spoke tension

Mark Felber said:

Could someone recommend the proper spoke tension for a rear wheel built
with a Velocity Aerohead OC rim?

JB says tension as high as the rim will bear without taking a "taco" or
"potato chip" shape; however, jb says tension only as high as the
manufacturer's recommendation, or the rim will crack around the spoke hole.

LET THE BATTLE BEGIN!

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

--
Posted via a free Usenet account from http://www.teranews.com

mark said:

Could someone recommend the proper spoke tension for a rear wheel built
with a Velocity Aerohead OC rim?

TIA,

mark

100 kgf for the right side. If true, round, dished..the left side
tension will take care of itself.

Thank you.

mark

Qui si parla Campagnolo said:

mark said:

Could someone recommend the proper spoke tension for a rear wheel built
with a Velocity Aerohead OC rim?

TIA,

mark

100 kgf for the right side. If true, round, dished..the left side
tension will take care of itself.

In article <[email hidden]>,

Qui si parla Campagnolo said:

mark said:

Could someone recommend the proper spoke tension for a rear wheel
built with a Velocity Aerohead OC rim?

100 kgf for the right side.

Which is pretty much the standard number used for the drive side of the
rear wheel and both sides of the front wheel for just about any wheel
with a normal number of spokes (32-36). Except for Mavic who recommend
95 kgf, according to previously published information.

Johnny Sunset aka Tom Sherman said:

Mark Felber said:

Could someone recommend the proper spoke tension for a rear wheel
built with a Velocity Aerohead OC rim?

JB says tension as high as the rim will bear without taking a "taco" or
"potato chip" shape; however, jb says tension only as high as the
manufacturer's recommendation, or the rim will crack around the spoke hole.

LET THE BATTLE BEGIN!

That's not really what Jobst says. It's what jim beam says Jobst says,
which are usually two (often very) different things. I guess you didn't
read the book, either.

quote='Peter Cole'Johnny Sunset aka Tom Sherman said:

Mark Felber said:

Could someone recommend the proper spoke tension for a rear wheel
built with a Velocity Aerohead OC rim?

JB says tension as high as the rim will bear without taking a "taco" or
"potato chip" shape; however, jb says tension only as high as the
manufacturer's recommendation, or the rim will crack around the spoke hole.

LET THE BATTLE BEGIN!

That's not really what Jobst says. It's what jim beam says Jobst says,
which are usually two (often very) different things. I guess you didn't
read the book, either.[/QUOTE]

Dear Peter,

Here's what Jobst wrote:

FINDING THE RIGHT TENSION
The following method works well in determining proper spoke tension for conventional road rims of up to 430 grams with 36 spokes. Tighten all the spokes a quarter turn at a time, starting at the valve stem hole. Once a distinct tone can be made by plucking, and spokes are not easily squeezed together by grasping them in pairs, it is time to check tension. After each round of tightening, test the tension by stress relieving. If the wheel becomes untrue in two large waves during stress relieving, the maximum, safe tension has been exceeded. Approach this tension carefully to avoid major rim distortions. When the wheel loses alignment from stress relieving, loosen all spokes a half turn before retruing the wheel.

Stress relieving, discussed in a following section, increases tension enough to overload the rim if the spokes are too tight. A strong and safe wheel should be able to withstand about a ten percent overload without damage. Note that tightening all spokes of an offset rear wheel will move the rim away from the right side as described under Wheels with Multiple Sprockets (page 100). Check centering and radial and lateral alignment again. Only small corrections, if any, should be required.

With large cross section mountain bike and deep section aero rims the tension of 36 spokes may not exceed the strength of the rim. For such heavy rims and conventional road rims using fewer than 32 spokes, tensioning is usually at the limit when the nipples can no longer be tightened easily.

--"The Bicycle Wheel," 3rd edition, p. 105

It should be noted that wheels are usually built with no tire. Inflating a 700c tire to 120 psi on a typical modern box-section rim causes the tire to constrict like a python around the rim and reduces 99 kgf spoke tension around ~15%:

geocities.comtension inflation.htmOpen ↗

Thus many road wheels are at lower practical tension than their builders realize.

On the other hand, inflating a tire on a wide no-box section rim can _increase_ spoke tension. The effect of the tire constricting the long way around the rim is swamped by the tire bulging sideways, spreading the vee of the rim, and drawing the spokes away from the hub:

groups.google.com81bd0e13a9a0797eOpen ↗

Cheers,

Carl Fogel

Peter Cole said:

Johnny Sunset aka Tom Sherman said:

Mark Felber said:

Could someone recommend the proper spoke tension for a rear wheel
built with a Velocity Aerohead OC rim?

