half radial lacing on XTR rear hub

[Grey]

Hi,

I am planning to build up a rear wheel for cyclocross using a 28 spoke
xtr hub and open pro rim. I weigh 175 lbs. I was going to use half
radial lacing, since Sheldon Brown's theory on why this is smart makes
sense to me (http://sheldonbrown.com/wheelbuild.html#half-radial). Then
I remembered Shimano's warranty which is voided by radial lacing. Now I
am not sure which way to go. Will they not honor the warranty even for
completely unrelated problems, like the freehub mechanism breaking,
when a hub was built with half radial lacing? Anyone have experience
with that?

I would think that radially laced left spokes are under less tension
than 2 or 3 cross right side spokes on a dished wheel, so Shimano's
concern about hub flange breakage with radial lacing should not be an
issue with half radial. But would they use that as a reason to void the
warranty anyway?

Thanks,

Grey

 

[jim beam]

Grey wrote:
> Hi,
>
> I am planning to build up a rear wheel for cyclocross using a 28 spoke
> xtr hub and open pro rim. I weigh 175 lbs. I was going to use half
> radial lacing, since Sheldon Brown's theory on why this is smart makes
> sense to me (http://sheldonbrown.com/wheelbuild.html#half-radial). Then
> I remembered Shimano's warranty which is voided by radial lacing. Now I
> am not sure which way to go. Will they not honor the warranty even for
> completely unrelated problems, like the freehub mechanism breaking,
> when a hub was built with half radial lacing? Anyone have experience
> with that?
>
> I would think that radially laced left spokes are under less tension
> than 2 or 3 cross right side spokes on a dished wheel, so Shimano's
> concern about hub flange breakage with radial lacing should not be an
> issue with half radial. But would they use that as a reason to void the
> warranty anyway?
>
> Thanks,
>
> Grey
>
the tension ratio for xtr is approx. 65% left to right, therefore , half
spoking on the left is inadvisable - spoke tension on that side will
exceed tension on the drive side. that coupled with a radial pattern
will leave you wide open to hub flange problems. if you want to weight
weeny, just use revo spokes on that side.

 

[Sheldon Brown]

"Grey" wrote:

>> I am planning to build up a rear wheel for cyclocross using a 28 spoke
>> xtr hub and open pro rim. I weigh 175 lbs. I was going to use half
>> radial lacing, since Sheldon Brown's theory on why this is smart makes
>> sense to me (http://sheldonbrown.com/wheelbuild.html#half-radial). Then
>> I remembered Shimano's warranty which is voided by radial lacing. Now I
>> am not sure which way to go. Will they not honor the warranty even for
>> completely unrelated problems, like the freehub mechanism breaking,
>> when a hub was built with half radial lacing?

I can't believe they would do that.

>> I would think that radially laced left spokes are under less tension
>> than 2 or 3 cross right side spokes on a dished wheel, so Shimano's
>> concern about hub flange breakage with radial lacing should not be an
>> issue with half radial. But would they use that as a reason to void the
>> warranty anyway?
>>
jim beam wrote:
>>
> the tension ratio for xtr is approx. 65% left to right, therefore , half
> spoking on the left is inadvisable - spoke tension on that side will
> exceed tension on the drive side. that coupled with a radial pattern
> will leave you wide open to hub flange problems. if you want to weight
> weeny, just use revo spokes on that side.

I think Jim misunderstood what was being proposed.

"Half-radial" means that half of the spokes are radial, half are
sem-tangent. In the mode I recommend, it is the spokes that run from
the left flange that are radial, the right side is semi-tangent. The
static spoke tension has nothing to do with the pattern, radial or
semi-tangent are the same.

My guess is that Jim focussedd on the "half" and concluded that you were
proposing to only use 7 spokes ("half" as many) on the left side. That
would, indeed, be a Bad Idea in my opinion.

Sheldon "Half And Half" Brown
+---------------------------------------------+
| I have suffered from being misunderstood |
| but I would have suffered a hell of a lot |
| more if I had been understood. |
| --Clarence Darrow |
+---------------------------------------------+
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

 

[jim beam]

