Spoke tension
joseph.sa...@gmail.com
I am going to build up some wheels for my soon to be good-weather daily
rider. I have only built a few wheels before, and that was a rim
replacement type deal that was pretty straight forward. These wheels
are supposed to last, and I want to do it right. I've read the various
online references, but spoke tension is still not clear to me.
NOS Ambrosio 36 hole Synthesis rims, Gipiemme Special Pista hubs. I
have not decided upon spokes yet, but they are all going to be 302mm. I
weigh 215lbs and the roads are rough. Should I bother getting one of
those Park tensionometers, and if I do, what should it say?
Thanks!
Joseph
bill
(Ebay auction)
Frankly, I think you'd probably get better results with the current
Mavic tubular rim. I was amazed at how much more durable they are
compared to all my old rims, including GP-4, "new" GP-4 etc. About the
only old rim I have that seems to be really durable is a Camagnolo
victory, but I only have a front wheel with that rim. My brother still
rides a set of old Mavic SSC rims among others. They were pretty
amazing in their day.
I don't remember that particular Ambrosio or when they were made, or
their weight. You really need to know that before choosing the spokes.
Then again in the old days everything was 14 gage and tight.
joseph.sa...@gmail.com
bill wrote:
> joseph.sa...@gmail.com wrote:
> > Hi All,
> >
> > I am going to build up some wheels for my soon to be good-weather daily
> > rider. I have only built a few wheels before, and that was a rim
> > replacement type deal that was pretty straight forward. These wheels
> > are supposed to last, and I want to do it right. I've read the various
> > online references, but spoke tension is still not clear to me.
> >
> > NOS Ambrosio 36 hole Synthesis rims, Gipiemme Special Pista hubs. I
> > have not decided upon spokes yet, but they are all going to be 302mm. I
> > weigh 215lbs and the roads are rough. Should I bother getting one of
> > those Park tensionometers, and if I do, what should it say?
> \
>
> http://tinyurl.com/yavz9b
>
> (Ebay auction)
>
Nice, but I need track hubs.
> Frankly, I think you'd probably get better results with the current
> Mavic tubular rim. I was amazed at how much more durable they are
> compared to all my old rims, including GP-4, "new" GP-4 etc. About the
> only old rim I have that seems to be really durable is a Camagnolo
> victory, but I only have a front wheel with that rim. My brother still
> rides a set of old Mavic SSC rims among others. They were pretty
> amazing in their day.
This bike is a vintage one, so I am trying to keep it mostly period (at
least for high-visibility items). Plus I like the shiny sliver finish
never marred by a brake shoe!
I had some 32 hole Victory Crono's once that I pulled about 10 eyelets
out of on a big hill stomp once. I also have some Record Strada's that
have been to hell and back with no problems. I also had some GL280's
that seemed to handle more than I could dish out. But I have never used
any modern tubular rims. I suppose they are better as a whole, but
again, I need period!
> I don't remember that particular Ambrosio or when they were made, or
> their weight. You really need to know that before choosing the spokes.
> Then again in the old days everything was 14 gage and tight.
The Synthesis is allegedly a super strong rim. With 36 double eyelets
and 430 grams each I should hope they are strong! 70's-80's I believe.
While vinatge, this is to be a daily rider, so I am open to all spoke
suggestions, and other practical things like sealed bb, etc are
probably going to be used. So should I go with 14 ga straight, or
butted?
Joseph
Art Harris
> The Synthesis is allegedly a super strong rim. With 36 double eyelets
> and 430 grams each I should hope they are strong! 70's-80's I believe.
>
> While vinatge, this is to be a daily rider, so I am open to all spoke
> suggestions, and other practical things like sealed bb, etc are
> probably going to be used. So should I go with 14 ga straight, or
> butted?
Butted spokes will make a more durable wheel (less likely for spokes to
go slack). As for tension, follow the advice in The Bicycle Wheel:
Tighten the spokes until squeezing pairs of spokes all around the wheel
causes the wheel to develop a slight wavy shape. Then back off about 1
turn on all spokes.
Art Harris
bill
joseph.sa...@gmail.com wrote:
>
> This bike is a vintage one, so I am trying to keep it mostly period (at
> least for high-visibility items). Plus I like the shiny sliver finish
> never marred by a brake shoe!
OK ok I understand. (Actually I buy the least expensive version of the
contemporary Mavic, which is all silver).
>
> I had some 32 hole Victory Crono's once that I pulled about 10 eyelets
> out of on a big hill stomp once. I also have some Record Strada's that
> have been to hell and back with no problems. I also had some GL280's
> that seemed to handle more than I could dish out. But I have never used
> any modern tubular rims. I suppose they are better as a whole, but
> again, I need period!
I have some 280 and 330 NOS in my bag of tricks. They are so light.
SNIP
>
> The Synthesis is allegedly a super strong rim. With 36 double eyelets
> and 430 grams each I should hope they are strong! 70's-80's I believe.
That sounds pretty substantial to me. I think the GP4 was 400.
>
> While vinatge, this is to be a daily rider, so I am open to all spoke
> suggestions, and other practical things like sealed bb, etc are
> probably going to be used. So should I go with 14 ga straight, or
> butted?
I've built both ways. I've built probably 2 dozen pairs of wheels in my
life. My biggest problem always seems to be fatigue. Even if you do
all the "right things" with avoiding spoke windup, "stress-relieving,"
spoke alignment etc, it seems there are always new problems to crop up.
Not every wheelset--but from time to time.
Without a doubt, the 14 ga straights are easier to true and less apt to
go pretzel when a spoke breaks. Yet the theory tends to be behind the
14/15. I've even built a wheel with different gages left and right on
a rear wheel (my current one is 15/16 left and 14/15 right. It seems to
balance the spoke stress. Next time I'll make the right side straight
gage so that all the nipples are the same!). I think 15/16 is probably
too light for a rim that heavy. This isn't from any calcs--just from
experience of what seems reasonable.
14 gage straight are more available.
I've always fatigued at the elbow or at a nick somewhere, I've never
failed at the nipple end of the spoke. It seems to me that looking over
the problem wheels, these elbow failures are often possibly caused when
the spoke touches the flange as well as the hole. In other words only
the outside spokes. There must be a big bending moment developing in
that span due to the cross at midlength or something. There must be a
way to defet this problem, and on most of my wheels it hasn't happened.
) That's what my last problem wheel exhibited. I can't remember for
sure if I've fatigued inside spokes as well. Probably.
The other thing I've fatigued are the rims in way of the holes--on
non-eyelet rims. But yours are full eyelet so no problem hopefully.
Ozark Bicycle
IMO, 14/15ga in the rear, 15ga in the front.
And, IMO, do buy a Park tensiometer.
Qui si parla Campagnolo
Look for 90 to 100 kgf for these wheels, any wheel, AAMOF.Spoke gauge
doesn't matter, tension is tension.
Michael Press
<1163000787....@m7g2000cwm.googlegroups.com>,
joseph.sa...@gmail.com wrote:
Stainless steel double butted spokes, brass nipples. No
question about it.
Get a copy of a book called The_Bicycle_Wheel, by
Jobst Brandt. Read the building instructions through
before starting the build.
--
Michael Press
Michael Press
<1163006951.8...@e3g2000cwe.googlegroups.com>,
joseph.sa...@gmail.com wrote:
> While vinatge, this is to be a daily rider, so I am open to all spoke
> suggestions, and other practical things like sealed bb, etc are
> probably going to be used. So should I go with 14 ga straight, or
> butted?
Butted.
--
Michael Press
joseph.sa...@gmail.com
I'm also going to get a good spoke wrench instead of the nipple-killer
I have now. But how do I know what size? The Park Tools web site says
they are color coded for easy id, but that doesn't help me in my
ignorance.
Joseph
Qui si parla Campagnolo
Park black spoke wrench, use 14/15 , brass nipps all around, get the
Park Tensionometer, nice tool for your use. DT or Sapim spokes..
jim beam
> In article
> <1163000787....@m7g2000cwm.googlegroups.com>,
> joseph.sa...@gmail.com wrote:
>
>> Hi All,
>>
>> I am going to build up some wheels for my soon to be good-weather daily
>> rider. I have only built a few wheels before, and that was a rim
>> replacement type deal that was pretty straight forward. These wheels
>> are supposed to last, and I want to do it right. I've read the various
>> online references, but spoke tension is still not clear to me.
>>
>> NOS Ambrosio 36 hole Synthesis rims, Gipiemme Special Pista hubs. I
>> have not decided upon spokes yet, but they are all going to be 302mm. I
>> weigh 215lbs and the roads are rough. Should I bother getting one of
>> those Park tensionometers, and if I do, what should it say?
>
> Stainless steel double butted spokes, brass nipples. No
> question about it.
make that "branded" stainless steel. there's plenty of unbranded stuff
out there that's stainless and it doesn't last.
>
> Get a copy of a book called The_Bicycle_Wheel, by
> Jobst Brandt. Read the building instructions through
> before starting the build.
>
to the o.p., that book will tell you how to build a wheel, but be
careful about some of its content. for instance, ignore the bit about
tension as high as the rim can bear - it's too high and it'll give
increased likelihood of rim taco and cause rim cracking. use a
tensiometer with the tensions peter gave you. and if you want to have
the rim hole line up with the hub label, read the gerd schraner book -
it tells you how to do it - the brandt book doesn't.
be very careful with the brandt materials theory bit too - that's /way/
messed up.
joseph.sa...@gmail.com
Hi Everybody,
Thanks for all the input.
I just ordered a black Park wrench, the Park tension meter, and 75 DT
Competition double butted spokes with brass nipples. The LBS didn't
have any of that stuff! I'll do the lacing at home, and I can borrow
the good truing stand at the LBS for the final adjustments. I'll shoot
for 95 kgf rather than risking the taco effect. Particularly with such
(hopefully) strong rims, tightening until the rim is about to taco
doesn't sound wise to me. Particularly with my novice feel for how
things are developing.
Joseph
Ozark Bicycle
You might find this, written by Jim Langley, helpful:
Some of the info is dated (e.g., "Mavic makes the best rims"), but the
basics are sound.
jim beam
line" is questionable. as you can see in this pic,
http://www.flickr.com/photos/38636024@N00/104463818/
the hub holes deform during the build. "correcting the spoke line"
before this process has occurred is premature and will leave the spoke
elbow with the wrong resultant angle. the spoke elbow comes pre-formed
with the best resultant angle and the hub flange is canted and drilled
also to give the best resultant angle. it may look odd when first
laced, but when fully tensioned, the net result is optimized. i
therefore say leave the spoke elbow angle alone - do /not/ bend.
bill
jim beam wrote:
>
> http://www.flickr.com/photos/38636024@N00/104463818/
>
> the hub holes deform during the build. "correcting the spoke line"
> before this process has occurred is premature and will leave the spoke
> elbow with the wrong resultant angle. the spoke elbow comes pre-formed
> with the best resultant angle and the hub flange is canted and drilled
> also to give the best resultant angle. it may look odd when first
> laced, but when fully tensioned, the net result is optimized. i
> therefore say leave the spoke elbow angle alone - do /not/ bend.