JB says tension as high as the rim will bear without taking a "taco"
or "potato chip" shape; however, jb says tension only as high as the
manufacturer's recommendation, or the rim will crack around the spoke
hole.

LET THE BATTLE BEGIN!

That's not really what Jobst says. It's what jim beam says Jobst says,
which are usually two (often very) different things. I guess you didn't
read the book, either.

Well, I actually have read "The Bicycle Wheel" (but not recently). So
much for assumptions.

Do you deny that Jobst Brandt has stated that ONE of the methods for
determining maximum tension is that if the rim does NOT stay true when
stress relieving [1], the spokes are too tight?

[1] Not what happens according to jb.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

--
Posted via a free Usenet account from http://www.teranews.com

Johnny Sunset aka Tom Sherman said:

Do you deny that Jobst Brandt has stated that ONE of the methods for
determining maximum tension is that if the rim does NOT stay true when
stress relieving [1], the spokes are too tight?

My (third printing, 1985) copy of The Bicycle wheel says:

"When maximum tension is reached the wheel will not remain true after
stress relieving. This tension should be approached carefully to avoid
rim damage. When the wheel begins to deform upon stress relieving, all
spokes should be loosened half a turn and the wheel re-trued."

mark

Peter Cole said:

Johnny Sunset aka Tom Sherman said:

Mark Felber said:

Could someone recommend the proper spoke tension for a rear wheel
built with a Velocity Aerohead OC rim?

JB says tension as high as the rim will bear without taking a "taco"
or "potato chip" shape; however, jb says tension only as high as the
manufacturer's recommendation, or the rim will crack around the spoke
hole.

LET THE BATTLE BEGIN!

That's not really what Jobst says. It's what jim beam says Jobst says,
which are usually two (often very) different things. I guess you didn't
read the book, either.

"as high as the rim can bear" is what jobst says on this group.

"spokes must be as tight as the rim permits" is what he says in "the
book". [3rd edition.]

either way, he equates increasing spoke tension with increasing wheel
strength: "a wheel with spoke tension near the limit of rim strength can
support large loads easily" - which is untrue, misleading and reveals
gross misunderstanding.

urlhttp://www.jimbeam.com/beam/default.aspx?/url said:

Quoted message said:

Quoted message said:

> Could someone recommend the proper spoke tension for a rear wheel
> built with a Velocity Aerohead OC rim?

Quoted message said:

Quoted message said:

Quoted message said:

JB says tension as high as the rim will bear without taking a
"taco" or "potato chip" shape; however, jb says tension only as
high as the manufacturer's recommendation, or the rim will crack
around the spoke hole.

Quoted message said:

Quoted message said:

Quoted message said:

LET THE BATTLE BEGIN!

Quoted message said:

Quoted message said:

That's not really what Jobst says. It's what jim beam says Jobst
says, which are usually two (often very) different things. I guess
you didn't read the book, either.

Quoted message said:

"as high as the rim can bear" is what jobst says on this group.

Quoted message said:

"spokes must be as tight as the rim permits" is what he says in "the
book". [3rd edition.]

Quoted message said:

either way, he equates increasing spoke tension with increasing
wheel strength: "a wheel with spoke tension near the limit of rim
strength can support large loads easily" - which is untrue,
misleading and reveals gross misunderstanding.

I think such statements need a bit of evidence to be credible.

A wire spoked bicycle wheel can carry loads up to the point where its
spokes become slack from compression as they pass the load point on
the road. The looser the spokes the more easily this occurs and
conversely the tighter the spoke the less this occurs.

I have ridden many 100k miles with wheels tensioned as described
without needing to re-true them or to replace cracked rims. These
have been socketed tubular rims (Fiamme, Super Champion, and Mavic)
and Super Champion "Gentleman" and Mavic MA-2 clincher rims. I still
ride the latter as do most of my fellow riders, ones who do not see
themselves as professional like racers..

When riding rough roads such as described in rec.bicycles.rides "Last
chance road", I and my bikie friends wonder if the light weight "with
it" crowd ever experience roads that are demanding on 36-spoke wheels.

http://tinyurl.com/2uc6tb

Dings in rims also come from insufficient inflation, a parallel to
insufficient spoke tension in supporting loads.

http://geocities.com/rayhosler/slideshow.html

Ride bike!

Jobst Brandt

aka Jobst Brandt said:

...
Dings in rims also come from insufficient inflation...

