Why heavier gauge drive side spokes?



I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
wheels. What are the reasons for and advisability of using heavier,
e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
use all 14/17/14's.

Any and all comments will be appreciated -- except from that one
disruptive and often in error, orifice of RBT, oracle of RBT
wannabe, 'even if they don't know, i know their spokes are ground and
polished, guy.

--

Spike
 
T

tiborg

Guest
Are you breaking the spokes on your current wheel?
How many and what type of spokes are you currently using?
Will you be using the new wheel for a different set of riding
conditions?

On Aug 8, 6:21 pm, [email protected] wrote:
> I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
> wheels. What are the reasons for and advisability of using heavier,
> e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
> Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
> use all 14/17/14's.
>
> Any and all comments will be appreciated -- except from that one
> disruptive and often in error, orifice of RBT, oracle of RBT
> wannabe, 'even if they don't know, i know their spokes are ground and
> polished, guy.
>
> --
>
> Spike
 
On Aug 8, 5:34 am, tiborg <[email protected]> wrote:
> Are you breaking the spokes on your current wheel?
> How many and what type of spokes are you currently using?
> Will you be using the new wheel for a different set of riding
> conditions?
>
> On Aug 8, 6:21 pm, [email protected] wrote:
>
> > I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
> > wheels. What are the reasons for and advisability of using heavier,
> > e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
> > Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
> > use all 14/17/14's.

>
> > Any and all comments will be appreciated -- except from that one
> > disruptive and often in error, orifice of RBT, oracle of RBT
> > wannabe, 'even if they don't know, i know their spokes are ground and
> > polished, guy.

>
> > --

>
> > Spike


My current wheelset is the first that I built and has just 3500 miles
on it. It uses 32 hole Mavic Reflex rims with DT 14/17/14 gauge
spokes except for 14/15/14 on the rear drive side. It is used for
general road use and has remained true and without spoke breakage so
far. This second set, with Ambrosio Nemesis rims, will be used under
the same conditions.

--

Spike
 
Q

Qui si parla Campagnolo-www.vecchios.com

Guest
On Aug 8, 3:21 am, [email protected] wrote:
> I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
> wheels. What are the reasons for and advisability of using heavier,
> e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
> Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
> use all 14/17/14's.
>
> Any and all comments will be appreciated -- except from that one
> disruptive and often in error, orifice of RBT, oracle of RBT
> wannabe, 'even if they don't know, i know their spokes are ground and
> polished, guy.
>
> --
>
> Spike


Support of the rim is essential and thin, thin spokes don't do that
well on the drive side.
 
A

Art Harris

Guest
"Spike" wrote:
> I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
> wheels. What are the reasons for and advisability of using heavier,
> e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
> Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
> use all 14/17/14's.
>


The right side spokes are under nearly twice the tension of left side
spokes. Since left side spokes are under less tension, they are more
likely to go slack under load, causing the wheel to go out of true.

Thinner spokes on the left are more elastic, and are less likely to go
slack.

What do you expect to gain by using 14/17/14 spokes?

Art Harris
 
J

jim beam

Guest
[email protected] wrote:
> I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
> wheels. What are the reasons for and advisability of using heavier,
> e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
> Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
> use all 14/17/14's.


tension increase is proportional to 1/sin theta, the bracing angle. that
means the shallower angle on the drive side gets more tension increase -
and therefore more stretch [and lateral deflection] with skinny spokes.

>
> Any and all comments will be appreciated -- except from that one
> disruptive and often in error, orifice of RBT, oracle of RBT
> wannabe, 'even if they don't know, i know their spokes are ground and
> polished, guy.


buy a microscope, guy.
 
C

Chalo

Guest
[email protected] wrote:
>
> I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
> wheels. What are the reasons for and advisability of using heavier,
> e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
> Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
> use all 14/17/14's.


On 10-speed rear hubs, the center-to-flange dimension on the right is
about 1/3 of that on the left. Roughly speaking, that means spoke
tension must be three times higher on the right than it is on the
left, and that side loads on the wheel have three times more
mechanical advantage when they pull on right side spokes.

There are two main reasons you shouldn't use 17ga spokes on the right
side rear. First and foremost is that windup during building can
limit the amount of tension that you can apply to right side spokes,
and this in turn will require you to use less tension on the left.
(Another r.b.t contributor reported favorable results from applying
molybdenum disulfide lube to the spokes' threads to reduce windup.)
Secondly, the thinner and stretchier 17ga spokes under high drive side
tension will make your wheel more flexible under side loads,
increasing the risk of bending your rim out of true or even collapsing
your wheel.