Sheldon Brown wrote:
> "Grey" wrote:
>
>>> I am planning to build up a rear wheel for cyclocross using a 28 spoke
>>> xtr hub and open pro rim. I weigh 175 lbs. I was going to use half
>>> radial lacing, since Sheldon Brown's theory on why this is smart makes
>>> sense to me (http://sheldonbrown.com/wheelbuild.html#half-radial). Then
>>> I remembered Shimano's warranty which is voided by radial lacing. Now I
>>> am not sure which way to go. Will they not honor the warranty even for
>>> completely unrelated problems, like the freehub mechanism breaking,
>>> when a hub was built with half radial lacing?
>
>
> I can't believe they would do that.
>
>>> I would think that radially laced left spokes are under less tension
>>> than 2 or 3 cross right side spokes on a dished wheel, so Shimano's
>>> concern about hub flange breakage with radial lacing should not be an
>>> issue with half radial. But would they use that as a reason to void the
>>> warranty anyway?
>>>
> jim beam wrote:
>
>>>
>> the tension ratio for xtr is approx. 65% left to right, therefore ,
>> half spoking on the left is inadvisable - spoke tension on that side
>> will exceed tension on the drive side. that coupled with a radial
>> pattern will leave you wide open to hub flange problems. if you want
>> to weight weeny, just use revo spokes on that side.
>
>
> I think Jim misunderstood what was being proposed.
>
> "Half-radial" means that half of the spokes are radial, half are
> sem-tangent. In the mode I recommend, it is the spokes that run from
> the left flange that are radial, the right side is semi-tangent. The
> static spoke tension has nothing to do with the pattern, radial or
> semi-tangent are the same.
>
> My guess is that Jim focussedd on the "half" and concluded that you were
> proposing to only use 7 spokes ("half" as many) on the left side.

you guessed my guess correctly!

i guess i should qualify my statements: if a wheel has half the number
of spokes on one side, individual spoke tension on that side must double
to retain equilibrium with the other.

example: if a campy wheel has 50% tension ratio, which it pretty much
does, you can have half the number of spokes on the left side and all
spoke tensions will be about the same. this from where campy's "g3"
spoking is derived.

if however your tension ratio is 65%, you'll need 9 spokes on the left
side to get even tension both sides. and 9 is not something you can
easily spoke on a 28-hole rim.

> That
> would, indeed, be a Bad Idea in my opinion.
>
> Sheldon "Half And Half" Brown
> +---------------------------------------------+
> | I have suffered from being misunderstood |
> | but I would have suffered a hell of a lot |
> | more if I had been understood. |
> | --Clarence Darrow |
> +---------------------------------------------+
> 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
>

 

[Martyn Aldis]

In message <[email protected]>, jim beam
<[email protected]> writes
>Grey wrote:
>> Hi,
>> I am planning to build up a rear wheel for cyclocross using a 28 spoke
>> xtr hub and open pro rim. I weigh 175 lbs. I was going to use half
>> radial lacing, since Sheldon Brown's theory on why this is smart makes
>> sense to me (http://sheldonbrown.com/wheelbuild.html#half-radial). Then
>> I remembered Shimano's warranty which is voided by radial lacing. Now I
>> am not sure which way to go. Will they not honor the warranty even for
>> completely unrelated problems, like the freehub mechanism breaking,
>> when a hub was built with half radial lacing? Anyone have experience
>> with that?
>> I would think that radially laced left spokes are under less tension
>> than 2 or 3 cross right side spokes on a dished wheel, so Shimano's
>> concern about hub flange breakage with radial lacing should not be an
>> issue with half radial. But would they use that as a reason to void the
>> warranty anyway?
>> Thanks,
>> Grey
>>
>the tension ratio for xtr is approx. 65% left to right, therefore , half
>spoking on the left is inadvisable - spoke tension on that side will exceed
>tension on the drive side. that coupled with a radial pattern will leave you
>wide open to hub flange problems. if you want to weight weeny, just use
>revo spokes on that side.

Maybe a crossed wire here -

Grey means 14 spokes a side, radial left side, semi-tangential right
side
but Jim's "coupled with" suggests he is thinking of half the number of
spokes on the left.

I don't see that pre-tensioning differences are significant between
a radial and a semi-tangential spoke for a 622mm wheel with any normal
size of hub. The semi-tangentials only arrive a few degrees off the
radius.

Take a hub with a hole circle radius of 32mm
tan a = 32/590 so a is about 3 degrees.

To give the same pull in the radial direction the tension will be
multiplied by:

1 - Cosine of 3 degrees
1 - 0.998
= 1.002

Is this right?
--

Martyn Aldis, e-mail [email protected]
==============================================================================

 

[amakyonin]

Why don't you just lace it 2-cross on both sides. It looks almost like
radial and you stand a better chance of making a successful field
repair if a spoke breaks.

