Busting the same spoke twice, what's going on?

Busting the same spoke twice, what's going on?

Post by Dave » Sun, 07 Apr 2013 02:34:22


Hey all,

I rebuilt some trusty old hubs with new rims and spokes (DA 7700 hubs, Sapim Race 14/15, Velocity A23 rims) using a cheapo truing stand and tensioning by feel but I'm decently skilled at this so the wheels turned out nicely (or so I thought).

Anyway, after maybe 1000 miles of use I broke a rear NDS spoke at the *** during a ride, didn't notice it happen, wasn't because of a severe impact.  I replaced it with a 14 gauge spoke of the same length and trued it back up.  Now after a couple hundred additional miles I've found I've busted the replacement spoke.

What the heck?  I find it really peculiar that both breaks happened in the same spot.  I'm not a great wheelbuilder but I've been building my own for many years and prior to this I'd never busted a spoke.  The rim seemed fine while building it.

Any advice much appreciated.

Dave

 
 
 

Busting the same spoke twice, what's going on?

Post by Dan » Sun, 07 Apr 2013 03:18:39


Quote:
> Hey all,

> I rebuilt some trusty old hubs with new rims and spokes (DA 7700 hubs, Sapim Race 14/15, Velocity A23 rims) using a cheapo truing stand and tensioning by feel but I'm decently skilled at this so the wheels turned out nicely (or so I thought).

> Anyway, after maybe 1000 miles of use I broke a rear NDS spoke at the *** during a ride, didn't notice it happen, wasn't because of a severe impact. ?I replaced it with a 14 gauge spoke of the same length and trued it back up. ?Now after a couple hundred additional miles I've found I've busted the replacement spoke.

> What the heck? ?I find it really peculiar that both breaks happened in the same spot. ?I'm not a great wheelbuilder but I've been building my own for many years and prior to this I'd never busted a spoke. ?The rim seemed fine while building it.

> Any advice much appreciated.

Assuming the ~drive-side spokes are evenly tensioned, and nothing
weird with the hub, I'd replace the rim.  (Is this spoke at or very
near the rim seam?)

... oh - tensioned by feel.  Get a tensiometer; it was a revelation
for me.

 
 
 

Busting the same spoke twice, what's going on?

Post by Dan » Sun, 07 Apr 2013 03:20:57


Quote:

> > Hey all,

> > I rebuilt some trusty old hubs with new rims and spokes (DA 7700 hubs, Sapim Race 14/15, Velocity A23 rims) using a cheapo truing stand and tensioning by feel but I'm decently skilled at this so the wheels turned out nicely (or so I thought).

> > Anyway, after maybe 1000 miles of use I broke a rear NDS spoke at the *** during a ride, didn't notice it happen, wasn't because of a severe impact. ?I replaced it with a 14 gauge spoke of the same length and trued it back up. ?Now after a couple hundred additional miles I've found I've busted the replacement spoke.

> > What the heck? ?I find it really peculiar that both breaks happened in the same spot. ?I'm not a great wheelbuilder but I've been building my own for many years and prior to this I'd never busted a spoke. ?The rim seemed fine while building it.

> > Any advice much appreciated.

> Assuming the ~drive-side spokes are evenly tensioned, and nothing
> weird with the hub, I'd replace the rim. ?(Is this spoke at or very
> near the rim seam?)

> ... oh - tensioned by feel. ?Get a tensiometer; it was a revelation
> for me.

... oh again - the replacement spoke was straight gauge and the rest
were butted?

 
 
 

Busting the same spoke twice, what's going on?

Post by retroguybi.. » Sun, 07 Apr 2013 03:30:23

I don't know the answer to your question, but as one who builds his own wheels I wish to thank you for starting this interesting thread. I am going to be following it. I haven't had this problem for many years (knock on wood!), but I do remember having it in the past.
 
 
 

Busting the same spoke twice, what's going on?

Post by thirty-si » Sun, 07 Apr 2013 03:37:25


Quote:
> Hey all,

> I rebuilt some trusty old hubs with new rims and spokes (DA 7700 hubs, Sapim Race 14/15, Velocity A23 rims) using a cheapo truing stand and tensioning by feel but I'm decently skilled at this so the wheels turned out nicely (or so I thought).

> Anyway, after maybe 1000 miles of use I broke a rear NDS spoke at the ***

If this is a trailing spoke, you possibly need to tighten up all the
trailing spokes and possibly ease all the leading spokes.  Check the
entry depth into the *** of leadin g and trailing spokes to see if
the error is obvious.    In future when tensioning up set initial
tension on all so that the threads just dissapear, then pull in all
the trailing spokes by 1/2 turn on the sprocket side and the realtive
balanced amount on the other.  .

Quote:
> during a ride, didn't notice it happen, wasn't because of a severe impact. ?I replaced it with a 14 gauge spoke of the same length and trued it back up. ?Now after a couple hundred additional miles I've found I've busted the replacement spoke.

> What the heck? ?I find it really peculiar that both breaks happened in the same spot. ?I'm not a great wheelbuilder but I've been building my own for many years and prior to this I'd never busted a spoke.