1.8mm spokes have 44% more cross-sectional area than 1.5mm spokes.
2.0mm spokes have 78% more cross-sectional area. Since your drive
side spokes are tensioned 3x higher than your left side spokes, it
doesn't make sense for them to be the same gauge-- especially when
that gauge is optimized for the lower-tension side.

Chalo
 
On Aug 8, 7:34 am, Art Harris <[email protected]> wrote:
> "Spike" wrote:
> > I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
> > wheels. What are the reasons for and advisability of using heavier,
> > e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
> > Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
> > use all 14/17/14's.


snip
> What do you expect to gain by using 14/17/14 spokes?
>
> Art Harris


The 14/17/14 gauge spokes are what I have at hand and by using only
14/17/14 spokes one obtains not only greater aesthetics but also the
elegance of simplicity. If 14/17/14 spokes have sufficient physicals
and workability for front wheel use, then one might think that they
would also be suitable for rear wheels. Although their tensile
strength is less than 14/15/14 spokes, isn't it still mush greater
than required? Maybe I should have asked what does one expect to gain
by using 14/15/14 spokes on the rear drive side -- windup aside --
that isn't provided by using 14/17/14 spokes?
 
A

Art Harris

Guest
"Spike" wrote:
>
> If 14/17/14 spokes have sufficient physicals
> and workability for front wheel use, then one might think that they
> would also be suitable for rear wheels.


Front wheels have equal tension on both sides; rear wheels don't.
Personally, I wouldn't use 14/17/14 on the front either. I don't see
any advantage to it.

> Although their tensile
> strength is less than 14/15/14 spokes, isn't it still mush greater
> than required?


17 ga is pretty thin. While spokes normally break at the elbow or
nipple, a "chain into the spokes" or a twig could cause spoke breakage
at the center of such a thin spoke.

And don't under-estimate the problem of getting adequate tension on
the drive side due to spoke wind-up.

If 14/17/14 is what you have, and you want to try it, go ahead. I
wouldn't.

Art Harris
 
On Aug 8, 7:34 am, Art Harris <[email protected]> wrote:
> "Spike" wrote:
> > I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
> > wheels. What are the reasons for and advisability of using heavier,
> > e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
> > Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
> > use all 14/17/14's.

>
> The right side spokes are under nearly twice the tension of left side
> spokes. Since left side spokes are under less tension, they are more
> likely to go slack under load, causing the wheel to go out of true.
>
> Thinner spokes on the left are more elastic, and are less likely to go
> slack.
>
> What do you expect to gain by using 14/17/14 spokes?
>
> Art Harris

Sheldon Brown is beginning to recommend non-drive side spokes be 0
cross so there is no chance of losing enough tension for the nipples
to come loose.

http://www.sheldonbrown.com/wheelbuild.html#half-radial
 
N

Nate Knutson

Guest
> Secondly, the thinner and stretchier 17ga spokes under high drive side
> tension will make your wheel more flexible under side loads,
> increasing the risk of bending your rim out of true or even collapsing
> your wheel.


Could you elaborate more on this? Not arguing, but I'm failing to grok
how this can be true, or how it can be so different for a 1.5 versus a
1.8 spoke, when all the wires we ride on are pretty darn flexy and
also there have been perfectly ridable wheels with highly elastic
spoke materials, like Spinergy. Is the flexibility of the spoke really
that relevant in terms of supporting side loads, compared to the
bracing angle and the tension?
 
A

A Muzi

Guest
> "Spike" wrote:
>> I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
>> wheels. What are the reasons for and advisability of using heavier,
>> e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
>> Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
>> use all 14/17/14's.


Art Harris wrote:
> The right side spokes are under nearly twice the tension of left side
> spokes. Since left side spokes are under less tension, they are more
> likely to go slack under load, causing the wheel to go out of true.
> Thinner spokes on the left are more elastic, and are less likely to go
> slack.
> What do you expect to gain by using 14/17/14 spokes?


Excellent response, Art.

Riders prefer 14-17 etc because they are 'prettier' (like you can see
that) and 'lighter' (both grams!!) and 'better' (everyday race bikes are
merely built with 14-16) so despite cost, hassle and breakage, demand
remains strong.

