipple to shear off? Or did I just get lucky? Should I consider the spoke as damaged/fatigued and
replace it? It was bent about 20 degrees in 2 places. I have Sun Mistral 700mm 36 spoke alloy rims
- I'm kinda suprised that the nipple didn't just tear itself out of the aluminum.

Ken

To answer your question, nipples are not the weak link in a wheel. If the wheel is well built and
undamaged, the rim wears out first. I've never seen a nipple fail in tension, but I don't have the
vast experience a shop owner / mechanic will have with wheel damage. I do know that nipples often
pull through the rim when tension becomes too high. Also, cracks can form around the spoke holes in
rims as a prelude to failure. So, I'd suggest you do the following:

Check the rim carefully for damage like small cracks around the spoke holes. If it is cracked, it
should be replaced. Check the other spokes, all of them, carefully for nicks. Spokes with nicks will
fail and should be replaced. Don't re-use the bent spoke. If in the end all you find wrong is the
broken nipple, spend $1.00 and get a new spoke and nipple.

Steve Shapiro [email hidden]

Quoth Ken Bessler:

Quoted message said:

I was coming home from Wal Mart with my sons new 24" mountain bike. I was carrying it on my side
with straps while riding my Bianchi 12 speed road bike. Then all of a sudden the bike slipped and
one of it's pedals decided to interact with my rear spokes and popped one. Twang!

I checked the damage - the nipple had sheared off where it meets the rim so while the nipple was
toast, the spoke, although bent badly, was saveable. I jammed the bent spoke into a nearby pair
and limped home.

After I got home I removed the spoke and straightened it out. What I'm curious about is if nipples
are a designed weak link in the system? Is it normal for the spoke to survive so much abuse and
the nipple to shear off? Or did I just get lucky?

This sort of failure commonly suggests that the spokes used are slightly too short, so that they
don't extend into the head part of the nipple.

This requires the nipple to do all of the holding.

If you combine this with careless wheelbuilding (no lubrication of the spoke holes in the rim) and a
cheap eyeletless rims that may have burrs and sharp edges on the spoke holes, the building process
can cut into the underside of the nipple head, creating a stress riser.

Quoted message said:

Should I consider the spoke as damaged/fatigued and replace it? It was bent about 20 degrees in
2 places.

The spoke is probably OK, aside from being a bit too sort.

Sheldon "You Get What You Pay For" Brown +----------------------------------------------------+
| War is God's way of teaching Americans geography. | -Ambrose Bierce |
+----------------------------------------------------+ Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts shipped Worldwide
captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗

Ken Bessler said:

I was coming home from Wal Mart with my sons new 24" mountain bike. I was carrying it on my side
with straps while riding my Bianchi 12 speed road bike. Then all of a sudden the bike slipped and
one of it's pedals decided to interact with my rear spokes and popped one. Twang!

Quoted message said:

What I'm curious about is if nipples are a designed weak link in the system? Is it normal for the
spoke to survive so much abuse and the nipple to shear off? Or did I just get lucky?

The nipple didn't shear off, it got bent off, pried to one side. This is common and doesn't damage
rims with double wall sockets. I had the same effect when United Airlines baggage mashers broke a
spoke out of my rear wheel on the way overseas.

Quoted message said:

Should I consider the spoke as damaged/fatigued and replace it? It was bent about 20 degrees in 2
places. I have Sun Mistral 700mm 36 spoke alloy rims - I'm kinda suprised that the nipple didn't
just tear itself out of the aluminum.

Unless you can't straighten it to be visibly smooth, it will work fine. I assume it's a good grade
stainless spoke.

Jobst Brandt [email hidden]

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

Quoted message said:

The nipple didn't shear off, it got bent off, pried to one side. This is common and doesn't damage
rims with double wall sockets. I had the same effect when United Airlines baggage mashers broke a
spoke out of my rear wheel on the way overseas.

Unless you can't straighten it to be visibly smooth, it will work fine. I assume it's a good grade
stainless spoke.

Jobst Brandt

"Sheldon Brown" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

This sort of failure commonly suggests that the spokes used are slightly too short, so that they
don't extend into the head part of the nipple.

This requires the nipple to do all of the holding.

If you combine this with careless wheelbuilding (no lubrication of the spoke holes in the rim) and
a cheap eyeletless rims that may have burrs and sharp edges on the spoke holes, the building
process can cut into the underside of the nipple head, creating a stress riser.

Quoted message said:

Should I consider the spoke as damaged/fatigued and replace it? It was bent about 20
degrees in 2 places.

The spoke is probably OK, aside from being a bit too sort.

Sheldon "You Get What You Pay For" Brown

"Steve Shapiro" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

To answer your question, nipples are not the weak link in a wheel. If the wheel is well built and
undamaged, the rim wears out first. I've never seen a nipple fail in tension, but I don't have the
vast experience a shop owner / mechanic will have with wheel damage. I do know that nipples often
pull through the rim when tension becomes too high. Also, cracks can form around the spoke holes
in rims as a prelude to failure. So, I'd suggest you do the following:

Check the rim carefully for damage like small cracks around the spoke holes. If it is cracked, it
should be replaced. Check the other spokes, all of them, carefully for nicks. Spokes with nicks
will fail and should be replaced. Don't re-use the bent spoke. If in the end all you find wrong is
the broken nipple, spend $1.00 and get a new spoke and nipple.

