Recommended Spoke Tension for DT Swiss XR 4.1d rim

[Andrew Price]

On 11 Sep 2007 22:50:57 GMT, [email protected] wrote:

>To see how
>destructive a Stasi (or CIA) can be, see:
>
>http://www.calendarlive.com/movies/reviews/cl-et-lives1dec01,0,2952621.story

That is a great film.

>The brutality is all mental, but the human destruction total; done
>only with words! How could that hurt?
>
>I'm curious how the showing of the film was delayed coming to the USA
>for nearly a year while being show in the rest of the world.
>Thereafter it appeared mostly in smaller "art cinemas" here.

A sad additional piece of information is that its main protagonist,
Ulrich Mühe, died last July at the early age of 54.

 

[Jambo]

<[email protected]> wrote in message
news:[email protected]...
> Lou Holtman writes:
>> Thanks Mr. Brandt for explaining this again and again. What
>> strikes me is the amount of attention spokes, wheels, rims get in
>> RBT and every discussion ends in name calling and people getting
>> personal in a very nasty way. And guess what, me and all my riding
>> buddies had any problems with our wheels for years and years. So I
>> wonder 'what is all this fuss about'. 'Maybe it is something of the
>> 'new world'.
......

> Others who felt similarly have been attacking the book ever since.
> More recently civility in discourse has been eroded on RBT. People no
> longer "disagree" they reply with rude rejoinders, not realizing that
> these discredit what they say. This tone has permeated our society
> from high places in the USA that attack people's honesty and
> patriotism for expressing disagreement. We have lost community in
> this era and it may not return for a long time.

Maybe it has to do with all the TV "reality" shows that portray no reality
at all, but rather the worst excesses of tabloid commercial TV in pursuit of
ratings.

Maybe it has to do with fear and insecurity, that letting other people have
different views will "let the terrorists win".

Or maybe it has to do with the need of some people to be acknowledged in
some way as having something to contribute, even though their bleating
really has nothing to do with advancing knowldege, but rather to gain their
15 minutes of fame (or infamy - beamboy, you reading this?).

Regardless, when people like beamboy go to great lengths to manufacture an
identity, manufacture contrarian ideas with manufactured and contrived
"data", and to devote a major part of their lives in perpetuating fraudulent
ideologies as means of defining their identity, and society (through popular
culture) saying this is okay, we're indeed headed for dark times.

 

[Ron Ruff]

On Sep 12, 1:35 pm, "Jambo" <[email protected]> wrote:
> Maybe it has to do with fear and insecurity, that letting other people have
> different views will "let the terrorists win".

The "War on Terror" and the "terrorists winning" are one and the
same... ie when we decided to wage the war, that is when we lost...

Nice film, "The Lives of Others". There was a comment made in the film
that 20 years ago people would have never tolerated what was going on,
but now they were used to it. And we are slowly getting used to it as
well.

 

[Peter Cole]

Ron Ruff wrote:
> On Sep 12, 1:35 pm, "Jambo" <[email protected]> wrote:
>> Maybe it has to do with fear and insecurity, that letting other people have
>> different views will "let the terrorists win".
>
> The "War on Terror" and the "terrorists winning" are one and the
> same... ie when we decided to wage the war, that is when we lost...
>
> Nice film, "The Lives of Others". There was a comment made in the film
> that 20 years ago people would have never tolerated what was going on,
> but now they were used to it. And we are slowly getting used to it as
> well.

Just when I'm thinking I've grown too cynical I discover I'm not cynical
enough (again).

I do believe there are some absolutes. The end never justifies the means
-- here, there or anywhere.

 

[jim beam]

Chalo wrote:
> Qui si parla Campagnolo-www.vecchios.com wrote:
>> If I were building a 900 gram downhill rim with 13/14g spokes, the
>> tension would be higher because the application is tougher on the
>> wheel, the rim is stronger..nothing to do with the
>> spokes...
>
> You are right that the rim's strength (and sometimes spoke count)
> determine the tension to use, but the tension determines what spokes
> will be appropriate.
>
> For a rim with "too many" spoke holes for its weight, like the 48h Sun
> CR-18, the spoke tension may have to be less than 100kgf to keep the
> rim from buckling (I haven't measured the exact value, just observed
> the phenomenon while tensioning wheels). if the tension is less than
> 100kgf, then 1.6mm or 1.5mm spokes will work better than thicker ones;
> they'll be less likely to go slack.
>
> For a rim with a heavy section and few spoke holes, the tension should
> be a lot higher than 100kgf.

that's not true. tension on my 16 spoke heavy section shimano r540's is
about the same as a standard 32 spoke wheel. from factory.


> 16 spoke road wheels with aero rims are
> a good example-- don't those suckers need almost 200kgf of spoke
> tension?

nope.

 

[Chalo]

jim beam wrote:
>
> Chalo wrote:
>
> > For a rim with a heavy section and few spoke holes, the tension should
> > be a lot higher than 100kgf.
>
> that's not true. tension on my 16 spoke heavy section shimano r540's is
> about the same as a standard 32 spoke wheel. from factory.
>
> > 16 spoke road wheels with aero rims are
> > a good example-- don't those suckers need almost 200kgf of spoke
> > tension?
>
> nope.

Well, I just downloaded the owner's manual for Bontrager package
wheels, and for their Race X-Lite Aero (which I assume is a low spoke
count wheel) and Race X-Lite Aero Carbon, they spec up to 400 lbf
tension.

I found a Park Tool page that gave the spec for the Mavic Ksyrium
Elite as up to 160 kgf. For what it's worth, it specs the Shimano
R540 at 98-118kgf in front and 105-128 kgf in the rear-- relatively
normal, just as you claim.