Look at a wheelbuilder's wheels. 14-16-14.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
 
C

* * Chas

Guest
"Art Harris" <[email protected]> wrote in message
news:[email protected]
> "Spike" wrote:
> >
> > If 14/17/14 spokes have sufficient physicals
> > and workability for front wheel use, then one might think that they
> > would also be suitable for rear wheels.

>
> Front wheels have equal tension on both sides; rear wheels don't.
> Personally, I wouldn't use 14/17/14 on the front either. I don't see
> any advantage to it.
>
> > Although their tensile
> > strength is less than 14/15/14 spokes, isn't it still mush greater
> > than required?

>
> 17 ga is pretty thin. While spokes normally break at the elbow or
> nipple, a "chain into the spokes" or a twig could cause spoke breakage
> at the center of such a thin spoke.
>
> And don't under-estimate the problem of getting adequate tension on
> the drive side due to spoke wind-up.
>
> If 14/17/14 is what you have, and you want to try it, go ahead. I
> wouldn't.
>
> Art Harris
>


I'm a heavy rider ~230 Lbs. I've been using straight 14 gage (2mm) spokes
on most of my rear wheels for years without any problems.

About a month ago I was riding one of my retro bikes with a rear wheel I
picked up used. It had either 15-17-15 or straight 15 gage spokes. I'd
been using it for a while as a stationary bike with out any problems and
decided to take it out for a little spin one evening.

I was chasing a guy on a carbon bike up a short hill and shifted into my
largest rear sprocket, a 26T. About 5 pedal stokes later I heard that
sickening crunch and came to a stop when my rear derailleur got sucked
into the spokes. It trashed the derailleur and rear dropout.

Everything was properly adjusted with adequate clearance between the
derailleur cage and the spokes.

I think that the light gage spokes allowed enough lateral flexing from
honking up the hill that the spokes hit the derailleur.

I've since checked all of my bikes and put spacers behind the freewheels
and cassettes where there was any chance of a collision.

I've ridden 14-15-14, 15-17-15, or straight 15 gage spokes on my front
wheels and never had any problems.

If the OP weighs over 150 Lbs. he should seriously consider the
suggestions against light spokes on the rear. If he can tell the
difference between 14-15-14 spokes and 14-17-14 spokes from 5 feet maybe
he's spending too much time at the coffee shop. ;-)

Chas.
 
On Aug 8, 10:58 am, Art Harris <[email protected]> wrote:
> "Spike" wrote:
>
> > If 14/17/14 spokes have sufficient physicals
> > and workability for front wheel use, then one might think that they
> > would also be suitable for rear wheels.

>
> Front wheels have equal tension on both sides; rear wheels don't.
> Personally, I wouldn't use 14/17/14 on the front either. I don't see
> any advantage to it.
>
> > Although their tensile
> > strength is less than 14/15/14 spokes, isn't it still mush greater
> > than required?

>
> 17 ga is pretty thin. While spokes normally break at the elbow or
> nipple, a "chain into the spokes" or a twig could cause spoke breakage
> at the center of such a thin spoke.
>
> And don't under-estimate the problem of getting adequate tension on
> the drive side due to spoke wind-up.
>
> If 14/17/14 is what you have, and you want to try it, go ahead. I
> wouldn't.
>
> Art Harris



Thank you for your responses; I value your considered opinions.

Spike
 
R

Ron Ruff

Guest
On Aug 8, 3:21 am, [email protected] wrote:
> Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
> use all 14/17/14's.


No problem... do it. The only good reason to use heavier spokes on the
drive side is to make the build easier. Care must be taken to prevent
excess windup of 2.0/1.5mm spokes on the DS.

Most of the lateral stiffness comes from the bracing angle and area of
the NDS spokes. Since the spokes fail from fatigue (usually at the J)
the strength of the ends is most important, and the smaller center
section should actually make the spokes last longer, since this will
reduce the cyclic stress.
 
P

Paul Kopit

Guest
On Wed, 08 Aug 2007 02:21:31 -0700, [email protected] wrote:

>I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
>wheels. What are the reasons for and advisability of using heavier,
>e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
>Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
>use all 14/17/14's.


Spokes that are that thin will twist when you try to put high enough
tension on them. I find that problem even with DT revolution 2/1.5/2,
especially on the drive side. I can build with 1.8/1.6/1.8.
 