Steve Shapiro

I just got back from my LBS where the owner inspected the rim. He told me that it's kinda rare for a
nipple to give out and unless the rim & spoke are high quality, they don't break - either the spoke
breaks or the nipple tears out of the rim. In my case, my spokes are stainless steel and my rims are
double wall with steel gussets around the nipples. I got lucky - again....

After replacing the nipple, I put the old one under magnification and it appears that Sheldon is
right - the spoke only went half way into the nipple and the threads on the head of the nipple are
un- damaged.

Thanks everyone for the advice!

Ken

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

Quoted message said:

Ken Bessler' may have said:

I checked the damage - the nipple had sheared off where it meets the rim so while the nipple was
toast, the spoke, although bent badly, was saveable. I jammed the bent spoke into a nearby pair
and limped home.

Aluminum nipple, perhaps? I've heard of it with those, but brass usually holds until the
spoke snaps.

After a close look under magnification, the nipple appears to be chrome plated brass.

Quoted message said:

Good rims will not fail before the spoke. As for not-so-good...one forlorn trail rider was seen
yesterday carrying his bike out with a dangling spoke (nipple intact) and two more pretzeled after
a stick did a kamikaze into the rear wheel. To call the rim "a no-name mass-market wheel" would be
appropriate. In this context, it could also be called "junque."

I had my LBS inspect the rear wheel when I went there to buy a nipple - He agrees that I got "lucky"
and on a cheaper rim, the nipple would have torn out. My rims are double wall aluminum with
stainless steel gussets. Not too bad for a $35 Bianchi 12 speed Salvation Army special, eh?

Ken

Ken Bessler said:

I just got back from my LBS where the owner inspected the rim. He told me that it's kinda rare for
a nipple to give out and unless the rim & spoke are high quality, they don't break - either the
spoke breaks or the nipple tears out of the rim. In my case, my spokes are stainless steel and my
rims are double wall with steel gussets around the nipples. I got lucky - again....

As I said, the spoke was pulled aside and that puts a "peeling" force on the nipple flange. I have
seen this occur a few times on socketed rims with no damage to the rim or spoke. Now that socketed
spokes are a thing of the past, we may not be so lucky.

Quoted message said:

After replacing the nipple, I put the old one under magnification and it appears that Sheldon is
right - the spoke only went half way into the nipple and the threads on the head of the nipple are
un- damaged.

Unless you have spoke threads exposed from the nipple, the spoke is engaged as far as it needs to
be. At that point the spoke is engaged in the nipple so that it extends to the bottom of the screw
driver slot. The recent such failure that I had left no threads remaining in the nipple flange.

Jobst Brandt [email hidden]

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

Quoted message said:

Ken Bessler said:

I just got back from my LBS where the owner inspected the rim. He told me that it's kinda rare
for a nipple to give out and unless the rim & spoke are high quality, they don't break - either
the spoke breaks or the nipple tears out of the rim. In my case, my spokes are stainless steel
and my rims are double wall with steel gussets around the nipples. I got lucky - again....

As I said, the spoke was pulled aside and that puts a "peeling" force on the nipple flange. I have
seen this occur a few times on socketed rims with no damage to the rim or spoke. Now that socketed
spokes are a thing of the past, we may not be so lucky.

Jobst Brandt [email hidden]

Ok, here's a dumb question - why are "socketed" rims a thing of the past? Seems like a good idea to
me. Is it a weight issue?

Ken

Ken Bessler' may have said:

I had my LBS inspect the rear wheel when I went there to buy a nipple - He agrees that I got
"lucky" and on a cheaper rim, the nipple would have torn out. My rims are double wall aluminum with
stainless steel gussets. Not too bad for a $35 Bianchi 12 speed Salvation Army special, eh?

I stand in awe of the master bargain hunter.

--
My email address is antispammed; pull WEEDS if replying via e-mail. Yes, I have a killfile. If I
don't respond to something, it's also possible that I'm busy.

Ken Bessler said:

Quoted message said:

As I said, the spoke was pulled aside and that puts a "peeling" force on the nipple flange. I
have seen this occur a few times on socketed rims with no damage to the rim or spoke. Now that
socketed spokes are a thing of the past, we may not be so lucky.

Quoted message said:

Ok, here's a dumb question - why are "socketed" rims a thing of the past? Seems like a good idea
to me. Is it a weight issue?

For the same reasons that rims like the MA-2 (with sockets) are no longer made. I don't understand
the marketing concepts behind this but that's the way it is. This is similar to chains. The 5-part
chain is also no longer made, even though, typically, the Regina CX-S chain outlasted current chains
by more than 5:1 in mileage. I suspect that MTB gears with 22t chainrings exceeded the tensile
strength of these chains. No one will make a chain that cannot take the pull of an overweight MTB
rider lunging on pedals with a micro sprocket. In fact more and more people are breaking chains from
what I read here.