I wonder how long it takes to get that way. I've always noticed this
too, but I've never loosened and examined a new wheel to see how much
of that plastic forming takes place before it is even riddenn
Ozark Bicycle
I agree; I do not do that, although many builders do. At the very
least, it seems unnecessary.
That said, I think the Langley article can be useful to a beginner; he
writes pretty clearly and the pictures are instructive.
ajam...@hotmail.com
Personally I've always been of the opinion that bending the elbow
beyond the point required and then back to the correct position was the
way to go. The theory was the it would help remove the residual bending
stress in the spoke and make it conform better to different hub flange
shapes.
Since my wheels last my way must be correct..
Back to the OP .. just do it.. the only thing you can really screw up
is to over tighten. If your not happy do it again... and again and
again.
Everyone who has ever built a wheel had to build their first wheel at
some point... I would like to give the whole wheel building as a zen
exercise speach but it only really works live, (for best results add a
beer).
Jay Beattie
<joseph.sa...@gmail.com> wrote in message
news:1163081518....@b28g2000cwb.googlegroups.com...
I don't think there is any risk of a taco effect below 130 kgf
based on my experience, not on a 425 gram rim 36 hole rim. In
fact, I doubt you will be able to keep these rims true under
about 110 kgf at your weight without some sort of thread locker
(which I prefer not to use). I am 215lbs and ride 32 hole
Velocity Aeroheads (400 gram clincher). I have to run over 110
kgf just to keep them true. Same goes with my Open Pro rims. YMMV
with a track wheel where the tensions are more balanced, but on a
road wheel, 95kgf would not cut it for me. -- Jay Beattie.
jobst....@stanfordalumni.org
http://www.flickr.com/photos/38636024@N00/104463818/
> much of that plastic forming takes place before it is even ridden.
It happens immediately when a spoke is tensioned as the flange
conforms to the shape of the spoke elbow which remains unchanged from
tensioning. Unspoking a tensioned wheel that has not been ridden
shows the spoke seating effect in its final condition. In use, spokes
do not increase in tension so there is no further deformation of
flange holes.
The spoke line is best improved manually without the hazard of
damaging flanges by hammering. This is more apparent with large
flange hubs. Not improving the spoke line leaves spokes with higher
residual stress that is not easily removed otherwise. That is the
purpose of this step. That spokes do not lie flat against the flange
is apparent after tensioning and should be corrected.
Jobst Brandt
Art Harris
> I don't think there is any risk of a taco effect below 130 kgf
> based on my experience, not on a 425 gram rim 36 hole rim. In
> fact, I doubt you will be able to keep these rims true under
> about 110 kgf at your weight without some sort of thread locker
> (which I prefer not to use). I am 215lbs and ride 32 hole
> Velocity Aeroheads (400 gram clincher). I have to run over 110
> kgf just to keep them true. Same goes with my Open Pro rims. YMMV
> with a track wheel where the tensions are more balanced, but on a
> road wheel, 95kgf would not cut it for me. -- Jay Beattie.
Remember that 36 spokes puts more total tension on the wheel than 32.
Regardless, my experience with 36-spoke wheels is that if the wheel
stays true after stress relieving, it's not going to taco. I've built
lots of wheels, never used a Tensiometer, and never tacoed a wheel.
Also to the OP: You said you're using Gipiemme Special Pista hubs. Are
these going to be track wheels with a fixed gear in the back? If so,
the minimal dish will make it easier to keep the wheel true.
Art Harris
Tosspot
> jim beam wrote:
<snip>
> Everyone who has ever built a wheel had to build their first wheel at
> some point... I would like to give the whole wheel building as a zen
> exercise speach but it only really works live, (for best results add a
> beer).
Beer 1: Right, a basic 3x, that's the idea.
Beer 2: Radial, the way to go, even it is a rear disc, it'll be ok.
Beer 3: You know, 2 leading two trailing looks much nicer.
Beer 4: Crows Foot! However could I have dreamed of anything else!
Beer 5: Sod this crossing lark. The Citreon Monospoke!
http://www.sheldonbrown.com/nanodrive/index.html
Qui si parla Campagnolo
After lacing, with no tension, I push or pull on each spoke at the
flange to make sure they lie as flat as possible against the flange
before tensioning. If ya don't, and tension the wheel, THEN push on the
spoke to have it lie against the flange, it changes(reduces) the
tension by a lot.
Jay Beattie
"Art Harris" <n2...@hotmail.com> wrote in message
news:1163095693.0...@e3g2000cwe.googlegroups.com...
BTW, the quality (maintaining true) of my wheels dumped after I
started using a tensiometer a few years ago -- probably because I
tried to achieve a perfect 100kgf tension, which by feel, is not
all that tight. If I twist the spokes up to my perfect
good-old-days-feel-o-meter tension, I was getting readings in the
120-130kgf range, which may cause cracks in "modern" rims. I
found by trial and error that even on a 36 hole OC rim, I needed
tension in the 110kgf range, which was the lowest I could go
without the wheel going out of true. That is for a 400-450 gram
rim. I probably could get away with a lower tension on a heavier
rim, which is what I am going to build next for my commuter.
Like you say, the tension disparity in a track wheel is not so
great, and they can take a lower tension (assuming a reasonably
stout rim). Joseph should try out 95kgf and see what happens --
and not feel like a failure if his wheel goes slack, and he needs
to increase the tension. -- Jay Beattie.
bill
I have never measured the tension (or should I say more precisely the
deflection) of any spokes of any of my wheels.
Apparently the basic parameters are sort of engineered into the size of
the available pieces, and the craft takes care of the rest.
jobst....@stanfordalumni.org
> After lacing, with no tension, I push or pull on each spoke at the
> flange to make sure they lie as flat as possible against the flange
> before tensioning. If ya don't, and tension the wheel, THEN push on
> the spoke to have it lie against the flange, it changes(reduces) the
> tension by a lot.
I think you should look at cosine error. For such small angles the
length of the spoke changes (cos(1°)=0.999847695) not at all, and
therefore, cannot affect tension.
Jobst Brandt
joseph.sa...@gmail.com
My real bike has Velocity Aerohead/OC 36 with 14/15 spokes. The tension
is if I recall about 90 kgf. These wheels have been great. When I get
the tension meter I'll check them. I'm only 215 now but have been more
in the past, and these wheels have not needed any truing since new
7,000km ago.
Joseph
joseph.sa...@gmail.com
These are used hubs that show these flange deformations. The rear hub
seems to only ever have been built up one way, while the front seems to
have been used more than one way. I assume it would be best for me to
assemble the rear wheel to match this deformation, but what about the
front wheel? Does it really make any difference? These are low flange
hubs and low profile rims, so the spoke angle is about as shallow as it
is going to get on a front wheel.
Joseph
jobst....@stanfordalumni.org
http://www.flickr.com/photos/38636024@N00/104463818/
> These are used hubs that show these flange deformations. The rear
> hub seems to only ever have been built up one way, while the front
> seems to have been used more than one way. I assume it would be best
> for me to assemble the rear wheel to match this deformation, but
> what about the front wheel? Does it really make any difference?
> These are low flange hubs and low profile rims, so the spoke angle
> is about as shallow as it is going to get on a front wheel.
The more tangent the spokes emanate form the flange the less
probability exists for flange failure. I have samples of low flange
36 hole rear hubs where a pair of spokes ripped out of the flange.
I haven't experienced any flange failures but hear of them now and
then. Try tho lace the wheel so that the spokes sit in the same dents
and choose the deepest set if there is one.
Jobst Brandt
Mark Hickey
I don't doubt your calculations, but have noticed (and I'm guessing
this is what Peter saw that led him to the conclusion) is that bending
the spoke elbows has a very noticeable effect on the "tension" when
you're first lacing up a wheel. That is, if you screw all the nipples
to "snug" and then bend the elbows, the nipples will all be noticeably
loose. I wouldn't think that the difference between this mode and a
fully-tensioned spoke would be so great, but am far too lazy to test
the theory. ;-)
Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame
jobst....@stanfordalumni.org
>>> After lacing, with no tension, I push or pull on each spoke at the
>>> flange to make sure they lie as flat as possible against the
>>> flange before tensioning. If ya don't, and tension the wheel, THEN
>>> push on the spoke to have it lie against the flange, it
>>> changes(reduces) the tension by a lot.
>> I think you should look at cosine error. For such small angles the
>> length of the spoke changes (cos(1°)=0.999847695) not at all, and
>> therefore, cannot affect tension.
> I don't doubt your calculations, but have noticed (and I'm guessing
> this is what Peter saw that led him to the conclusion) is that
> bending the spoke elbows has a very noticeable effect on the
> "tension" when you're first lacing up a wheel. That is, if you
> screw all the nipples to "snug" and then bend the elbows, the
> nipples will all be noticeably loose. I wouldn't think that the
> difference between this mode and a fully-tensioned spoke would be so
> great, but am far too lazy to test the theory.
Well he said it reduced spoke tension and if the wheel wasn't
tensioned it makes no difference to tension that isn't there. What
are you trying to infuse here?
Jobst Brandt
jim beam
what are you trying to deny here? you're also "forgetting" to
acknowledge the effect of hub hole deformation on spoke tension.
jim beam
> Bill Platt writes:
>
> http://www.flickr.com/photos/38636024@N00/104463818/
>
>>> the hub holes deform during the build. "correcting the spoke line"
>>> before this process has occurred is premature and will leave the
>>> spoke elbow with the wrong resultant angle. the spoke elbow comes
>>> pre-formed with the best resultant angle and the hub flange is
>>> canted and drilled also to give the best resultant angle. it may
>>> look odd when first laced, but when fully tensioned, the net result
>>> is optimized. i therefore say leave the spoke elbow angle alone -
>>> do /not/ bend.
>
>> I wonder how long it takes to get that way. I've always noticed this
>> too, but I've never loosened and examined a new wheel to see how
>> much of that plastic forming takes place before it is even ridden.
>
> It happens immediately when a spoke is tensioned as the flange
> conforms to the shape of the spoke elbow which remains unchanged from
> tensioning. Unspoking a tensioned wheel that has not been ridden
> shows the spoke seating effect in its final condition. In use, spokes
> do not increase in tension so there is no further deformation of
> flange holes.
bullshit. ride a fully tensioned wheel that has not been "stress
relieved". inside one block, that wheel is like a dog's hind leg and
multiple spokes are loose. if you won't acknowledge that as evidence of
continuing hub hole deformation and increasing spoke tension in use,
you're stupid as well as stubborn.
>
> The spoke line is best improved manually without the hazard of
> damaging flanges by hammering. This is more apparent with large
> flange hubs. Not improving the spoke line leaves spokes with higher
> residual stress
prove it. a stress corrosion test costs virtually nothing. do it.
> that is not easily removed otherwise. That is the
> purpose of this step. That spokes do not lie flat against the flange
> is apparent after tensioning and should be corrected.
except when the hub holes have been deformed, in which case, "correcting
the spoke line" is both unnecessary and premature. spoke manufacturers
know /way/ more about their product than you do and /they/ say not to
bend the spoke. /you/ don't even know the difference between spokes
that are swaged or drawn, so how are you qualified to speculate on
residual stress?
jim beam
not really unless you plan on these hubs being ultra-high mileage,
loaded touring, etc.
