Radial on DS!?

[Luke Forward]

Radial on DS works? It seems against the drive-torgue theory.

My understading is that to transmit drive torgue, the rear hub DS must
at least be X2 laced,
the NDS is free to be laced radial to X4.

Powertap hub is unigue having its DS on the left. The manufacturer
says the left(DS) must be laced X3. This makes sence to me.

Shockingly, Robert Torre claimed "A properly built half radial rear
wheel will be radially laced on the drive side. It would also be best
to lace the drive side so the spoke heads are on the inside of the
flange." http://www.geocities.com/spokeanwheel/lacingsr.htm#hr

Shimano wheelsets have a unique radial-DS design which seems to be
discontined from the change of Dura Ace 7850. see
http://www.cyclingnews.com/photos.p...ws/08-20/Shimano_Dura-Ace_WH-7850-SL_rear_hub

So does it mean that Shimano think Radial-DS fails?

Dear builders have you ever build a Radial-DS that works?

 

[dabac]

Radial on DS works? It seems against the drive-torgue theory.

My understading is that to transmit drive torgue, the rear hub DS must
at least be X2 laced,
the NDS is free to be laced radial to X4.

Powertap hub is unigue having its DS on the left. The manufacturer
says the left(DS) must be laced X3. This makes sence to me.

Shockingly, Robert Torre claimed "A properly built half radial rear
wheel will be radially laced on the drive side. It would also be best
to lace the drive side so the spoke heads are on the inside of the
flange." http://www.geocities.com/spokeanwheel/lacingsr.htm#hr

Shimano wheelsets have a unique radial-DS design which seems to be
discontined from the change of Dura Ace 7850. see
http://www.cyclingnews.com/photos.p...ws/08-20/Shimano_Dura-Ace_WH-7850-SL_rear_hub

So does it mean that Shimano think Radial-DS fails?

Dear builders have you ever build a Radial-DS that works?

The short answer is that if properly built, for most applications the margins are big enough to allow for functional wheels to be built in a number of configurations.
That a RW needs some tangential spokes is uniformly accepted by all, although I've seen high spoke count "cruiser" bikes built with full-radial rear wheels.
Some will claim that the RW hub will twist so much under pedalling force that the DS flange MUST be tangentially laced.
Other scorns the idea of a puny human being able to substantially deform by torsion a chunky aluminum cylinder and will happily put the tangentially laced spokes anywhere they damn well wants. Heads-in, radial lacing of the DS then will give a slight improvement in spoke angle, equivalent to having the flange 1/2 of the flange thickness further out as compared to a tangentially laced flange. So if you're more concerned with spoke angle than with hub twisting then that's the choice for you.

 

[Michael Johnson]

Luke Forward wrote:
> Radial on DS works? It seems against the drive-torgue theory.
>
> My understading is that to transmit drive torgue, the rear hub DS must
> at least be X2 laced,
> the NDS is free to be laced radial to X4.
>
> Powertap hub is unigue having its DS on the left. The manufacturer
> says the left(DS) must be laced X3. This makes sence to me.
>
> Shockingly, Robert Torre claimed "A properly built half radial rear
> wheel will be radially laced on the drive side. It would also be best
> to lace the drive side so the spoke heads are on the inside of the
> flange." http://www.geocities.com/spokeanwheel/lacingsr.htm#hr
>
> Shimano wheelsets have a unique radial-DS design which seems to be
> discontined from the change of Dura Ace 7850. see
> http://www.cyclingnews.com/photos.p...ws/08-20/Shimano_Dura-Ace_WH-7850-SL_rear_hub
>
> So does it mean that Shimano think Radial-DS fails?
>
> Dear builders have you ever build a Radial-DS that works?

I have a set of WH-7801-SL wheels, which are Radial-DS, and they've been
absolutely bullet-proof. Robert also points out that the drive torque
will be transmitted through the hub shell with negligible twisting, so
there's no reason not to put the drive spokes on the non-drive side. The
reason for building a Radial-DS wheel is to try to balance the spoke
tensions. However, Robert also states that a 2x/3x with 3x on the drive
side is better than a Radial-DS wheel. He gives some convincing reasons
for his point of view.

I suspect that Shimano's motivation in building a 2x/2x wheel was
probably mainly cost reduction. However, they might also have been
trying to increase wheel life by spreading the drive loads across twice
as many spokes and, consequently, more evenly around the rim.

Mike Johnson

 

[Ron Ruff]

On Jan 11, 2:38 am, Luke Forward <[email protected]> wrote:
> Radial on DS works? It seems against the drive-torgue theory.

If the hub shell is beefy enough, it does a fine job of transmitting
torque to the NDS.

> Powertap hub is unigue having its DS on the left. The manufacturer
> says the left(DS) must be laced X3. This makes sence to me.

The DS is the side that the cogs are on. The PT hub body is quite
beefy and large diameter... you can cross spokes on either side and it
will work fine. The manufacturer seems to be confused about this
however.

