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Date: 10 Sep 2007 13:45:04
From: Simon
Subject: Spoke tension in numbers
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Hi
I've just finished building a brend new rear wheeel for my touring
bike.
I've used Jobst Brandt and the Gerd Schraner books as references. I've
used a home made truing stand with dial gauges, a dishing stick and a
Park tensiometer.
The final result is excellent.
I didn't mange to find any indication about spoke tension racomanded
values neither in Brandt nor Schraner book. I guess those values
depend on rim model and brands but I could not find any of those
indications on producers web sites or catalogues.The only reference
I've found is in the Park tensiometer instruction sheet but there's no
mention about different rim model or brands.
My whee has 36 dt spokes 1,8/2.0 mm mounted on a Mavic A719 rim, I've
tigh the sprocket side of the wheel to 110 Kilograms force (kgf) on
the Park scale.
Is there somebody who knows what's the racomanded spoke tension for
this mavic rim?
thanks
simone
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Date: 14 Sep 2007 05:09:02
From: Simon
Subject: Re: Spoke tension in numbers
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Thanks
I should have read the text more carefully before writing
simone tofani
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Date: 13 Sep 2007 06:17:48
From: Simon
Subject: Re: Spoke tension in numbers
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> "the Bicycle Wheel" describes a method of determining proper tension,
> and it is, as you say, dependent on the rim and number of spokes.
> Check under "stress relieving" in "the Bicycle Wheel".
>
> Jobst Brandt
Thank you very much for your replay.
I read again the metod you suggest in your book for determining proper
spoke tension.
I wonder if recognising the structure limit by getting the wheel
suddenly untrued while tightening spokes were healthy for the rim and
spokes. I thought that this sudden change in the wheel (to get the
wheel untrued) would be a sign of an irreversible change in one of the
components of the wheel (rim spokes nipples) as passing a fatigue
limit.
Simone Tofani
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Date: 13 Sep 2007 18:38:06
From:
Subject: Re: Spoke tension in numbers
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Simon Tofani writes:
>> "the Bicycle Wheel" describes a method of determining proper
>> tension, and it is, as you say, dependent on the rim and number of
>> spokes.
>> Check under "stress relieving" in "the Bicycle Wheel".
> Thank you very much for your replay.
> I read again the method you suggest in your book for determining
> proper spoke tension.
> I wonder if recognising the structure limit by getting the wheel
> suddenly untrue while tightening spokes were healthy for the rim and
> spokes. I thought that this sudden change in the wheel (to get the
> wheel untrue) would be a sign of an irreversible change in one of
> the components of the wheel (rim spokes nipples) as passing a
> fatigue limit.
The wheel doesn't "getting the wheel suddenly untrue". The effect is
that after stress relieving the wheel is less true than before in a
four lobe shape. There is no damage to the rim and that is also dealt
with in the text.
As I have mentioned, My hubs and spokes in the wheels I used for
300,000 miles were built by that method, the rims wore out a few times
while some got damaged beyond repair in crashes. Your concern of
damaging components by this method is not supported by experience. At
the time that I devised this method, rim manufacturers had not yet
prescribed tension.
A side "experiment" done by a friends occurred when he built a new
rear wheel before a long group ride. After climbing a steep mountain
road and before descending the other side of the mountain, I rode
behind him noting that his wheels were true. However, after the first
hard braking his rear wheel had the classic taco shape because he had
not stress relieved and found it to be too tight.
It was from this experience that I recognized the secondary benefit of
stress relieving. That of assessing safe maximum tension. We
adjusted his spokes and rode additional 100 miles that day without a
problem. The wheel served well for many miles thereafter.
Jobst Brandt
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Date: 10 Sep 2007 22:32:07
From:
Subject: Re: Spoke tension in numbers
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Simone Tofani writes:
> I've just finished building a brand new rear wheel for my touring
> bike. I've used Jobst Brandt and the Gerd Schraner books as
> references. I've used a home made truing stand with dial gauges, a
> dishing stick and a Park tensiometer. The final result is
> excellent.
I hope your wheel also serves you excellently. Time (distance) will
tell.
> I didn't mange to find any indication about spoke tension
> recommended values neither in Brandt nor Schraner book. I guess
> those values depend on rim model and brands but I could not find any
> of those indications on producers web sites or catalogues. The only
> reference I've found is in the Park tensiometer instruction sheet
> but there's no mention about different rim model or brands.
"the Bicycle Wheel" describes a method of determining proper tension,
and it is, as you say, dependent on the rim and number of spokes.
> My wheel has 36 DT spokes 1,8/2.0 mm mounted on a Mavic A719 rim,
> I've tightened the sprocket side of the wheel to 110 Kilograms force
> (kgf) on the Park scale.
That already sounds like a good value. Next time you build, try
1.6-1.8mm spokes for the reasons mentioned in the book. Anyway, this
rim has sockets and eyelets, supporting spoke loads on its inner and
outer wall, so it is not as prone to cracking as many rims that have
their spoke load resting only on the eyelet of the outer wall.
> Is there somebody who knows what's the recommended spoke tension for
> this Mavic rim?
Check under "stress relieving" in "the Bicycle Wheel".
Jobst Brandt
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Date: 10 Sep 2007 22:16:07
From:
Subject: Re: Spoke tension in numbers
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Simone Tofani writes:
> I've just finished building a brand new rear wheel for my touring
> bike. I've used Jobst Brandt and the Gerd Schraner books as
> references. I've used a home made truing stand with dial gauges, a
> dishing stick and a Park tensiometer. The final result is
> excellent.
I hope your wheel also serves you excellently. Time (distance) will
tell.
> I didn't mange to find any indication about spoke tension
> recommended values neither in Brandt nor Schraner book. I guess
> those values depend on rim model and brands but I could not find any
> of those indications on producers web sites or catalogues. The only
> reference I've found is in the Park tensiometer instruction sheet
> but there's no mention about different rim model or brands.
"the Bicycle Wheel" describes a method of determining proper tension,
and it is, as you say, dependent on the rim and number of spokes.
> My wheel has 36 DT spokes 1,8/2.0 mm mounted on a Mavic A719 rim,
> I've tightened the sprocket side of the wheel to 110 Kilograms force
> (kgf) on the Park scale.
That already sounds like a good value. Next time you build, try
1.6-1.8mm spokes for the reasons mentioned in the book. Anyway, this
rim has sockets and eyelets, supporting spoke loads on its inner and
outer wall, so it is not as prone to cracking as many rims that have
their spoke load resting only on the eyelet of the outer wall are.
> Is there somebody who knows what's the recommended spoke tension for
> this Mavic rim?
Check under "stress relieving" in "the Bicycle Wheel".
Jobst Brandt
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Date: 10 Sep 2007 14:07:05
From: Simon
Subject: Re: Spoke tension in numbers
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On Sep 10, 10:49 pm, "mark" <markfel...@gmail.com > wrote:
> e-mail the US importer for Mavic or contact whoever sold you the rim, they
> should be willing to send you the correct figures. I believe 110 kg-f on the
> drive side is pretty generic, though.
>
> --
> mark
Thanks Mark
When you say "I believe 110 kg-f on the drive side is pretty generic"
you mean it's an average right value for drive side?
simone
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Date: 10 Sep 2007 14:49:57
From: mark
Subject: Re: Spoke tension in numbers
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e-mail the US importer for Mavic or contact whoever sold you the rim, they
should be willing to send you the correct figures. I believe 110 kg-f on the
drive side is pretty generic, though.
--
mark
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