The spec for other wheels starts at 50 kgf for front wheel spokes and
ranges to 181 for rear wheel spokes, so there's no indication that 100
kgf is the right tension for all purposes. It looks like 100 kgf
would be within spec for at least half the listed wheels, though.

It's worth pointing out that all the listed wheels are for bikes with
some kind of sporting pretensions, and none of them have high spoke
counts. So for wheels in the real world whose uses require more of
them than play bikes do, I'd expect to see a correspondingly wider
range of appropriate spoke tensions depending on spoke count, rim
section, and intended load.

For what it's worth, Park says this: "The recommended tension for
spokes in bicycle wheels can be as low as 80 Kilograms force (Kfg) and
as high as 230 Kilograms force. As a rule of thumb, it is best to set
tension as high as the weakest link in the system will allow, which
for a bicycle wheel is usually the rim." That sounds like something
Jobst would say.

http://parktool.com/repair/readhowto.asp?id=51

Chalo

 

[Qui si parla Campagnolo-www.vecchios.com]

On Sep 12, 9:24 am, Chalo <[email protected]> wrote:
> Qui si parla Campagnolo-www.vecchios.comwrote:
>
>
>
> > If I were building a 900 gram downhill rim with 13/14g spokes, the
> > tension would be higher because the application is tougher on the
> > wheel, the rim is stronger..nothing to do with the
> > spokes...
>
> You are right that the rim's strength (and sometimes spoke count)
> determine the tension to use, but the tension determines what spokes
> will be appropriate.
>
> For a rim with "too many" spoke holes for its weight, like the 48h Sun
> CR-18, the spoke tension may have to be less than 100kgf to keep the
> rim from buckling (I haven't measured the exact value, just observed
> the phenomenon while tensioning wheels). if the tension is less than
> 100kgf, then 1.6mm or 1.5mm spokes will work better than thicker ones;
> they'll be less likely to go slack.
>
> For a rim with a heavy section and few spoke holes, the tension should
> be a lot higher than 100kgf. 16 spoke road wheels with aero rims are
> a good example-- don't those suckers need almost 200kgf of spoke
> tension?
>
> Chalo

I have built a few Deep V, radial, bladed, 16 and 18h and the tension
was still in the 100-110kgf range, front wheels. Ditto for some Deep
V, 24h, 2 cross rears..samo-

 

[jim beam]

Chalo wrote:
> jim beam wrote:
>> Chalo wrote:
>>
>>> For a rim with a heavy section and few spoke holes, the tension should
>>> be a lot higher than 100kgf.
>> that's not true. tension on my 16 spoke heavy section shimano r540's is
>> about the same as a standard 32 spoke wheel. from factory.
>>
>>> 16 spoke road wheels with aero rims are
>>> a good example-- don't those suckers need almost 200kgf of spoke
>>> tension?
>> nope.
>
> Well, I just downloaded the owner's manual for Bontrager package
> wheels, and for their Race X-Lite Aero (which I assume is a low spoke
> count wheel) and Race X-Lite Aero Carbon, they spec up to 400 lbf
> tension.

gotta use consistent units of measurements! 400lbf = 182kgf.

>
> I found a Park Tool page that gave the spec for the Mavic Ksyrium
> Elite as up to 160 kgf.

park say? what do mavic say? do mavic use that from factory?

> For what it's worth, it specs the Shimano
> R540 at 98-118kgf in front and 105-128 kgf in the rear-- relatively
> normal, just as you claim.

and i'll bet that shimano have never read "the book" so their
engineering is untainted.

>
> The spec for other wheels starts at 50 kgf for front wheel spokes and
> ranges to 181 for rear wheel spokes, so there's no indication that 100
> kgf is the right tension for all purposes. It looks like 100 kgf
> would be within spec for at least half the listed wheels, though.
>
> It's worth pointing out that all the listed wheels are for bikes with
> some kind of sporting pretensions, and none of them have high spoke
> counts. So for wheels in the real world whose uses require more of
> them than play bikes do, I'd expect to see a correspondingly wider
> range of appropriate spoke tensions depending on spoke count, rim
> section, and intended load.
>
> For what it's worth, Park says this: "The recommended tension for
> spokes in bicycle wheels can be as low as 80 Kilograms force (Kfg) and
> as high as 230 Kilograms force. As a rule of thumb, it is best to set
> tension as high as the weakest link in the system will allow, which
> for a bicycle wheel is usually the rim." That sounds like something
> Jobst would say.
>
> http://parktool.com/repair/readhowto.asp?id=51
>
> Chalo
>

i think it more interesting that the only one that is truly a high
tension wheel is domestic - and doubtless influenced by jobstian
misunderstanding. there really is no point in tension "as high as the
rim can bear". it achieves nothing for wheel strength, can increase rim
buckling and decreases fatigue life. tension needs to be as high as
necessary to prevent spoke slackness in use - no more.

 

[Ron Ruff]

On Sep 13, 6:59 am, jim beam <[email protected]> wrote:
> tension needs to be as high as
> necessary to prevent spoke slackness in use - no more.

I agree... but if your tension is lower than it *could* be then the
spokes will go slack at a lighter load than they would otherwise. So
if you wish to optimize a wheel's performance (low weight and drag),
you will reduce the number of spokes and increase the tension until
you are at the limit for at least one part of the system. Even if you
just want a standard wheel with 32-36 spokes, one with higher tension
will take a bigger load before spokes go slack... though in that case
you might get away with lower tension if the loads are not extreme.

 

[still me]

On Wed, 12 Sep 2007 18:13:33 -0400, Peter Cole
<[email protected]> wrote:

>I do believe there are some absolutes. The end never justifies the means
>-- here, there or anywhere.

Especially when the end is a fraud from the beginning.