> These are low flange
> hubs and low profile rims, so the spoke angle is about as shallow as it
> is going to get on a front wheel.
use the "mavic" method of seating the spokes into the hub flanges - grip
the rim at opposite sides when laced and press the hub with your near
full body weight into a block of wood. this way, you can seat spokes
without having to bring them to tension first, hence avoiding this
bending business. the mavic pdf's on wheel building were on the mavic
tech web site last time i looked.
jim beam
well, the less the effect of radial tension...
> I have samples of low flange
> 36 hole rear hubs where a pair of spokes ripped out of the flange.
ok, but how is that related to the above?
> I haven't experienced any flange failures but hear of them now and
> then.
ok, but are you correlating that with the above, or is this just waffle?
> Try tho lace the wheel so that the spokes sit in the same dents
> and choose the deepest set if there is one.
because?
[answer: the hub hole indents, when re-loaded perpendicular, can
initiate fatigue. but in reality, because the indent follows the spoke
radius, which is real close to the original hole radius, the effect is
negligible for normal use and can be safely ignored. if the aesthetics
aren't a concern.]
jim beam
the factory tension on my mavic cosmos. if you don't like commercial
thread lock, use linseed oil.
joseph.sa...@gmail.com
120-160 miles per week with fully loaded weight of about 240 lbs. This
is for my good-weather commuter. If the hubs break, I supose I'll just
buy new ones, right?
> > These are low flange
> > hubs and low profile rims, so the spoke angle is about as shallow as it
> > is going to get on a front wheel.
>
> use the "mavic" method of seating the spokes into the hub flanges - grip
> the rim at opposite sides when laced and press the hub with your near
> full body weight into a block of wood. this way, you can seat spokes
> without having to bring them to tension first, hence avoiding this
> bending business. the mavic pdf's on wheel building were on the mavic
> tech web site last time i looked.
I like that idea.
Joseph
Ben C
> Jay Beattie wrote:
>> "Art Harris" <n2...@hotmail.com> wrote in message
>> BTW, the quality (maintaining true) of my wheels dumped after I
>> started using a tensiometer a few years ago -- probably because I
>> tried to achieve a perfect 100kgf tension, which by feel, is not
>> all that tight. If I twist the spokes up to my perfect
>> good-old-days-feel-o-meter tension, I was getting readings in the
>> 120-130kgf range, which may cause cracks in "modern" rims. I
>> found by trial and error that even on a 36 hole OC rim, I needed
>> tension in the 110kgf range, which was the lowest I could go
>> without the wheel going out of true. That is for a 400-450 gram
>> rim. I probably could get away with a lower tension on a heavier
>> rim, which is what I am going to build next for my commuter.
>> Like you say, the tension disparity in a track wheel is not so
>> great, and they can take a lower tension (assuming a reasonably
>> stout rim). Joseph should try out 95kgf and see what happens --
>> and not feel like a failure if his wheel goes slack, and he needs
>> to increase the tension. -- Jay Beattie.
>>
>>
> or use thread lock. it works and allows my wheels to stay true at 900N,
> the factory tension on my mavic cosmos. if you don't like commercial
> thread lock, use linseed oil.
So does linseed oil actually lock the threads? I thought it was just to
lubricate them a bit and provide a corrosion barrier.
Sheldon Brown recommends using a light grease or oil, but says to use no
oil on the non-drive side of a rear wheel to reduce the chance of the
nipples coming undone.
Although in principle it shouldn't be the drag of unlubricated threads
that keeps them from coming undone, but the compression of them being
(even only slightly) tight.
Mark Hickey
>On 2006-11-10, jim beam <spamv...@bad.example.net> wrote:
>> or use thread lock. it works and allows my wheels to stay true at 900N,
>> the factory tension on my mavic cosmos. if you don't like commercial
>> thread lock, use linseed oil.
>
>So does linseed oil actually lock the threads? I thought it was just to
>lubricate them a bit and provide a corrosion barrier.
It does dry "tacky"... I think "lock" is a stretch, but it could help
if (for whatever reason) a spoke does manage to go slack.
>Sheldon Brown recommends using a light grease or oil, but says to use no
>oil on the non-drive side of a rear wheel to reduce the chance of the
>nipples coming undone.
Or you could just use alloy nipples and ride along the ocean (that'll
sometimes keep them coming loose, even with a spoke wrench). ;-)
>Although in principle it shouldn't be the drag of unlubricated threads
>that keeps them from coming undone, but the compression of them being
>(even only slightly) tight.
In principle, spokes in a properly built wheel never go slack, but I
don't have any problem believing that using linseed oil will help
prevent the nipple from turning if the spoke does go slack (whether
from inadequate build tension or hitting a really large object).
Mark Hickey
I'm saying nothing more than bending the spokes seems to slacken very
low-tension spokes, and that I'm surprised that there's no effect on
highly-tensioned spokes as well.
Peter Cole
> use the "mavic" method of seating the spokes into the hub flanges - grip
> the rim at opposite sides when laced and press the hub with your near
> full body weight into a block of wood. this way, you can seat spokes
> without having to bring them to tension first, hence avoiding this
> bending business. the mavic pdf's on wheel building were on the mavic
> tech web site last time i looked.
Can't find it -- link?
Qui si parla Campagnolo
Lost in translation. Good spoke alignment, from the hub to the rim is
important. Anything you can do to make ths happen on a finished wheel
is a good thing. Tension alone does not take the bend out of the spoke
at the flange.
Peter Cole
> the hub holes deform during the build. "correcting the spoke line"
> before this process has occurred is premature and will leave the spoke
> elbow with the wrong resultant angle. the spoke elbow comes pre-formed
> with the best resultant angle and the hub flange is canted and drilled
> also to give the best resultant angle. it may look odd when first
> laced, but when fully tensioned, the net result is optimized. i
> therefore say leave the spoke elbow angle alone - do /not/ bend.
This is good news. The only problem I seem to have is that the spokes
and hubs I have don't seem to have the inbound and outbound parts
labeled. Is there some secret code?
Peter Cole
> except when the hub holes have been deformed, in which case, "correcting
> the spoke line" is both unnecessary and premature. spoke manufacturers
> know /way/ more about their product than you do and /they/ say not to
> bend the spoke.
From the Sapim "FAQ"
"Is it possible to replace 1 or 2 spokes or do you have to replace all
the spokes and re-spoke the wheel?
If you do not re-spoke the wheel, the replaced spokes will have to be
very tightly tensioned if the wheel is to be round and true.
Do not forget when the first spoke breaks, all the other spokes suddenly
have a different tension pattern! Also the rim structure goes out of line.
If you only replace 1 or 2 spokes, you can expect these or the spokes
next to them to break again. It is best to re-spoke the entire wheel and
to replace the hub just in case the hub holes are damaged. It is
possible to re-use the hub by mounting the spokes in the opposite
direction (i.e. not in the direction of the ovalisation of the hub holes)."
Glad I read this! The next time I break a spoke, I'll replace them all
and the hub! As a matter of fact, perhaps I should replace all my spokes
and hubs now, just in case!
Ozark Bicycle
When wet, it lubes the spoke threads. When it dries, it provides a
gentle thread lock.
dvt
I've been watching this thread, hoping that I wasn't the only one with
this question. How do you "cant and drill" a hole in the hub flange so
that both inbound *and* outbound spokes are "optimized?" If the hole was
so canted, would that mean that the hubs should not be deformed during
the build?
--
Dave
dvt at psu dot edu
Everyone confesses that exertion which brings out all the powers of body
and mind is the best thing for us; but most people do all they can to
get rid of it, and as a general rule nobody does much more than
circumstances drive them to do. -Harriet Beecher Stowe, abolitionist and
novelist (1811-1896)
bill
dvt wrote:
> Peter Cole wrote:
SNIP
> >
> > This is good news. The only problem I seem to have is that the spokes
> > and hubs I have don't seem to have the inbound and outbound parts
> > labeled. Is there some secret code?
>
> I've been watching this thread, hoping that I wasn't the only one with
> this question. How do you "cant and drill" a hole in the hub flange so
> that both inbound *and* outbound spokes are "optimized?" If the hole was
> so canted, would that mean that the hubs should not be deformed during
> the build?
I think with the exception of weird special purpose hubs, all the holes
are the same. There is no cant. The spoke is bent into a J to take care
of that. The holes are all drilled parallel to the hub axis. The edges
of the holes are chamfered, but as noted upthread, the spokes seat into
the hub and create additional indentations.
Michael Press
<slrnel8kn7....@bowser.marioworld>,
Ben C <spam...@spam.eggs> wrote:
Spoke nipples unscrew when the spoke does not have
enough tension applied. Spoke nipples remain in place
when the wheel is built with sufficient tension in the
spokes. As the spoke reaches the contact patch the
tension decreases, then increases again. On bumps, the
tension is temporarily reduced further. Should the
wheel be built with insufficient tension, the lowered
tension during the duty cycle can reduce tension to
zero, allowing the spoke nipple to unwind.
--
Michael Press
Michael Press
<fMudnYCGSeho4MnY...@comcast.com>,
Peter Cole <peter...@comcast.net> wrote:
Good one. However, you gave yourself away when you said
`secret code'.
--
Michael Press
bill
Michael Press wrote:
SNIP
>
> Spoke nipples unscrew when the spoke does not have
> enough tension applied. Spoke nipples remain in place
> when the wheel is built with sufficient tension in the
> spokes. As the spoke reaches the contact patch the
> tension decreases, then increases again. On bumps, the
> tension is temporarily reduced further. Should the
> wheel be built with insufficient tension, the lowered
> tension during the duty cycle can reduce tension to
> zero, allowing the spoke nipple to unwind.
But the unwinding must overcome the latent torque required of the
threads. So if you use galvanized spokes (or is it zinc plated) like we
used to do, you never needed any threadlock. Stainless is sort of 50-50
they may unwind or not. Chrome-plated (are they still available?) were
very slippery with virtually no latent torque. I had one fall apart on
me as a kid! I built it with no threadlock.
Another thing: If you don't make sure to prevent the spokes from
twisting from the torque, that will leave a force available to unwind
the nipples! Just overshoot a bit when you turn the wrench and then
turn back. So a 1/4 turn is 1/2-1/4. My first lesson in wheelbuilding
had this ritual of placing the wheel on the ground, resting on its
axle, and pushing the rim. You'd hear all sorts of sounds. It was the
spokes unwinding. Better to prevent them from winding in the first
place!
Sheldon Brown
> > So does linseed oil actually lock the threads?
> > I thought it was just to
> > lubricate them a bit and provide a corrosion barrier.
Ozark Bicycle replied:
> When wet, it lubes the spoke threads. When it dries, it provides a
> gentle thread lock.
Yep, this is a traditional technique, works very well...if you can
stand the smel!
Personally, I can't.
Sheldon "Yeccccch" Brown
+----------------------------------+
| Good health is nothing but the |
| slowest way to die. -Les Barker |
+----------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com
Ozark Bicycle
Sheldon Brown wrote:
> Ben C wrote:
>
> > > So does linseed oil actually lock the threads?
> > > I thought it was just to
> > > lubricate them a bit and provide a corrosion barrier.
>
> Ozark Bicycle replied:
>
> > When wet, it lubes the spoke threads. When it dries, it provides a
> > gentle thread lock.
>
> Yep, this is a traditional technique, works very well...if you can
> stand the smel!