Jobst Brandt [email hidden]

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

Quoted message said:

Ken Bessler writes:

Quoted message said:

Quoted message said:

Ok, here's a dumb question - why are "socketed" rims a thing of the past? Seems like a good idea
to me. Is it a weight issue?

For the same reasons that rims like the MA-2 (with sockets) are no longer made. I don't understand
the marketing concepts behind this but that's the way it is. This is similar to chains. The 5-part
chain is also no longer made, even though, typically, the Regina CX-S chain outlasted current
chains by more than 5:1 in mileage. I suspect that MTB gears with 22t chainrings exceeded the
tensile strength of these chains. No one will make a chain that cannot take the pull of an
overweight MTB rider lunging on pedals with a micro sprocket. In fact more and more people are
breaking chains from what I read here.

Jobst Brandt

Sounds like the industry is trying to sell more chains and rims....

For shame!

Ken (socketed and loving every $35, 12 speed Bianchi of it!)

Quoted message said:

I stand in awe of the master bargain hunter

me too!! another psot maybe.famous bargains. can you top the G-berg address?

ambrose, who had a boat maimed after him has the problem devolved in a light socket when he he said
"the plays the thing but the casting is bad." or to deplain-reality gets dissected and founded to
everyone's satifaction and then we go home. NIPPLES ARE COOL!! that's level one. we now agree
NIPPLES ARE COOL!! SO WE CAN GO HOME. YEAH HAW!! But sadly, we now ask why are the nipples failing,
which they are. and this means some of us will not go home untill the question of "why are these
nipples failing" gets an answre. Gee est le Mote, No? NIPPLES ARE NOT COOL. NIPPLES SUCK.THE
INDUSTRY IS COMPLACENT.UP AGAINST THE WAL EXPLETIVE DELETED! THE INDUSTRY IS RESTING ON ITS BUTT.
this kinds bs happens all the time. Poor Newton, right? thought he had it in the bag BUT NO!! Like
the guy that wrote standing on the outside pedal makes no diff in cornering power its just acrobatic
show off. Well ok dude now try it bopth sides 3 times each on wet pavement in your favorite downhill
flowing zinger.

"rot!!" ambrose said!! after his nipples rounded out and let go just before leaving for teajuana
"this is quantum!!"

Just out of interest, and because it would be most unusual for only one spoke to be short, are there
spoke threads showing at the tops of any nipples on the wheel? Was the broken spoke on the left or
right side?

In the past, I've considered it OK for my home built wheels if there are no threads visible above
the nipples although commonly they are a bit longer with the end of the spokes is between the bottom
and the top of the nipple screwdriver slot. It is common to make the spokes on the left side of the
rear wheel 1 or 2 mm longer than the right to achieve this thread engagement uniformly. In your
case, they may be the same length, leaving the left hand spokes short and, inadvertently, helping to
save your wheel. But we can not know the influence of spoke length on this kind of nipple failure
for sure since Jobst had a nipple break and I'm sure his spokes were sufficiently long. In any case,
I'm glad for your good fortune.

Steve Shapiro [email hidden]

Ken Bessler said:

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

Quoted message said:

Ken Bessler writes:

Quoted message said:

Quoted message said:

Ok, here's a dumb question - why are "socketed" rims a thing of the past? Seems like a good
idea to me. Is it a weight issue?

For the same reasons that rims like the MA-2 (with sockets) are no longer made. I don't
understand the marketing concepts behind this but that's the way it is. This is similar to
chains. The 5-part chain is also no longer made, even though, typically, the Regina CX-S chain
outlasted current chains by more than 5:1 in mileage. I suspect that MTB gears with 22t
chainrings exceeded the tensile strength of these chains. No one will make a chain that cannot
take the pull of an overweight MTB rider lunging on pedals with a micro sprocket. In fact more
and more people are breaking chains from what I read here.

Jobst Brandt

Sounds like the industry is trying to sell more chains and rims....

For shame!

Ken (socketed and loving every $35, 12 speed Bianchi of it!)

"Steve Shapiro" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Just out of interest, and because it would be most unusual for only one spoke to be short, are
there spoke threads showing at the tops of any nipples on the wheel? Was the broken spoke on the
left or right side?

No threads showing and the broken spoke went into the left side of the hub. I "plucked" the spokes
and adjusted the replacement nipple untill the spoke "twanged" like the others. Now, there was a bit
of differance in the tone of some spokes but the rim turns very true with no dicernable wobble.

Quoted message said:

In the past, I've considered it OK for my home built wheels if there are no threads visible above
the nipples although commonly they are a bit longer with the end of the spokes is between the
bottom and the top of the nipple screwdriver slot. It is common to make the spokes on the left
side of the rear wheel 1 or 2 mm longer than the right to achieve this thread engagement
uniformly. In your case, they may be the same length, leaving the left hand spokes short and,
inadvertently, helping to save your wheel. But we can not know the influence of spoke length on
this kind of nipple failure for sure since Jobst had a nipple break and I'm sure his spokes were
sufficiently long. In any case, I'm glad for your good fortune.

Steve Shapiro [email hidden]

Thanks, Steve....

Ken