C

Chris Nelson

Guest
On Aug 8, 5:21 am, [email protected] wrote:
> I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
> wheels. What are the reasons for and advisability of using heavier,
> e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
> Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
> use all 14/17/14's.
>
> Any and all comments will be appreciated -- except from that one
> disruptive and often in error, orifice of RBT, oracle of RBT
> wannabe, 'even if they don't know, i know their spokes are ground and
> polished, guy.
>
> --
>
> Spike


Try using a hub such as DTSwiss where the left side flange is closer
to center than normal. This will cut down on wheel asymmetry and the
resulting tension disparity mentioned by others.

Chris
 
On Aug 8, 7:05 pm, Paul Kopit <[email protected]> wrote:
> On Wed, 08 Aug 2007 02:21:31 -0700, [email protected] wrote:
> >I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
> >wheels. What are the reasons for and advisability of using heavier,
> >e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
> >Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
> >use all 14/17/14's.

>
> Spokes that are that thin will twist when you try to put high enough
> tension on them. I find that problem even with DT revolution 2/1.5/2,
> especially on the drive side. I can build with 1.8/1.6/1.8.


The 14/17/14 gauge spokes that I was considering using exclusively are
the same DT revolution 2.0/1.5/2.0 mm spokes that you apparently have
used and experienced some DS windup with. (Probably it would have been
better if I had designated them as 2.0/1.5/2.0 mm spokes to begin
with.) I'm not trying to knock out, on a commercial basis, a pair of
very good and well built wheels in a couple of hours. I have the time
to deal with the windup and to enjoy the whole building process.

--

Spike
 
C

Chalo

Guest
Nate Knutson wrote:
> > Secondly, the thinner and stretchier 17ga spokes under high drive side
> > tension will make your wheel more flexible under side loads,
> > increasing the risk of bending your rim out of true or even collapsing
> > your wheel.

>
> Could you elaborate more on this? Not arguing, but I'm failing to grok
> how this can be true, or how it can be so different for a 1.5 versus a
> 1.8 spoke, when all the wires we ride on are pretty darn flexy and
> also there have been perfectly ridable wheels with highly elastic
> spoke materials, like Spinergy. Is the flexibility of the spoke really
> that relevant in terms of supporting side loads, compared to the
> bracing angle and the tension?


Spokes are loaded so purely in tension that their individual rigidity
to bending loads doesn't enter into wheel rigidity in any measurable
way. A wheel flexes because of bending loads on the rim extrusion and
changes in the lengths of spokes. Spokes have 56 threads per inch, so
a quarter turn on a spoke nipple takes up the length of that spoke by
a little over four thousandths of an inch. Yet the effect of a
quarter turn of one single spoke nipple is easy to see in the truing
stand. Make it a half dozen spokes on each side of the wheel, with
the ones one one side getting shorter and the other getting longer,
and you see how this can have an impact on the deflection of the
wheel. In fact, the interdependency of spoke tensions within a wire
wheel means that most of the spokes are involved and tensions will go
both up and down on the same side of the wheel.

Thin spokes are more elastic than thick spokes, meaning that their
length changes more than that of thicker for a given change in load.
Keep in mind that although a side load in either direction changes the
length of the spokes on both sides, the short center-to-flange
dimension on the drive side gives the hub a lot of leverage with which
to effect changes in spoke tension and therefore spoke length. '

Chalo
 
J

jim beam

Guest
Chris Nelson wrote:
> On Aug 8, 5:21 am, [email protected] wrote:
>> I want to build a set of box rimmed, 32 hole, cross 3, 10 speed
>> wheels. What are the reasons for and advisability of using heavier,
>> e.g. 14/15/14 gauge, spokes on the rear drive side, as is often done?
>> Do I need to do this? I'm not a two kilowatt sprinter; I'd like to
>> use all 14/17/14's.
>>
>> Any and all comments will be appreciated -- except from that one
>> disruptive and often in error, orifice of RBT, oracle of RBT
>> wannabe, 'even if they don't know, i know their spokes are ground and
>> polished, guy.
>>
>> --
>>
>> Spike

>
> Try using a hub such as DTSwiss where the left side flange is closer
> to center than normal. This will cut down on wheel asymmetry and the
> resulting tension disparity mentioned by others.
>
> Chris
>


/don't/ do that. closer flanges reduces the bracing angle and therefore
reduces lateral stiffness. combine that with skinny spokes and you'll
likely have a real shimmy issue with that wheel.