>
When I began to use linseed oil in wheelbuilding ~20 years ago, I was
already appreciative of the smell from my woodworking stuff. YNMV.
And it does work well, at least as well as "Spoke Prep" and much more
realistically priced.
> Personally, I can't.
>
Jay Beattie
"Peter Cole" <peter...@comcast.net> wrote in message
news:Q4ednSFnZZd6HMnY...@comcast.com...
The sudden detensioning also causes great stress to the frame and
components, so if I break a spoke, I usually buy a whole new
bike. My clothes get stressed, too, so I usually buy a new
jersey and shorts. A vacation home would be good, too, yah, and
a new car and . . . -- Jay Beattie.
Ozark Bicycle
That's the modern bike biz, in a nutshell!
> My clothes get stressed, too, so I usually buy a new
> jersey and shorts.
Well, sure, ya don't want ride a hot new bike in those old duds.
Mark Hickey
>Another thing: If you don't make sure to prevent the spokes from
>twisting from the torque, that will leave a force available to unwind
>the nipples! Just overshoot a bit when you turn the wrench and then
>turn back. So a 1/4 turn is 1/2-1/4.
Better yet - simply make a swipe with a black marker on the spokes
above the nipples when you first lace up the wheel. You can easily
see how much they're twisting and simply over-rotate and reverse to
bring the mark back to its correct position. No pings (or perhaps a
couple very small ones) when you ride the wheel the first time.
Mark Hickey
> From the Sapim "FAQ"
>
>"Is it possible to replace 1 or 2 spokes or do you have to replace all
>the spokes and re-spoke the wheel?
>
>If you do not re-spoke the wheel, the replaced spokes will have to be
>very tightly tensioned if the wheel is to be round and true.
>Do not forget when the first spoke breaks, all the other spokes suddenly
>have a different tension pattern! Also the rim structure goes out of line.
>If you only replace 1 or 2 spokes, you can expect these or the spokes
>next to them to break again. It is best to re-spoke the entire wheel and
>to replace the hub just in case the hub holes are damaged. It is
>possible to re-use the hub by mounting the spokes in the opposite
>direction (i.e. not in the direction of the ovalisation of the hub holes)."
Heh heh heh - a great warning about taking spoke replacement advice
from a spoke manufacturer.
However, if you scratch the paint on your frame, it's clear that it
should be discarded immediately. ;-)
jobst....@stanfordalumni.org
Many hubs have slightly cup shaped flanges that approximate the angle
of the average spoke to the rim so that outbound spokes do not have so
hard a time of aligning to the angle. These flanges are drilled, one
hole at a time by an NC machine that indexes at the appropriate
interval as the angled drill penetrates the flange normal to its
surface.
When taking apart a wheel, the elbows of outbound spokes will have an
acute angle and inbound ones an obtuse angle. The obtuse angle is the
natural one from manufacture. The acute angle results from improving
the spoke line, as was discussed here and explained in "the Bicycle
Wheel". The angular difference is small but important. That is why
changing a rim should be done without removing spokes from the hub
while transferring them to the new rim, one at a time to prevent
getting acute angled spokes into inbound positions. These cannot be
improved in place.
Jobst Brandt
joseph.sa...@gmail.com
Just thinking about linseed oil smell gave me a warm fuzzy feeling when
it was first mentioned.
So does it go just on the threads, or should some also go on the nipple
shoulder?
Joseph
Ozark Bicycle
joseph.sa...@gmail.com wrote:
> Ozark Bicycle wrote:
> > Sheldon Brown wrote:
> > > Ben C wrote:
> > >
> > > > > So does linseed oil actually lock the threads?
> > > > > I thought it was just to
> > > > > lubricate them a bit and provide a corrosion barrier.
> > >
> > > Ozark Bicycle replied:
> > >
> > > > When wet, it lubes the spoke threads. When it dries, it provides a
> > > > gentle thread lock.
> > >
> > > Yep, this is a traditional technique, works very well...if you can
> > > stand the smel!
> > >
> >
> > When I began to use linseed oil in wheelbuilding ~20 years ago, I was
> > already appreciative of the smell from my woodworking stuff. YNMV.
> >
> > And it does work well, at least as well as "Spoke Prep" and much more
> > realistically priced.
> >
>
> Just thinking about linseed oil smell gave me a warm fuzzy feeling when
> it was first mentioned.
>
Is this from woodworking/refinishing experience?
> So does it go just on the threads, or should some also go on the nipple
> shoulder?
>
I just put it on the threads.
And your workspace will be filled with the smell of linseed oil! :-)
diann...@yahoo.com
> > holes are the same. There is no cant. The spoke is bent into a J
> > to take care of that. The holes are all drilled parallel to the hub
> > axis. The edges of the holes are chamfered, but as noted upthread,
> > the spokes seat into the hub and create additional indentations.
>
> Many hubs have slightly cup shaped flanges that approximate the angle
> of the average spoke to the rim so that outbound spokes do not have so
> hard a time of aligning to the angle. These flanges are drilled, one
> hole at a time by an NC machine that indexes at the appropriate
> interval as the angled drill penetrates the flange normal to its
> surface.
On the other hand, many hubs I've examined have spoke holes formed
parallel to the hub axle, as Bill Platt explains. As I understand it
the holes in a single flange might be stamped out all at once, rather
than drilled as some hubs may be. That would explain the parallel axes
of the spoke holes in those hubs. Nevertheless it doesn't seem to make
any difference in practice -- the spoke line "corrects" easily and the
spokes seem happy enough in use.
Mark Hickey
>Just thinking about linseed oil smell gave me a warm fuzzy feeling when
>it was first mentioned.
I kinda like it too - not sure if it's because it's the "smell of
building wheels" or because it smells good (to me).
>So does it go just on the threads, or should some also go on the nipple
>shoulder?
I put it on the theads sparingly. What I'll do is bundle 15-20 spokes
together with the ends all aligned, and dip about 1/8" (3mm) of the
threads into the linseed oil. Then I'll roll the spokes around, which
distributes the oil uniformly over all the threads. It also saves a
lot of time and mess compared to trying to dip each one individually.
Ozark Bicycle
Mark Hickey wrote:
> joseph.sa...@gmail.com wrote:
>
> >Just thinking about linseed oil smell gave me a warm fuzzy feeling when
> >it was first mentioned.
>
> I kinda like it too - not sure if it's because it's the "smell of
> building wheels" or because it smells good (to me).
>
> >So does it go just on the threads, or should some also go on the nipple
> >shoulder?
>
> I put it on the theads sparingly. What I'll do is bundle 15-20 spokes
> together with the ends all aligned, and dip about 1/8" (3mm) of the
> threads into the linseed oil. Then I'll roll the spokes around, which
> distributes the oil uniformly over all the threads. It also saves a
> lot of time and mess compared to trying to dip each one individually.
>
>
One last thing, it takes a few days for the linseed oil to dry and act
as a thread lock. So after all the wheel building is completed, there
is an advantage to not using the wheels immediately. Yes, I know that
isn't always practical......
jim beam
can't directly link - it's on their "password protected" tech site.
fogel is the keyholder iirc.
jim beam
> jim beam wrote:>>>> http://www.flickr.com/photos/38636024@N00/104463818/
>>>>
>>>>>> the hub holes deform during the build. "correcting the spoke line"
>>>>>> before this process has occurred is premature and will leave the
>>>>>> spoke elbow with the wrong resultant angle. the spoke elbow comes
>>>>>> pre-formed with the best resultant angle and the hub flange is
>>>>>> canted and drilled also to give the best resultant angle. it may
>>>>>> look odd when first laced, but when fully tensioned, the net result
>>>>>> is optimized. i therefore say leave the spoke elbow angle alone -
>>>>>> do /not/ bend.
>>>>> too, but I've never loosened and examined a new wheel to see how
>>>>> much of that plastic forming takes place before it is even ridden.
>>>> It happens immediately when a spoke is tensioned as the flange
>>>> conforms to the shape of the spoke elbow which remains unchanged from
>>>> tensioning. Unspoking a tensioned wheel that has not been ridden
>>>> shows the spoke seating effect in its final condition. In use, spokes
>>>> do not increase in tension so there is no further deformation of
>>>> flange holes.
>>>>
>>>> The spoke line is best improved manually without the hazard of
>>>> damaging flanges by hammering. This is more apparent with large
>>>> flange hubs. Not improving the spoke line leaves spokes with higher
>>>> residual stress that is not easily removed otherwise. That is the
>>>> purpose of this step. That spokes do not lie flat against the flange
>>>> is apparent after tensioning and should be corrected.
>>>>
>>>> Jobst Brandt
>>> These are used hubs that show these flange deformations. The rear hub
>>> seems to only ever have been built up one way, while the front seems to
>>> have been used more than one way. I assume it would be best for me to
>>> assemble the rear wheel to match this deformation, but what about the
>>> front wheel? Does it really make any difference?
>> not really unless you plan on these hubs being ultra-high mileage,
>> loaded touring, etc.
>
> 120-160 miles per week with fully loaded weight of about 240 lbs. This
> is for my good-weather commuter. If the hubs break, I supose I'll just
> buy new ones, right?
if they ever do, yes! the theoretical "disadvantage" of reuse due to
hole deformation is extremely small and may indeed be mitigated by
re-orientation of the fatigue loads. i'd not worry about it personally
- if spoke tension is not excessive, the bearings are going to be toast
long before the flanges ever give out.
>
>>> These are low flange
>>> hubs and low profile rims, so the spoke angle is about as shallow as it
>>> is going to get on a front wheel.
>> use the "mavic" method of seating the spokes into the hub flanges - grip
>> the rim at opposite sides when laced and press the hub with your near
>> full body weight into a block of wood. this way, you can seat spokes
>> without having to bring them to tension first, hence avoiding this
>> bending business. the mavic pdf's on wheel building were on the mavic
>> tech web site last time i looked.
>
> I like that idea.
>
> Joseph
>
jim beam
> Bill Platt writes:
>
>>>> This is good news. The only problem I seem to have is that the
>>>> spokes and hubs I have don't seem to have the inbound and outbound
>>>> parts labeled. Is there some secret code?
>
>>> I've been watching this thread, hoping that I wasn't the only one
>>> with this question. How do you "cant and drill" a hole in the hub
>>> flange so that both inbound *and* outbound spokes are "optimized?"
>>> If the hole was so canted, would that mean that the hubs should not
>>> be deformed during the build?
>
>> I think with the exception of weird special purpose hubs, all the
>> holes are the same. There is no cant. The spoke is bent into a J
>> to take care of that. The holes are all drilled parallel to the hub
>> axis. The edges of the holes are chamfered, but as noted upthread,
>> the spokes seat into the hub and create additional indentations.
>
> Many hubs have slightly cup shaped flanges that approximate the angle
> of the average spoke to the rim so that outbound spokes do not have so
> hard a time of aligning to the angle. These flanges are drilled, one
> hole at a time by an NC machine that indexes at the appropriate
> interval as the angled drill penetrates the flange normal to its
> surface.
>
> When taking apart a wheel, the elbows of outbound spokes will have an
> acute angle and inbound ones an obtuse angle.
only if they've been bent by the wheel builder prior to hub hole
deformation. if the builder doesn't prematurely bend, and the "mavic
method" of bedding the spokes in is observed, there's no discernible
change in angle. not with 3x on quality hubs that have angled hub
flanges at any rate.