Your luck ran out!

Quote:
>?The rim seemed fine while building it.

It llikely was.

Quote:

> Any advice much appreciated.

when it rains, wear a hat.
 
 
 

Busting the same spoke twice, what's going on?

Post by thirty-si » Sun, 07 Apr 2013 03:39:25


Quote:


> > > Hey all,

> > > I rebuilt some trusty old hubs with new rims and spokes (DA 7700 hubs, Sapim Race 14/15, Velocity A23 rims) using a cheapo truing stand and tensioning by feel but I'm decently skilled at this so the wheels turned out nicely (or so I thought).

> > > Anyway, after maybe 1000 miles of use I broke a rear NDS spoke at the *** during a ride, didn't notice it happen, wasn't because of a severe impact. ?I replaced it with a 14 gauge spoke of the same length and trued it back up. ?Now after a couple hundred additional miles I've found I've busted the replacement spoke.

> > > What the heck? ?I find it really peculiar that both breaks happened in the same spot. ?I'm not a great wheelbuilder but I've been building my own for many years and prior to this I'd never busted a spoke. ?The rim seemed fine while building it.

> > > Any advice much appreciated.

> > Assuming the ~drive-side spokes are evenly tensioned, and nothing
> > weird with the hub, I'd replace the rim. ?(Is this spoke at or very
> > near the rim seam?)

> > ... oh - tensioned by feel. ?Get a tensiometer; it was a revelation
> > for me.

> ... oh again - the replacement spoke was straight gauge and the rest
> were butted?

maybe it was the weong oil  ;-)
 
 
 

Busting the same spoke twice, what's going on?

Post by datakol » Sun, 07 Apr 2013 03:50:50

2 ?

wash broken spokes with detergent then acetone CHOH thinner use a used toothbrush and glove(s)

then look at spokes under bright light with magnifier glass (Walmart)

see cracks ? many ? near the elbow ?

if you see many and appear deep then the whole lot is cracked  requiring replacement

check flanges for wear.

when going back together lube hub holes/spoke head with Finish Line Teflon/Wax.maybe file rough edges smooth.

 
 
 

Busting the same spoke twice, what's going on?

Post by Jay Beatti » Sun, 07 Apr 2013 06:33:01


Quote:
> Hey all,

> I rebuilt some trusty old hubs with new rims and spokes (DA 7700 hubs, Sapim Race 14/15, Velocity A23 rims) using a cheapo truing stand and tensioning by feel but I'm decently skilled at this so the wheels turned out nicely (or so I thought).

> Anyway, after maybe 1000 miles of use I broke a rear NDS spoke at the *** during a ride, didn't notice it happen, wasn't because of a severe impact. ?I replaced it with a 14 gauge spoke of the same length and trued it back up. ?Now after a couple hundred additional miles I've found I've busted the replacement spoke.

> What the heck? ?I find it really peculiar that both breaks happened in the same spot. ?I'm not a great wheelbuilder but I've been building my own for many years and prior to this I'd never busted a spoke. ?The rim seemed fine while building it.

> Any advice much appreciated.

I assume that you properly laced the wheel and did not lace the left
hand spokes in to the right hand holes.  That can create a really
acute angle and stress on the threaded end of the spoke.  I've broken
spokes at the *** end when I didn't bed them in or make any effort
to adjust the angle -- and generally when I under-tensioned the wheel
which allowed more spoke movement.  So do your stress relief and side
load to bed in the spokes and wind them up to tension -- 100kgf.  If
you don't have a tensiometer, go squeeze another good rear wheel for
reference.

Why you have a problem at just one spoke hole is a mystery.  Is the
spoke hole out of line with the other spoke holes, or is the ***
off angle compared to the other ***s?  The only explanation I can
think of is that the *** is bad (I assume that you re-used the same
14g ***), or there is a problem with the drilling that causes the
*** to be at an even harder angle to the spoke, or the rim has a
high spot, and the spoke is over-loaded.  But you would probably feel
that building the wheel, and in fact, you would probably be rounding
off the *** to put enough tension on the spoke to break it.

Other possibilities are: (1) bad luck, (2) demonic possession, and (3)
vandals.  In that order.  My $.02.

-- Jay Beattie.

 
 
 

Busting the same spoke twice, what's going on?

Post by Frank Krygowsk » Sun, 07 Apr 2013 09:37:11


Quote:

> Why you have a problem at just one spoke hole is a mystery. ?Is the
> spoke hole out of line with the other spoke holes, or is the ***
> off angle compared to the other ***s? ?The only explanation I can
> think of is that the *** is bad (I assume that you re-used the same
> 14g ***), or there is a problem with the drilling that causes the
> *** to be at an even harder angle to the spoke, or the rim has a
> high spot, and the spoke is over-loaded. ?But you would probably feel
> that building the wheel, and in fact, you would probably be rounding
> off the *** to put enough tension on the spoke to break it.

The above sounds reasonable to me too, especially the possibilities of
a mis-aligned or otherwise bad ***.  I'd certainly replace that
*** this time.