During the Weimar Republic era, German riders found their rims
impervious to damage from potholes and other impacts.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

--
Posted via a free Usenet account from http://www.teranews.com

Quoted message said:

urlhttp://www.jimbeam.com/beam/default.aspx?/url said:

Quoted message said:

>> Could someone recommend the proper spoke tension for a rear wheel
>> built with a Velocity Aerohead OC rim?

Quoted message said:

Quoted message said:

> JB says tension as high as the rim will bear without taking a
> "taco" or "potato chip" shape; however, jb says tension only as
> high as the manufacturer's recommendation, or the rim will crack
> around the spoke hole.

Quoted message said:

Quoted message said:

> LET THE BATTLE BEGIN!

Quoted message said:

Quoted message said:

That's not really what Jobst says. It's what jim beam says Jobst
says, which are usually two (often very) different things. I guess
you didn't read the book, either.

Quoted message said:

"as high as the rim can bear" is what jobst says on this group.

Quoted message said:

"spokes must be as tight as the rim permits" is what he says in "the
book". [3rd edition.]

Quoted message said:

either way, he equates increasing spoke tension with increasing
wheel strength: "a wheel with spoke tension near the limit of rim
strength can support large loads easily" - which is untrue,
misleading and reveals gross misunderstanding.

I think such statements need a bit of evidence to be credible.

A wire spoked bicycle wheel can carry loads up to the point where its
spokes become slack from compression as they pass the load point on
the road. The looser the spokes the more easily this occurs and
conversely the tighter the spoke the less this occurs.

as discussed on several prior occasions, you are only considering the
spokes, not the rim. increasing spoke tension increases circumferential
rim compression. but you miss the point that as the rim's compression
rises, its load capacity decreases.

let's assume an aluminum beam has the same tensile strength as it does
compression. let's say that it yields at [pick a number] +/- 100Mpa.
in plain bending, the compressive side yields at the same time as the
tensile side - when this limit is reached. now, compress the beam
longitudinally at say 50Mpa, i.e. superimpose a stress on it. the
tensile side of the beam can now support 100 + 50 = 150Mpa before yield.
but the compressive side can only support 100 - 50 = 50Mpa. so if i
bend it now, the beam will start to yield supporting only half the load
it did before.

with materials with no tensile strength like concrete, you "borrow" from
the material's [ample] compressive strength to give it pseudo tensile
strength. but with a material as strong in compression as tension, like
an aluminum bike rim, that's simply counter-productive.

in your book, you also argue that rims collapse as soon as spokes go
slack go slack....
http://www.flickr.com/photos/38636024@N00/417157612/

writing a book is one thing. understanding what to put in it is quite
another.

Quoted message said:

I have ridden many 100k miles with wheels tensioned as described
without needing to re-true them or to replace cracked rims. These
have been socketed tubular rims (Fiamme, Super Champion, and Mavic)
and Super Champion "Gentleman" and Mavic MA-2 clincher rims. I still
ride the latter as do most of my fellow riders, ones who do not see
themselves as professional like racers..

When riding rough roads such as described in rec.bicycles.rides "Last
chance road", I and my bikie friends wonder if the light weight "with
it" crowd ever experience roads that are demanding on 36-spoke wheels.

http://tinyurl.com/2uc6tb

Dings in rims also come from insufficient inflation, a parallel to
insufficient spoke tension in supporting loads.

http://geocities.com/rayhosler/slideshow.html

Ride bike!

red herring.

jim beam' ? said:

...
in your book, you also argue that rims collapse as soon as spokes go
slack go slack....
http://www.flickr.com/photos/38636024@N00/417157612/

How far did you ride on that wheel?

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

--
Posted via a free Usenet account from http://www.teranews.com

On Wed, 18 Jul 2007 03:12:24 GMT, mark <[email hidden]>

Quoted message said:

Johnny Sunset aka Tom Sherman said:

Do you deny that Jobst Brandt has stated that ONE of the methods for
determining maximum tension is that if the rim does NOT stay true when
stress relieving [1], the spokes are too tight?

My (third printing, 1985) copy of The Bicycle wheel says:

"When maximum tension is reached the wheel will not remain true after
stress relieving. This tension should be approached carefully to avoid
rim damage. When the wheel begins to deform upon stress relieving, all
spokes should be loosened half a turn and the wheel re-trued."

mark

Dear Mark,

I posted the following earlier in reply to Peter Cole, but it doesn't
seem to show up outside of cyclingforums, so here it is again. I'm
tacking it on to your post, since they're related and I can't get at
earlier posts, with Google down and cyclingforums not propagating. The
lengthy quote is from the 3rd edition of 1993, rather than the 3rd
printing of an earlier edition.