> The obtuse angle is the
> natural one from manufacture. The acute angle results from improving
> the spoke line, as was discussed here and explained in "the Bicycle
> Wheel".
i.e. premature bending.
> The angular difference is small but important. That is why
> changing a rim should be done without removing spokes from the hub
> while transferring them to the new rim, one at a time to prevent
> getting acute angled spokes into inbound positions.
elsewhere you write that spokes can be reused many times, regardless of
hub or rim. that necessarily means deployment changes. be truthful
jobst - the only real advantage to rim swapping in the way you describe
is ease of rebuild. it's not some form of fatigue-eliminating witchcraft.
> These cannot be
> improved in place.
that's true, but not for the reasons you're claiming.
me
"Ozark Bicycle" <bicycle...@ozarkbicycleservice.com> wrote in message
news:1163256914.6...@i42g2000cwa.googlegroups.com...
among the oil painting supplies. Add one or two drops to a small quantity
of linseed oil that you're going to use to lube your spoke threads. It
accelerates the polymerization of the linseed oil.
Cal
jim beam
> jim beam wrote:
>> http://www.flickr.com/photos/38636024@N00/104463818/
>>
>> the hub holes deform during the build. "correcting the spoke line"
>> before this process has occurred is premature and will leave the spoke
>> elbow with the wrong resultant angle. the spoke elbow comes pre-formed
>> with the best resultant angle and the hub flange is canted and drilled
>> also to give the best resultant angle. it may look odd when first
>> laced, but when fully tensioned, the net result is optimized. i
>> therefore say leave the spoke elbow angle alone - do /not/ bend.
>
> I wonder how long it takes to get that way. I've always noticed this
> too, but I've never loosened and examined a new wheel to see how much
>
if the spokes have been bedded in properly with over-stress, it's all
done before the wheel's ever ridden.
joseph.sa...@gmail.com
Ozark Bicycle wrote:
> joseph.sa...@gmail.com wrote:
> > Ozark Bicycle wrote:
> > > Sheldon Brown wrote:
> > > > Ben C wrote:
> > > >
> > > > > > So does linseed oil actually lock the threads?
> > > > > > I thought it was just to
> > > > > > lubricate them a bit and provide a corrosion barrier.
> > > >
> > > > Ozark Bicycle replied:
> > > >
> > > > > When wet, it lubes the spoke threads. When it dries, it provides a
> > > > > gentle thread lock.
> > > >
> > > > Yep, this is a traditional technique, works very well...if you can
> > > > stand the smel!
> > > >
> > >
> > > When I began to use linseed oil in wheelbuilding ~20 years ago, I was
> > > already appreciative of the smell from my woodworking stuff. YNMV.
> > >
> > > And it does work well, at least as well as "Spoke Prep" and much more
> > > realistically priced.
> > >
> >
> > Just thinking about linseed oil smell gave me a warm fuzzy feeling when
> > it was first mentioned.
> >
>
> Is this from woodworking/refinishing experience?
Furniture making and resoration on a crude amateur level! I haven't
done it in years, but the smells and the smooth-finger sawdust and
sand-paper feel sure is comforting.
>
> > So does it go just on the threads, or should some also go on the nipple
> > shoulder?
> >
>
> I just put it on the threads.
>
> And your workspace will be filled with the smell of linseed oil! :-)
Sitting in my decrepit shed with a dim light hanging from the end of an
extension cord, smelling linseed oil while fiddling with my wheels as
winter winds howl outside is about are close to nirvana as I can
imagine!
Joseph
Peter Cole
Found the site, read the pdf's -- couldn't find anything like you describe.
login "mavic-com" password "dealer"
Ozark Bicycle
Thanks for the tip! I'll try that.
jim beam
the mavic pdf i have saved to my system is titled SpokeTension.pdf
text is:
TENSION OF THE SPOKES
Perform each of the following procedures always starting from the valve
hole.
1 Place the wheel in the truing stand and put a drop of spoke prep on
each visible threaded zone of the spoke heads.
2 Tighten each nipple in a progressive and uniform manner. (For example,
tighten each nipple 1 turn, one after the other). For optimum mounting,
you need to stress relieve the spokes so the elbows closely follow the
shape of the hub flange. Repeat this procedure until you obtain tension
in the spokes.
3 Place the wheel in the truing stand and check that the wheel is
globally centered (use the dishing tool if necessary). If this is the
case, continue to tighten the spokes in a uniform manner. If this is not
the case, tighten the spokes as consistently as possible on the left
side, if the wheel is too far to the right, or vice-versa.
4 The wheel should rotate almost totally round (no vertical or lateral
movements). However, if the wheel has vertical movement, tighten a spoke
on each side in the problem area (bump). You must systematically work
both sides so that the lateral movement is not affected. If the wheel
has lateral movement, tighten two spokes on the same side in the problem
area (bump). You must work at least two spokes on the same side so that
the vertical movement is not affected.
5 Check the tension of the spokes with a tensionometer (see photo). At
this stage, we recommend an approximate tension of:
- 40 - 60 daN on the front wheel.
- 40 - 60 daN on the free wheel side of the rear wheel.
An exact relationship between the two sides of the rear wheel is
relatively difficult. The tension of the spokes on the free wheel side
is approximately 70 % higher than the tension of the spokes on the
opposite side.
6 When there is no lateral or vertical movement, put the hub axle of the
wheel on a wooden block and push on opposite sides of the rim with your
hands. The spokes and nipples will now "seat" in position (stress
relieving).
7 Increase the tension of the spokes while checking the vertical and
lateral movements of the wheel to reach a final tension of approximately:
- 90 - 110 daN on the front wheel.
- 90 - 110 daN on the free wheel side of the rear wheel.
8 Repeat procedures 6 and 7 until the wheel is perfect and the spokes
make no more cracking sounds.
carl...@comcast.net
Dear Peter,
I just looked and found that Mavic re-did their wretched website in
mid-October. You still can't search it, but it looks as if there's less
to rummage through. Mavic may have tossed out some stuff when they
re-did their web-site.
Like you, I couldn't find the pdf, either, but what Jim Beam wrote
sounded familiar, and I see that he's posted a saved copy. I can't
remember well enough to say if I'm confusing Mavic with the Bontrager
stressor box that Dianne pointed out:
http://www.bontrager.com/assets/File_Listings/asset_upload_file325_970.pdf
The long Bontrager pdf has stuff about correcting the spoke line and
then about the spoke stressor box, which could be described as a stand
for squashing all the spokes at once at the hub with a screw-jack--look
at the pictures and it's a fairly simple tool.
Cheers,
Carl Fogel
carl...@comcast.net
Dear Peter,
Here's the old Mavic pdf from Jim Beam:
http://home.comcast.net/~carlfogel/download/SpokeTension.pdf
"Step 6 When there is no lateral or vertical movement, put the hub axle
of the wheel on a wooden block and push on opposite sides of the rim
with your hands. The spokes and nipples will now 'seat' in position
(stress relieving)."
The Mavic page indicated that this is first done at about 40-60 kgf
spoke tension on a wheel that will end up at 90-110 kgf, and then
repeated as the tension is increased "until the wheel is perfect and
the spokes make no more cracking sounds."
Maybe it's still somewhere on the Mavic site, but I can't find it.
Cheers,
Carl Fogel
Ben C
[snip]
> I just looked and found that Mavic re-did their wretched website in
> mid-October. You still can't search it, but it looks as if there's less
> to rummage through. Mavic may have tossed out some stuff when they
> re-did their web-site.
>
> Like you, I couldn't find the pdf, either, but what Jim Beam wrote
> sounded familiar, and I see that he's posted a saved copy.
Their website is certainly wretched, but the pdf is there, it's called
"SpokeTension.pdf", and I think it's under the "Rims" heading rather
than the "Wheels" heading.
Tim McNamara
carl...@comcast.net wrote:
> Here's the old Mavic pdf from Jim Beam:
>
> http://home.comcast.net/~carlfogel/download/SpokeTension.pdf
>
> "Step 6 When there is no lateral or vertical movement, put the hub
> axle of the wheel on a wooden block and push on opposite sides of the
> rim with your hands. The spokes and nipples will now 'seat' in
> position (stress relieving)."
Which is not stress relieving, of course. It is releasing the spoke
windup from improper spoke tightening technique.
> The Mavic page indicated that this is first done at about 40-60 kgf
> spoke tension on a wheel that will end up at 90-110 kgf, and then
> repeated as the tension is increased "until the wheel is perfect and
> the spokes make no more cracking sounds."
Yikes.
jobst....@stanfordalumni.org
>> I just looked and found that Mavic re-did their wretched website in
>> mid-October. You still can't search it, but it looks as if there's
>> less to rummage through. Mavic may have tossed out some stuff when
>> they re-did their web-site.
>> Like you, I couldn't find the pdf, either, but what Jim Beam wrote
>> sounded familiar, and I see that he's posted a saved copy.
> Their website is certainly wretched, but the pdf is there, it's
> called "SpokeTension.pdf", and I think it's under the "Rims" heading
> rather than the "Wheels" heading.
I don't think they know any more about wheels than web site design.
Their products have had failures ever since the original Mavic name
was absorbed in the Solomon Group. This pushing-on-the-rim bit only
relaxes underside spokes and does nothing for seating, which occurs
naturally with tensioning the wheel. Their method is a crude way of
untwisting spokes, much like cracking knuckles, once a popular gesture
in preparation for physical exertion. It gave a reassuring sound.
Jobst Brandt
carl...@comcast.net
Dear Ben,
You're right--the wood block pdf is still on the Mavic site.
Peter and I didn't find it because the site is such a hideously
unorganized mess.
Go here and login as "mavic.com" using password "dealer":
http://www.tech-mavic.com/tech-mavic/technical_manual/data/
Hit enter and wait while something useless slowly loads.
Click on "Prior 2007 Documentation" and wait for a new window to open.
Click on "Road and Triathlon."
Click on "Rims" instead of "Wheels" because the wheels are already
built, so wheel-building is covered under rims--très logique!
Look at the "Wheel Building" pdf--no, that's not it.
Try the "Wheel Building continued" pdf--that's not it, either.
Hmmm . . . try the "Spoke Tension" pdf--there it is, the wood block
and push on opposite sides of the rim stress-relief technique!
http://www.tech-mavic.com/tech-mavic/technical_manual/data/tech-mavic/uk/sources/Produits/ROUTE/Jantes/GalJtesRte/SpokeTension.pdf
or http://tinyurl.com/yfq5cl
Apparently, this technique is now considered pre-2007, since it
doesn't appear in the mammoth "Complete 2007 technical manual" pdf or
in the "rims" or "wheels" section at the opening of the newly
mis-designed site.
One theory is that Mavic requires a login and password to keep the
public out of its web site, lest we become frustrated.
Cheers,
Carl Fogel
jim beam
> In article <1163315688.0...@e3g2000cwe.googlegroups.com>,
> carl...@comcast.net wrote:
>
>> Here's the old Mavic pdf from Jim Beam:
>>
>> http://home.comcast.net/~carlfogel/download/SpokeTension.pdf
>>
>> "Step 6 When there is no lateral or vertical movement, put the hub
>> axle of the wheel on a wooden block and push on opposite sides of the
>> rim with your hands. The spokes and nipples will now 'seat' in
>> position (stress relieving)."