Do the ***s align well with the spoke directions?  Is that
particular *** bending the spoke where it exits the ***?  When
it's laced up, does plucking that spoke like a guitar string give a
markedly different tone than the rest?

- Frank Krygowski

 
 
 

Busting the same spoke twice, what's going on?

Post by Dan » Sun, 07 Apr 2013 10:20:25


Quote:

> > Why you have a problem at just one spoke hole is a mystery.  Is the
> > spoke hole out of line with the other spoke holes, or is the ***
> > off angle compared to the other ***s?  The only explanation I can
> > think of is that the *** is bad (I assume that you re-used the same
> > 14g ***), or there is a problem with the drilling that causes the
> > *** to be at an even harder angle to the spoke, or the rim has a
> > high spot, and the spoke is over-loaded.  But you would probably feel
> > that building the wheel, and in fact, you would probably be rounding
> > off the *** to put enough tension on the spoke to break it.

> The above sounds reasonable to me too, especially the possibilities of
> a mis-aligned or otherwise bad ***.  I'd certainly replace that
> *** this time.

Yeah, I considered the *** itself just for a second, but figured
he'd replaced the *** - especially if the spoke broke "at the
***".

(You could leave at least a *little* relevant context, you know.
They're just ASCII bits.)

Quote:
> Do the ***s align well with the spoke directions?  Is that
> particular *** bending the spoke where it exits the ***?  When
> it's laced up, does plucking that spoke like a guitar string give a
> markedly different tone than the rest?

Well, if it was straight gauge and the rest were butted...

But anyway, yeah, it's a juicy mystery for the newsgroup.

 
 
 

Busting the same spoke twice, what's going on?

Post by datakol » Sun, 07 Apr 2013 10:45:51

are spokes coming from same package, same LBS, same MO ?
 
 
 

Busting the same spoke twice, what's going on?

Post by Jay Beatti » Sun, 07 Apr 2013 11:35:35


Quote:


> > > Why you have a problem at just one spoke hole is a mystery. ?Is the
> > > spoke hole out of line with the other spoke holes, or is the ***
> > > off angle compared to the other ***s? ?The only explanation I can
> > > think of is that the *** is bad (I assume that you re-used the same
> > > 14g ***), or there is a problem with the drilling that causes the
> > > *** to be at an even harder angle to the spoke, or the rim has a
> > > high spot, and the spoke is over-loaded. ?But you would probably feel
> > > that building the wheel, and in fact, you would probably be rounding
> > > off the *** to put enough tension on the spoke to break it.

> > The above sounds reasonable to me too, especially the possibilities of
> > a mis-aligned or otherwise bad ***. ?I'd certainly replace that
> > *** this time.

> Yeah, I considered the *** itself just for a second, but figured
> he'd replaced the *** - especially if the spoke broke "at the
> ***".

Good point.  Maybe Dave can fill us in on whether it was a new ***.

-- Jay Beattie.

 
 
 

Busting the same spoke twice, what's going on?

Post by thirty-si » Sun, 07 Apr 2013 12:24:05


Quote:

> > Why you have a problem at just one spoke hole is a mystery. ?Is the
> > spoke hole out of line with the other spoke holes, or is the ***
> > off angle compared to the other ***s? ?The only explanation I can
> > think of is that the *** is bad (I assume that you re-used the same
> > 14g ***), or there is a problem with the drilling that causes the
> > *** to be at an even harder angle to the spoke, or the rim has a
> > high spot, and the spoke is over-loaded. ?But you would probably feel
> > that building the wheel, and in fact, you would probably be rounding
> > off the *** to put enough tension on the spoke to break it.

> The above sounds reasonable to me too, especially the possibilities of
> a mis-aligned or otherwise bad ***. ?I'd certainly replace that
> *** this time.

and when that doen't work, replace the rim?
flippin monkey response.
Use a friggin straight edge.
If there is a specific error on this one spoke and *** then the
*** seat MAY need adjustment (the use of a tapered punch to lever
or open an eyelet is simple), but I still feel it is likely that there
has been a trailing of the rim through unbalanced tensioning  by
winding in the leading spokes a tad more.  That would be the larger
error in any case and would still require correction.

Quote:

> Do the ***s align well with the spoke directions? ?Is that
> particular *** bending the spoke where it exits the ***? ?When
> it's laced up, does plucking that spoke like a guitar string give a
> markedly different tone than the rest?

http://SportToday.org/
 
 
 

Busting the same spoke twice, what's going on?

Post by datakol » Sun, 07 Apr 2013 20:49:16

YEAH that's the Chevy Method. Doahn start ? replace starter then work back from there replacing everything with new parts until it starts.
 
 
 

Busting the same spoke twice, what's going on?

Post by datakol » Sun, 07 Apr 2013 21:49:51

Quote:

> YEAH that's the Chevy Method. Doahn start ? replace starter then work back from there replacing everything with new parts until it starts.

zzzzzzzzzzz

off course, izzit the same spoke ?  

sooooooo, tellus how you marked the spoke hole ...

Icy, you always mark your spoke holes ?

When did you begin this procedure ?

are there witnesses we could interview ?