Here's what Jobst wrote:

FINDING THE RIGHT TENSION
The following method works well in determining proper spoke tension
for conventional road rims of up to 430 grams with 36 spokes. Tighten
all the spokes a quarter turn at a time, starting at the valve stem
hole. Once a distinct tone can be made by plucking, and spokes are not
easily squeezed together by grasping them in pairs, it is time to
check tension. After each round of tightening, test the tension by
stress relieving. If the wheel becomes untrue in two large waves
during stress relieving, the maximum, safe tension has been exceeded.
Approach this tension carefully to avoid major rim distortions. When
the wheel loses alignment from stress relieving, loosen all spokes a
half turn before retruing the wheel.

Stress relieving, discussed in a following section, increases tension
enough to overload the rim if the spokes are too tight. A strong and
safe wheel should be able to withstand about a ten percent overload
without damage. Note that tightening all spokes of an offset rear
wheel will move the rim away from the right side as described under
Wheels with Multiple Sprockets (page 100). Check centering and radial
and lateral alignment again. Only small corrections, if any, should be
required.

With large cross section mountain bike and deep section aero rims the
tension of 36 spokes may not exceed the strength of the rim. For such
heavy rims and conventional road rims using fewer than 32 spokes,
tensioning is usually at the limit when the nipples can no longer be
tightened easily.

--"The Bicycle Wheel," 3rd edition, p. 105

It should be noted that wheels are usually built with no tire.
Inflating a 700c tire to 120 psi on a typical modern box-section rim
causes the tire to constrict like a python around the rim and reduces
99 kgf spoke tension around ~15%:

http://www.geocities.com/dianne_1234/bikes/tension-inflation/tension-inflation.htm

Thus many road wheels are at lower practical tension than their
builders realize.

On the other hand, inflating a tire on a wide no-box section rim can
_increase_ spoke tension. The effect of the tire constricting the long
way around the rim is swamped by the tire bulging sideways, spreading
the vee of the rim, and drawing the spokes away from the hub:

http://groups.google.com/group/rec.bicycles.tech/msg/81bd0e13a9a0797e

Cheers,

Carl Fogel

Mark Felber said:

Johnny Sunset aka Tom Sherman said:

Do you deny that Jobst Brandt has stated that ONE of the methods for
determining maximum tension is that if the rim does NOT stay true when
stress relieving [1], the spokes are too tight?

My (third printing, 1985) copy of The Bicycle wheel says:

"When maximum tension is reached the wheel will not remain true after
stress relieving. This tension should be approached carefully to avoid
rim damage. When the wheel begins to deform upon stress relieving, all
spokes should be loosened half a turn and the wheel re-trued."

Exactly the passage I was referring to (from memory).

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

--
Posted via a free Usenet account from http://www.teranews.com

mark said:

Thank you.

mark

Qui si parla Campagnolo said:

mark said:

Could someone recommend the proper spoke tension for a rear wheel built
with a Velocity Aerohead OC rim?

Quoted message said:

Quoted message said:

TIA,

Quoted message said:

Quoted message said:

mark

Quoted message said:

100 kgf for the right side. If true, round, dished..the left side
tension will take care of itself.

Happy to help-email direct or on this NG if you have anyother ?.

Johnny Sunset aka Tom Sherman said:

jim beam' ? said:

...
in your book, you also argue that rims collapse as soon as spokes go
slack go slack....
http://www.flickr.com/photos/38636024@N00/417157612/

How far did you ride on that wheel?

as far as i could without the tensiometer falling off... wise guy.

how about you address the point of the posting: "...the wheel can
support loads only to the point where its spokes become loose. at this
point the wheel will collapse." jobst brandt. "the book". 3rd edition.

mark said:

Johnny Sunset aka Tom Sherman said:

Do you deny that Jobst Brandt has stated that ONE of the methods for
determining maximum tension is that if the rim does NOT stay true when
stress relieving [1], the spokes are too tight?

My (third printing, 1985) copy of The Bicycle wheel says:

"When maximum tension is reached the wheel will not remain true after
stress relieving. This tension should be approached carefully to avoid
rim damage. When the wheel begins to deform upon stress relieving, all
spokes should be loosened half a turn and the wheel re-trued."

random and arbitrary rubbish. "hey, how much load can that old wooden
bridge support? dunno, let's drive across it and find out."

Johnny Sunset aka Tom Sherman said:

aka Jobst Brandt said:

...
Dings in rims also come from insufficient inflation...

During the Weimar Republic era, German riders found their rims
impervious to damage from potholes and other impacts.

Or so they reported. But of course we can never really know der ding an
sich.