>
> Which is not stress relieving, of course. It is releasing the spoke
> windup from improper spoke tightening technique.
but tim, it /does/ raise spoke tension on the side closest the operator
[you can check that yourself with a tensiometer or spoke plucking if you
have an assistant], so it achieves exactly the same function as spoke
squeezing. the advantage of this method is that you don't need to have
the spokes tensioned to be able to start bedding the spokes into the hub
holes, unlike spoke squeezing. it's also easier to apply body weight to
a rim rather than grip wire by hand.
>
>> The Mavic page indicated that this is first done at about 40-60 kgf
>> spoke tension on a wheel that will end up at 90-110 kgf, and then
>> repeated as the tension is increased "until the wheel is perfect and
>> the spokes make no more cracking sounds."
>
> Yikes.
why? you get the same noises with other "stress relief" methods.
jim beam
> Ben C? writes:
>
>>> I just looked and found that Mavic re-did their wretched website in
>>> mid-October. You still can't search it, but it looks as if there's
>>> less to rummage through. Mavic may have tossed out some stuff when
>>> they re-did their web-site.
>
>>> Like you, I couldn't find the pdf, either, but what Jim Beam wrote
>>> sounded familiar, and I see that he's posted a saved copy.
>
>> Their website is certainly wretched, but the pdf is there, it's
>> called "SpokeTension.pdf", and I think it's under the "Rims" heading
>> rather than the "Wheels" heading.
>
> I don't think they know any more about wheels than web site design.
> Their products have had failures ever since the original Mavic name
> was absorbed in the Solomon Group. This pushing-on-the-rim bit only
> relaxes underside spokes and does nothing for seating,
presumptive nonsense proving that you've never done it. honestly jobst,
the shit you write sometimes is simply shameful.
> which occurs
> naturally with tensioning the wheel.
more fundamentally untrue drivel. unlike you, /i/ have tested this
presumptive nonsense, and have proven it untrue. not that i really
needed to bother since anyone that has actually done a brinell test
would know that the higher the load, the deeper the indent - spokes in
hub flanges are exactly the same principle.
> Their method is a crude way of
> untwisting spokes,
it's no worse than gripping spokes by hand, and works for /all/ spoking
patterns.
> much like cracking knuckles, once a popular gesture
> in preparation for physical exertion. It gave a reassuring sound.
irrelevant drivel.
on the one hand jobst, your ability to present nonsense as fact is
disgusting. on the other, it's perversely impressive that you can do so
without any evidence of shame.
carl...@comcast.net
>This pushing-on-the-rim bit only
>relaxes underside spokes . . .
Dear Jobst,
What do you predict will be shown by a spoke tension gauge when I try
this technique of leaning on a horizontal wheel with one hand on
either side of the rim?
That is, what will the top and bottom spokes do around the clock, with
my hands at 9 and 3 o'clock? Which will gain tension, which will lose
tension, and how much?
I haven't tried it yet, so this would be a good chance to test whether
theory predicts results.
Cheers,
Carl Fogel
Joe Riel
Assuming a radially spoked front wheel, I'd expect that, for a small
displacement, the decrease in tension of the lower spokes is matched
by an increase in tension of the upper spokes. The largest changes
would be at the 3 and 9 o'oclock, the smallest at 6 and 12. Things
may be a bit more complicated for a 3x wheel.
--
Joe Riel
bill
jobst....@stanfordalumni.org wrote:
"Many hubs have slightly cup shaped flanges that approximate the angle
of the average spoke to the rim so that outbound spokes do not have so
hard a time of aligning to the angle. These flanges are drilled, one
hole at a time by an NC machine that indexes at the appropriate
interval as the angled drill penetrates the flange normal to its
surface. "
Very cool. I didn't know that! I wonder how far back that goes?
jobst....@stanfordalumni.org
>> This pushing-on-the-rim bit only relaxes underside spokes . . .
> What do you predict will be shown by a spoke tension gauge when I
> try this technique of leaning on a horizontal wheel with one hand on
> either side of the rim?
I was wrong about the method. It increases spoke tension by about 20%
on a tight spoke. The bottom spoke at that location goes anywhere
from losing 3/4 of its tension to slack, depending on whether it is a
dished or symmetrical wheel. This was a rear wheel with sprockets up.
On a low tension wheel the upper spoke gains a larger but undefined
amount of tension relative to its starting point because that may be
practically slack. Of course the under side spoke goes slack with
even slight pressure, not having much to start with.
> That is, what will the top and bottom spokes do around the clock,
> with my hands at 9 and 3 o'clock? Which will gain tension, which
> will lose tension, and how much?
> I haven't tried it yet, so this would be a good chance to test
> whether theory predicts results.
I guess you will find similar results, however, depending on how tight
the wheel is, will affect the change in the upper spoke at place being
pushed. In any event, it has more than double the effect of squeezing
pairs of spokes. The amount is difficult to assess because the
tensiometer occupies the place on the spoke where one would grasp a
spoke pair.
Jobst Brandt
Ben C
> On Sun, 12 Nov 2006 03:55:51 -0600, Ben C <spam...@spam.eggs> wrote:
>
>>On 2006-11-12, carl...@comcast.net <carl...@comcast.net> wrote:
>>[snip]
>>> I just looked and found that Mavic re-did their wretched website in
>>> mid-October. You still can't search it, but it looks as if there's less
>>> to rummage through. Mavic may have tossed out some stuff when they
>>> re-did their web-site.
>>>
>>> Like you, I couldn't find the pdf, either, but what Jim Beam wrote
>>> sounded familiar, and I see that he's posted a saved copy.
>>
>>Their website is certainly wretched, but the pdf is there, it's called
>>"SpokeTension.pdf", and I think it's under the "Rims" heading rather
>>than the "Wheels" heading.
>
> Dear Ben,
>
> You're right--the wood block pdf is still on the Mavic site.
>
> Peter and I didn't find it because the site is such a hideously
> unorganized mess.
> Apparently, this technique is now considered pre-2007, since it
> doesn't appear in the mammoth "Complete 2007 technical manual" pdf or
> in the "rims" or "wheels" section at the opening of the newly
> mis-designed site.
The 2007 WheelBuilding.pdf and WheelBuildingContinued.pdf seem to be
explanations of how to assemble "boutique" wheels with very few spokes
and/or radial lacings on the front wheel. They did say somewhere that
the 2007 manuals covered things that hadn't been covered in previous
manuals.
Interestingly the spoke tension required for these wheels with very few
spokes doesn't seem to be all that high.
> One theory is that Mavic requires a login and password to keep the
> public out of its web site, lest we become frustrated.
One thing that is quite useful is that you can get the dimensions of
individual rims for checking spoke lengths without relying on the rims
being in the database of the spoke length calculator you're using.
And the wood block technique doesn't sound like a bad idea to me. I
tried it on a wheel I've been practising on, and it brought out lots of
cracking sounds that I hadn't uncovered by squeezing spoke pairs,
implying that it was doing a good job of relieving or seating something.
Ben C
>
> Ben C wrote:
[snip]
>> So does linseed oil actually lock the threads?
>
> gentle thread lock.
Thanks everyone, I did actually find some of the stuff, so I'll give it
a go.
carl...@comcast.net
Dear Ben,
I haven't tried the wood block technique yet. I've drilled some holes
in a metal bar to make a rig, but I need to pick up some lag bolts to
anchor things.
Jobst and Joe Riel have offered some further comments.
I did take the front wheel off the Fury RoadMaster, which had about a
thousand miles on it and whose spokes had been squeezed in a hopeful
fashion.
When I leaned on the horizontal rim, I got the same cracking noises
that you noticed, which makes me wonder if tension might be raised
higher or reduced lower than by squeezing spokes pairs. I couldn't
tell which spokes were making the cracking noises, which soon stopped,
consistent with a spoke and nipple unwinding.
I'm about 190~195 lbs. When I leaned on a bathroom scale on a counter,
it showed about 100 lbs. I'm really curious to see what happens to
spoke tension when I load the sides of the horizontal rim.
Cheers,
Carl Fogel
dvt
> Bill Platt writes:
>>> How do you "cant and drill" a hole in the hub
>>> flange so that both inbound *and* outbound spokes are "optimized?"
>>> If the hole was so canted, would that mean that the hubs should not
>>> be deformed during the build?
>
>> I think with the exception of weird special purpose hubs, all the
>> holes are the same. There is no cant. The spoke is bent into a J
>> to take care of that. The holes are all drilled parallel to the hub
>> axis. The edges of the holes are chamfered, but as noted upthread,
>> the spokes seat into the hub and create additional indentations.
>
> of the average spoke to the rim so that outbound spokes do not have so
> hard a time of aligning to the angle. These flanges are drilled, one
> hole at a time by an NC machine that indexes at the appropriate
> interval as the angled drill penetrates the flange normal to its
> surface.
No matter which method was used to make the holes, I haven't figured out
how to cant the holes of the hub "optimally" for all of the variations
of outbound/inbound and crossing patterns. I hope jim beam can clarify.
--
Dave
dvt at psu dot edu
Everyone confesses that exertion which brings out all the powers of body
and mind is the best thing for us; but most people do all they can to
get rid of it, and as a general rule nobody does much more than
circumstances drive them to do. -Harriet Beecher Stowe, abolitionist and
novelist (1811-1896)
AndyMorris
> Ben C wrote:
>
>>> lubricate them a bit and provide a corrosion barrier.
>
> Ozark Bicycle replied:
>
>> gentle thread lock.
>
> stand the smel!
>
>
> Sheldon "Yeccccch" Brown
Presumably, teflon lube, is not such a good idea.
Its all I had at the time.
--
Andy Morris
AndyAtJinkasDotFreeserve.Co.UK
Love this:
Put an end to Outlook Express's messy quotes
http://home.in.tum.de/~jain/software/oe-quotefix/
--
Posted via NewsDemon.com - Premium Uncensored Newsgroup Service
------->>>>>>http://www.NewsDemon.com<<<<<<------
Unlimited Access, Anonymous Accounts, Uncensored Broadband Access
jobst....@stanfordalumni.org
>>>> So does linseed oil actually lock the threads? I thought it was
>>>> just to lubricate them a bit and provide a corrosion barrier.
>>> When wet, it lubes the spoke threads. When it dries, it provides
>>> a gentle thread lock.
Linseed oil doesn't "dry" by evaporation but rather polymerizes and
becomes a stiff tar. Vegetable oils of various kinds (olive oil) do
that in the kitchen while oxidizing and becoming rancid.
>> Yep, this is a traditional technique, works very well...if you can
>> stand the smell!
>> Personally, I can't.
> Presumably, Teflon lube, is not such a good idea.
> Its all I had at the time.
Why would Teflon lube be a bad idea. Maybe you don't understand what
all this thread locking stuff is about. Unless spokes repeatedly
become slack in use, spoke nipples cannot unscrew. This whole concept
arose wit machine built wheels that could not be made adequately
tight. Therefore, since low tension spokes become slack frequently
when in use, especially with a heavy rider or on rough roads, such
wheels came out of true.