 

[jim beam]

Martyn Aldis wrote:
> In message <[email protected]>, jim beam
> <[email protected]> writes
>
>>Grey wrote:
>>
>>>Hi,
>>> I am planning to build up a rear wheel for cyclocross using a 28 spoke
>>>xtr hub and open pro rim. I weigh 175 lbs. I was going to use half
>>>radial lacing, since Sheldon Brown's theory on why this is smart makes
>>>sense to me (http://sheldonbrown.com/wheelbuild.html#half-radial). Then
>>>I remembered Shimano's warranty which is voided by radial lacing. Now I
>>>am not sure which way to go. Will they not honor the warranty even for
>>>completely unrelated problems, like the freehub mechanism breaking,
>>>when a hub was built with half radial lacing? Anyone have experience
>>>with that?
>>> I would think that radially laced left spokes are under less tension
>>>than 2 or 3 cross right side spokes on a dished wheel, so Shimano's
>>>concern about hub flange breakage with radial lacing should not be an
>>>issue with half radial. But would they use that as a reason to void the
>>>warranty anyway?
>>> Thanks,
>>> Grey
>>>
>>
>>the tension ratio for xtr is approx. 65% left to right, therefore , half
>>spoking on the left is inadvisable - spoke tension on that side will exceed
>>tension on the drive side. that coupled with a radial pattern will leave you
>>wide open to hub flange problems. if you want to weight weeny, just use
>>revo spokes on that side.
>
>
> Maybe a crossed wire here -
>
> Grey means 14 spokes a side, radial left side, semi-tangential right
> side
> but Jim's "coupled with" suggests he is thinking of half the number of
> spokes on the left.
>
> I don't see that pre-tensioning differences are significant between
> a radial and a semi-tangential spoke for a 622mm wheel with any normal
> size of hub. The semi-tangentials only arrive a few degrees off the
> radius.
>
> Take a hub with a hole circle radius of 32mm
> tan a = 32/590 so a is about 3 degrees.
>
> To give the same pull in the radial direction the tension will be
> multiplied by:
>
> 1 - Cosine of 3 degrees
> 1 - 0.998
> = 1.002
>
> Is this right?

good enough. i was thinking half the number of spokes.

 

[[email protected]]

Grey wrote:
> I am planning to build up a rear wheel for cyclocross using a 28 spoke
> xtr hub and open pro rim. I weigh 175 lbs. I was going to use half
> radial lacing, since Sheldon Brown's theory on why this is smart makes
> sense to me (http://sheldonbrown.com/wheelbuild.html#half-radial). Then
> I remembered Shimano's warranty which is voided by radial lacing.

My 2c's : why not do something like a 3-cross on the drive side and a
2-cross on the other (NDS) side, or maybe rather 2x / 1x for 28 spokes?

It takes the advantages of the less dimishing tension on the NDS, AND
does not put as much stress on the fange as the radial one - or at
least does not void warranty.


It can also be combined with different spoke gauges, as said amakyonin
- DTRevo's on the NDS would be weel adapted, as the lesser tension
makes the winding problem less problematic while building. In this
case, it might be advisable to take the NDS spokes a tad shorter (1mm?)
if the spoke calculator does not take differential spoke elongation
into account.

 

[daveornee]

Grey wrote:
> I am planning to build up a rear wheel for cyclocross using a 28 spoke
> xtr hub and open pro rim. I weigh 175 lbs. I was going to use half
> radial lacing, since Sheldon Brown's theory on why this is smart makes
> sense to me (http://sheldonbrown.com/wheelbuild.html#half-radial). Then
> I remembered Shimano's warranty which is voided by radial lacing.

My 2c's : why not do something like a 3-cross on the drive side and a
2-cross on the other (NDS) side, or maybe rather 2x / 1x for 28 spokes?

It takes the advantages of the less dimishing tension on the NDS, AND
does not put as much stress on the fange as the radial one - or at
least does not void warranty.


It can also be combined with different spoke gauges, as said amakyonin
- DTRevo's on the NDS would be weel adapted, as the lesser tension
makes the winding problem less problematic while building. In this
case, it might be advisable to take the NDS spokes a tad shorter (1mm?)
if the spoke calculator does not take differential spoke elongation
into account.

I suggest that respondents read Sheldon's 1/2 radial article.
I am not a proponent of this method, but when used, it does result in closer tension balance left to right due to the NDS spokes all exiting from the inside (right) side of the left hub flange.
If you use 1X or 2X on the NDS, while using 3X on drive side, the result is more un-even tesnion left to right.
I prefer semi-tangential spoking on both flnages. I go along with the idea of using thinner guage (DT Revolution, Sapim Laser, etc.) on left and especially when used with OCR type rim, it helps keep the left spokes from going slack during dynamic loading.