Wheelsmith had one of the first Holland Mechanics wheel building
stations in the USA and developed SpokePrep to cover for loosely
spoked wheels that they produced. With the fad of wheels with few
spokes in full swing, even more wheels that formerly are at risk of
loosening spokes in normal use.
Ten spokes! Quick, where's the Loctite!
Jobst Brandt
jobst....@stanfordalumni.org
>>>> So does linseed oil actually lock the threads? I thought it was
>>>> just to lubricate them a bit and provide a corrosion barrier.
>>> When wet, it lubes the spoke threads. When it dries, it provides
>>> a gentle thread lock.
Linseed oil doesn't "dry" by evaporation but rather by polymerizing
and becoming a stiff tar. Vegetable oils of various kinds (olive oil)
do that in the kitchen while oxidizing and becoming rancid.
>> Yep, this is a traditional technique, works very well...if you can
>> stand the smell!
>> Personally, I can't.
> Presumably, Teflon lube, is not such a good idea.
> Its all I had at the time.
Why would Teflon lube be a bad idea. Maybe you don't understand what
all this thread locking stuff is about. Unless spokes repeatedly
become slack in use, spoke nipples cannot unscrew. This whole concept
arose with machine built wheels that could not be made adequately
tight. That of course is a subject all for itself (a thread that can
be found on the web). Therefore, since wheels with low tension spokes
that become slack frequently in use, especially with a heavy rider or
on rough roads, they became untrue.
Wheelsmith had one of the first Holland Mechanics wheel building
stations in the USA and developed SpokePrep to cover for loosely
spoked wheels they produced. With the fad of wheels with few spokes
in full swing, even more wheels than formerly are subject to loosening
Ozark Bicycle
jobst.bra...@stanfordalumni.org wrote:
> Andy Morris writes:
>
> >>>> So does linseed oil actually lock the threads? I thought it was
> >>>> just to lubricate them a bit and provide a corrosion barrier.
>
> >>> When wet, it lubes the spoke threads. When it dries, it provides
> >>> a gentle thread lock.
>
> Linseed oil doesn't "dry" by evaporation but rather polymerizes and
> becomes a stiff tar.
Geez, who cares? The end result is the same: a gentle threadlock
> Vegetable oils of various kinds (olive oil) do
> that in the kitchen while oxidizing and becoming rancid.
I'll keep that in mind the next time I have the urge to use linseed oil
in my balsamic vinegrette!
Or olive oil on my spoke threads.....
>
> >> Yep, this is a traditional technique, works very well...if you can
> >> stand the smell!
>
> >> Personally, I can't.
>
> > Presumably, Teflon lube, is not such a good idea.
>
> > Its all I had at the time.
>
> Why would Teflon lube be a bad idea. Maybe you don't understand what
> all this thread locking stuff is about. Unless spokes repeatedly
> become slack in use, spoke nipples cannot unscrew. This whole concept
> arose wit machine built wheels that could not be made adequately
> tight.
Actually, Jobst, I believe the use of linseed oil as a threadlock on
handbuilt wheels predates all this. I would love to see solid evidence
to the contrary. Or even solid evidence of the widespread use of
linseed oil on machine built wheels. Can you provide such solid
evidence for either case?
Ben C
[snip]
> Why would Teflon lube be a bad idea. Maybe you don't understand what
> all this thread locking stuff is about. Unless spokes repeatedly
> become slack in use, spoke nipples cannot unscrew. This whole concept
> arose with machine built wheels that could not be made adequately
> tight. That of course is a subject all for itself (a thread that can
> be found on the web). Therefore, since wheels with low tension spokes
> that become slack frequently in use, especially with a heavy rider or
> on rough roads, they became untrue.
>
> Wheelsmith had one of the first Holland Mechanics wheel building
> stations in the USA and developed SpokePrep to cover for loosely
> spoked wheels they produced. With the fad of wheels with few spokes
> in full swing, even more wheels than formerly are subject to loosening
> spokes in normal use.
Is this because wheels with few spokes are built with a lower spoke
tension (for some reason) or is it because the rim is supported at fewer
points, and therefore the spokes share the load less, meaning each
individual spoke is dentensioned more as it passes through the contact
patch?
Sheldon's site, and common sense, say the tension should be as high as
you can get it without things cracking or threads stripping etc. at
wheel-building time.
But rim manufacturers don't recommend such high tensions from what I can
see. I tried searching the r.b.t. archives and found some discussion of
the possibility of increased corrosion leading to cracking around the
eyelets if the tension is high.
A common failure of rims is cracking around the eyelets. I had this on
my own rear rim. On the one hand insufficient tension could explain
this, because if the bottom spoke goes completely slack, the top spoke
will actually be pulled out through the eyelet. Another explanation is
that slacker spokes will deflect more as they detension, meaning more
movement and therefore wear around the eyelet. On the other hand, if the
rate of wear is not affected by tension, you might expect the actual
failure to occur sooner with a higher tension, as the point at which the
rim can no longer support the spoke tension will come sooner.
Do people usually see cracked eyelets on the drive side or on the
non-drive side of rear wheels? Maybe this would be an indicator of
whether high tension or low tension wears the rim more at the eyelets.
jobst....@stanfordalumni.org
>> Why would Teflon lube be a bad idea. Maybe you don't understand
>> what all this thread locking stuff is about. Unless spokes
>> repeatedly become slack in use, spoke nipples cannot unscrew. This
>> whole concept arose with machine built wheels that could not be
>> made adequately tight. That of course is a subject all for itself
>> (a thread that can be found on the web). Therefore, since wheels
>> with low tension spokes that become slack frequently in use,
>> especially with a heavy rider or on rough roads, they became
>> untrue.
>> Wheelsmith had one of the first Holland Mechanics wheel building
>> stations in the USA and developed SpokePrep to cover for loosely
>> spoked wheels they produced. With the fad of wheels with few
>> spokes in full swing, even more wheels than formerly are subject to
>> loosening spokes in normal use.
> Is this because wheels with few spokes are built with a lower spoke
> tension (for some reason) or is it because the rim is supported at
> fewer points, and therefore the spokes share the load less, meaning
> each individual spoke is dentensioned more as it passes through the
> contact patch?
Spoke tension with fewer spokes must be higher than for a 36 spokes,
for instance, because only one or two spokes are supporting the load.
Check out the thread of "the wheel stands on the bottom spokes".
> Sheldon's site, and common sense, say the tension should be as high
> as you can get it without things cracking or threads stripping
> etc. at wheel-building time.
> But rim manufacturers don't recommend such high tensions from what I
> can see. I tried searching the r.b.t. archives and found some
> discussion of the possibility of increased corrosion leading to
> cracking around the eyelets if the tension is high.
> A common failure of rims is cracking around the eyelets. I had this
> on my own rear rim. On the one hand insufficient tension could
> explain this, because if the bottom spoke goes completely slack, the
> top spoke will actually be pulled out through the eyelet.
That occurs because rims are no longer built with sockets that
distribute spoke loads to inner and outer beds of the rim. Spoke
loads are concentrated on an eyelet whose diameter is little more than
a spoke nipple while sockets are more than 10mm in diameter at the
mouth and bear on both rim beds.
> Another explanation is that slacker spokes will deflect more as they
> detension, meaning more movement and therefore wear around the
> eyelet. On the other hand, if the rate of wear is not affected by
> tension, you might expect the actual failure to occur sooner with a
> higher tension, as the point at which the rim can no longer support
> the spoke tension will come sooner.
Spokes either bear the load by losing tension, or go slack and allow
spoke nipples to unscrew for which glue has become popular.
> Do people usually see cracked eyelets on the drive side or on the
> non-drive side of rear wheels? Maybe this would be an indicator of
> whether high tension or low tension wears the rim more at the
> eyelets.
They see them on both sides and front wheels. The deep cross section
aero rims avoid that because the load hangs in the bottom of the "V"
on a relatively thick aluminum bed.
Jobst Brandt
Ben C
[snip]
>> A common failure of rims is cracking around the eyelets. I had this
>> on my own rear rim. On the one hand insufficient tension could
>> explain this, because if the bottom spoke goes completely slack, the
>> top spoke will actually be pulled out through the eyelet.
>
> That occurs because rims are no longer built with sockets that
> distribute spoke loads to inner and outer beds of the rim. Spoke
> loads are concentrated on an eyelet whose diameter is little more than
> a spoke nipple while sockets are more than 10mm in diameter at the
> mouth and bear on both rim beds.
Now you mention it I think I dimly remember those sockets from some
Mavic rims I had about 15 years ago.
>> Another explanation is that slacker spokes will deflect more as they
>> detension, meaning more movement and therefore wear around the
>> eyelet. On the other hand, if the rate of wear is not affected by
>> tension, you might expect the actual failure to occur sooner with a
>> higher tension, as the point at which the rim can no longer support
>> the spoke tension will come sooner.
>
> Spokes either bear the load by losing tension, or go slack and allow
> spoke nipples to unscrew for which glue has become popular.
I just meant the pre-tension. A spoke might be pulling on the eyelet
with a force of 900N (the wheel is in the truing stand for the sake of
argument, or floating around in an orbiting spacecraft, it doesn't
matter). The rim can withstand 900N and so doesn't crack. But over time
as the rim wears, it reaches a point where it can only withstand 890N,
so it cracks. But if the spoke had only been at 850N tension all along,
perhaps the rim would last a bit longer, assuming the rate of wear at
850N and 900N were about the same, which may be a false assumption. This
might be a reason for building wheels tight enough but not too tight.
jim beam
> Ben C? writes:
>
>>> Why would Teflon lube be a bad idea. Maybe you don't understand
>>> what all this thread locking stuff is about. Unless spokes
>>> repeatedly become slack in use, spoke nipples cannot unscrew. This
>>> whole concept arose with machine built wheels that could not be
>>> made adequately tight. That of course is a subject all for itself
>>> (a thread that can be found on the web). Therefore, since wheels
>>> with low tension spokes that become slack frequently in use,
>>> especially with a heavy rider or on rough roads, they became
>>> untrue.
>
>>> Wheelsmith had one of the first Holland Mechanics wheel building
>>> stations in the USA and developed SpokePrep to cover for loosely
>>> spoked wheels they produced. With the fad of wheels with few
>>> spokes in full swing, even more wheels than formerly are subject to
>>> loosening spokes in normal use.
>
>> Is this because wheels with few spokes are built with a lower spoke
>> tension (for some reason) or is it because the rim is supported at
>> fewer points, and therefore the spokes share the load less, meaning
>> each individual spoke is dentensioned more as it passes through the
>> contact patch?
>
> Spoke tension with fewer spokes must be higher than for a 36 spokes,
rubbish. check with mavic, velocity, alex, any of the rim manufacturers
- tension specs are the same regardless of drilling count. spoke
tension is determined by the fatigue properties of the rim. once spoke
tension is sufficient to not let spokes go slack, increasing spoke
tension above that level does NOT increase the strength of the wheel.
all it does is "borrow" bending "strength" from the rim to give
compressive "strength" to the spokes - a pointless exercise for
structural purposes, and one that raises loading in the rim closer to
both of its taco and cracking limits.
> for instance, because only one or two spokes are supporting the load.
> Check out the thread of "the wheel stands on the bottom spokes".
red herring.
>
>> Sheldon's site, and common sense, say the tension should be as high
>> as you can get it without things cracking or threads stripping
>> etc. at wheel-building time.
>
>> But rim manufacturers don't recommend such high tensions from what I
>> can see. I tried searching the r.b.t. archives and found some
>> discussion of the possibility of increased corrosion leading to
>> cracking around the eyelets if the tension is high.
>
>> A common failure of rims is cracking around the eyelets. I had this
>> on my own rear rim. On the one hand insufficient tension could
>> explain this, because if the bottom spoke goes completely slack, the
>> top spoke will actually be pulled out through the eyelet.
>
> That occurs because rims are no longer built with sockets that
> distribute spoke loads to inner and outer beds of the rim.
untrue.
> Spoke
> loads are concentrated on an eyelet whose diameter is little more than
> a spoke nipple while sockets are more than 10mm in diameter at the
> mouth and bear on both rim beds.
distorted rubbish. do the math.
>
>> Another explanation is that slacker spokes will deflect more as they
>> detension, meaning more movement and therefore wear around the
>> eyelet. On the other hand, if the rate of wear is not affected by
>> tension, you might expect the actual failure to occur sooner with a
>> higher tension, as the point at which the rim can no longer support
>> the spoke tension will come sooner.
>
> Spokes either bear the load by losing tension,
so what happens to rims? according to jobstian theory, this wheel
should collapse:
http://home.comcast.net/~carlfogel/download/205lbs.jpeg
but it doesn't. why? because the rim is part of the load support
equation, something you /always/ ignore!
> or go slack and allow
> spoke nipples to unscrew for which glue has become popular.
so what? it works, and works well. and more moderate tension prevents
rims from cracking.
>
>> Do people usually see cracked eyelets on the drive side or on the
>> non-drive side of rear wheels? Maybe this would be an indicator of
>> whether high tension or low tension wears the rim more at the
>> eyelets.
>
> They see them on both sides and front wheels.
on rims with excessive tension, yes. on rims with more moderated
tension, the only time they're seen, [if at all] is on the drive side
rear - where tension increases due to the low bracing angle are
significant. you know that tension increase is a function of 1/sin
theta, right?
> The deep cross section
> aero rims avoid that because the load hangs in the bottom of the "V"
> on a relatively thick aluminum bed.
the only benefit of the deep section is rim stiffness - the stiffer the
rim, the less the load cycle magnitude on rim /and/ spoke. other than
that, a thick bed on /any/ rim helps mitigate cracking.
jim beam
can't say that. the rim doesn't wear in the section that has the point
contact load, so you're not going to see yield decrease over time.
fatigue properties depend on how far along the s-n graph you are.
> But if the spoke had only been at 850N tension all along,
> perhaps the rim would last a bit longer,
perhaps, but...
> assuming the rate of wear at
> 850N and 900N were about the same,
not as a function of wear!
> which may be a false assumption.
indeed, if you base it on wear. fatigue life is another matter, and may
indeed be mitigated by lower tension.
> This
> might be a reason for building wheels tight enough but not too tight.
build to rim manufacturer spec. no less, no more. if, as can sometimes
be the case with todays highly dished wheels, non-drive side spoke
nipples get slack enough to unscrew, use thread lock. that's why it's sold.
Ben C
On 2006-11-18, jim beam <spamv...@bad.example.net> wrote:
> jobst....@stanfordalumni.org wrote:
>> Ben C? writes:
>>
[snip]
>>
>>>> Wheelsmith had one of the first Holland Mechanics wheel building
>>>> stations in the USA and developed SpokePrep to cover for loosely
>>>> spoked wheels they produced. With the fad of wheels with few
>>>> spokes in full swing, even more wheels than formerly are subject to
>>>> loosening spokes in normal use.
>>
>>> Is this because wheels with few spokes are built with a lower spoke
>>> tension (for some reason) or is it because the rim is supported at
>>> fewer points, and therefore the spokes share the load less, meaning
>>> each individual spoke is dentensioned more as it passes through the
>>> contact patch?
>>
>> Spoke tension with fewer spokes must be higher than for a 36 spokes,
>
> rubbish. check with mavic, velocity, alex, any of the rim manufacturers
> - tension specs are the same regardless of drilling count. spoke
> tension is determined by the fatigue properties of the rim. once spoke
> tension is sufficient to not let spokes go slack, increasing spoke
> tension above that level does NOT increase the strength of the wheel.
> all it does is "borrow" bending "strength" from the rim to give
> compressive "strength" to the spokes - a pointless exercise for
> structural purposes, and one that raises loading in the rim closer to
> both of its taco and cracking limits.
Mavic say this:
"
Screw the nut of the socket and increase the tension of the spokes after
putting one or two drops of Mavic thread lock on the socket thread
(Crossmax UST and Ksyrium SSC only) :
- 70 - 90 kg for a front Crossride or Cosmos wheel.
- 110 - 130 kg for a front Cosmic Carbone SSC wheel.
- Ksyrium SSC : 90 - 110 kg for the front wheel and 130 - 150 kg for the
rear wheel on the free wheel side.
- Crossmax UST : 100 - 120 kg for the front wheel and 130 - 150 kg for
the rear wheel on the free wheel side.
"
Most or all of these wheels have less than 32 spokes.
[snip]
>> or go slack and allow
>> spoke nipples to unscrew for which glue has become popular.
>
> so what? it works, and works well. and more moderate tension prevents
> rims from cracking.
Are there any other harmful sideeffects of spokes going completely slack
besides just the nipples unscrewing?
For example, these are the things I'm concerned about:
1. increased fatigue around the nipple because of higher deflection.
2. the top spokes increasing in tension beyond the original pretension
because the load exceeds the pretension of the bottom spokes (they go
completely slack).
3. increased fatigue of the spokes themselves, perhaps around the elbow,
because they are actually being bent slightly in compression, leading
them to break.
>>> Do people usually see cracked eyelets on the drive side or on the
>>> non-drive side of rear wheels? Maybe this would be an indicator of
>>> whether high tension or low tension wears the rim more at the
>>> eyelets.
>>
>> They see them on both sides and front wheels.
>
> on rims with excessive tension, yes. on rims with more moderated
> tension, the only time they're seen, [if at all] is on the drive side
> rear - where tension increases due to the low bracing angle are
> significant. you know that tension increase is a function of 1/sin
> theta, right?
So are you saying excessive tension does actually promote cracking
around the eyelets in use (as opposed to the cracks appearing in the
truing stand before the wheel's even been put on the bike) , and if so
is there any explanation for how that works (I did read something about
"stress corrosion" in the archives).
Ben C
>> On 2006-11-17, jobst....@stanfordalumni.org <jobst....@stanfordalumni.org> wrote:
>>> Ben C? writes:
[snip]
>> with a force of 900N (the wheel is in the truing stand for the sake of
>> argument, or floating around in an orbiting spacecraft, it doesn't
>> matter). The rim can withstand 900N and so doesn't crack. But over time
>> as the rim wears, it reaches a point where it can only withstand 890N,
>> so it cracks.
>
> can't say that. the rim doesn't wear in the section that has the point
> contact load, so you're not going to see yield decrease over time.
> fatigue properties depend on how far along the s-n graph you are.
>
>> But if the spoke had only been at 850N tension all along,
>> perhaps the rim would last a bit longer,
>
> perhaps, but...
>
>> assuming the rate of wear at
>> 850N and 900N were about the same,
>
> not as a function of wear!
>
>> which may be a false assumption.
>
> indeed, if you base it on wear. fatigue life is another matter, and may
> indeed be mitigated by lower tension.
I was using the word "wear" in a general sense, not being an engineer. I
suppose wear is strictly what you get when things rub together in some
way, i.e. what happens on a rim where the brake blocks touch it? And
fatigue is the process by which if you bend a teaspoon backwards and
forwards a few times it breaks.
>> This might be a reason for building wheels tight enough but not too
>> tight.
> build to rim manufacturer spec. no less, no more.
This sounds like the best advice. But it's interesting to know what the
reasons are.
jim beam
yes, the rim wears where the brake pads touch, but that wear doesn't
impact the region around the eyelets so they retain strength until they
start to fatigue.
> And
> fatigue is the process by which if you bend a teaspoon backwards and
> forwards a few times it breaks.
technically, the bending spoon is referred to as "low cycle fatigue" and
is essentially where the material "runs out of ductility". the
mechanism for high cycle fatigue is completely different.
there's many articles on fatigue available on the web, but here's a good
starter:
http://www.sv.vt.edu/classes/MSE2094_NoteBook/97ClassProj/anal/kelly/fatigue.html
>
>>> This might be a reason for building wheels tight enough but not too
>>> tight.
>
>> build to rim manufacturer spec. no less, no more.
>
> This sounds like the best advice. But it's interesting to know what the
> reasons are.
basically, excess tension simply over-loads the rim in the contact
points, where the spokes connect. they can take a certain amount of
load reliably, but exceed that, and failure becomes inevitable.
jim beam
indeed. all those tensions are in the same ballpark as those quoted for
32 or 36 spoke standard rims. the cosmos at 90kg has only 24 spokes -
presumably a function of the lesser grade 6061 alloy than their other
rim alloy, "maxtal", [whatever that is] that's used in the ksyrium series.
>
> [snip]
>>> or go slack and allow
>>> spoke nipples to unscrew for which glue has become popular.
>> so what? it works, and works well. and more moderate tension prevents
>> rims from cracking.
>
> Are there any other harmful sideeffects of spokes going completely slack
> besides just the nipples unscrewing?
>
> For example, these are the things I'm concerned about:
>
> 1. increased fatigue around the nipple because of higher deflection.
rare.
> 2. the top spokes increasing in tension beyond the original pretension
> because the load exceeds the pretension of the bottom spokes (they go
> completely slack).
spoke tension increases slightly, but truth is, the rim is flexible and
the load is distributed among all the spokes, so the combined effect is
that tension doesn't increase specifically at the top and won't kill
spokes on its own. spoke tension increases much more under lateral
loads like when you honk up a hill.
> 3. increased fatigue of the spokes themselves, perhaps around the elbow,
> because they are actually being bent slightly in compression, leading
> them to break.
they don't compress - this is wire, it bends first. but you /do/ get a
lot more flexing, and that does indeed fatigue spoke elbows.
>
>>>> Do people usually see cracked eyelets on the drive side or on the
>>>> non-drive side of rear wheels? Maybe this would be an indicator of
>>>> whether high tension or low tension wears the rim more at the
>>>> eyelets.
>>> They see them on both sides and front wheels.
>> on rims with excessive tension, yes. on rims with more moderated
>> tension, the only time they're seen, [if at all] is on the drive side
>> rear - where tension increases due to the low bracing angle are
>> significant. you know that tension increase is a function of 1/sin
>> theta, right?
>
> So are you saying excessive tension does actually promote cracking
> around the eyelets in use (as opposed to the cracks appearing in the
> truing stand before the wheel's even been put on the bike)
yes. you're raising the mean load, then cycling stress from there.
that increases fatigue considerably.
> , and if so
> is there any explanation for how that works (I did read something about
> "stress corrosion" in the archives).
>
> http://tinyurl.com/u753r
stress corrosion may indeed be a factor because the rim cracking
commonly seen typically follows extrusion lines well away from the
loading zone.