> Shockingly, Robert Torre claimed "A properly built half radial rear
> wheel will be radially laced on the drive side. It would also be best
> to lace the drive side so the spoke heads are on the inside of the
> flange."  http://www.geocities.com/spokeanwheel/lacingsr.htm#hr

Try that and guess how long the flange will last. Also having spokes
with heads in on the DS will increase the bracing angle and improve
the tension balance, but the flange is *already* as far over as
possible to keep the derailleur from hitting the spokes. If you have
extra clearance then maybe you could get away with it. Another issue
is that using only the NDS spokes (which have low tension to start
with) for torque transmission increases the chance that they will go
slack from combined torque and radial/lateral loads. Robert Torre has
a big website, but you should not believe most of what is on it...

> So does it mean that Shimano think Radial-DS fails?

Mavic has been doing this for many years, mostly because their fat
aluminum spokes would require too much dish if they were crossed on
the DS. If the wheel is properly designed it works fine. I don't think
it is a good idea on hubs that aren't designed for it though.

 

[Luke Forward]

On Jan 12, 12:13 am, Ron Ruff <[email protected]> wrote:
> On Jan 11, 2:38 am, Luke Forward <[email protected]> wrote:
> > Powertap hub is unigue having its DS on the left. The manufacturer
> > says the left(DS) must be laced X3. This makes sence to me.
>
> The DS is the side that the cogs are on. The PT hub body is quite
> beefy and large diameter... you can cross spokes on either side and it
> will work fine. The manufacturer seems to be confused about this
> however.

I've read the manual of Powertap hub in which it has a cutaway
picture, the hub structure does have a driveside on its left(no cogs).
Ligero built it leftside X3 rightside X1. see
http://www.flickr.com/photos/ligerowheels/577544451/in/set-72157600523553677/

 

[David L. Johnson]

Michael Johnson wrote:

>> Powertap hub is unigue having its DS on the left. The manufacturer
>> says the left(DS) must be laced X3. This makes sence to me.

Well, it doesn't to me. How can the drive side be on the left? The
chain is where?
>>
>> Shockingly, Robert Torre claimed "A properly built half radial rear
>> wheel will be radially laced on the drive side. It would also be best
>> to lace the drive side so the spoke heads are on the inside of the
>> flange." http://www.geocities.com/spokeanwheel/lacingsr.htm#hr

That would be rather shocking. Not only does it require a hub with a
stronger (and heavier) shell, but putting heads in moves the spokes out
closer to the chain. Infinitesimally that will improve the bracing
angle, but at the cost of, well, the spokes being closer to the chain.

>> So does it mean that Shimano think Radial-DS fails?

What makes you think they think it "fails"? It's all just marketing,
anyway. They need to change the design every season, or no one will buy
their wheels just because their old ones are out of fashion. Can't have
that.

> I have a set of WH-7801-SL wheels, which are Radial-DS, and they've been
> absolutely bullet-proof. Robert also points out that the drive torque
> will be transmitted through the hub shell with negligible twisting,

It better be negligible. But a standard hub shell is not able to
prevent such twisting.

> there's no reason not to put the drive spokes on the non-drive side. The
> reason for building a Radial-DS wheel is to try to balance the spoke
> tensions.

You might try to balance the spoke tension that way, but you would fail.

> I suspect that Shimano's motivation in building a 2x/2x wheel was
> probably mainly cost reduction. However, they might also have been
> trying to increase wheel life by spreading the drive loads across twice
> as many spokes and, consequently, more evenly around the rim.

Huh?

--

David L. Johnson

As far as the laws of mathematics refer to reality, they are not
certain, and as far as they are certain, they do not refer to reality.
-- Albert Einstein

 

[Ben C]

On 2008-01-11, David L. Johnson <[email protected]> wrote:
> Michael Johnson wrote:
>
>>> Powertap hub is unigue having its DS on the left. The manufacturer
>>> says the left(DS) must be laced X3. This makes sence to me.
>
> Well, it doesn't to me. How can the drive side be on the left? The
> chain is where?

I suppose the chain could be on the right, but the pawls that actually
engage the hub could be over on the left.

 

[[email protected]]

Look Backward writes:

> Radial on DS works? It seems against the drive-torgue theory.

> My understading is that to transmit drive torgue, the rear hub DS
> must at least be X2 laced, the NDS is free to be laced radial to X4.

> Powertap hub is unigue having its DS on the left. The manufacturer
> says the left(DS) must be laced X3. This makes sence to me.

> Shockingly, Robert Torre claimed "A properly built half radial rear
> wheel will be radially laced on the drive side. It would also be
> best to lace the drive side so the spoke heads are on the inside of
> the flange."

http://www.geocities.com/spokeanwheel/lacingsr.htm#hr

> Shimano wheelsets have a unique radial-DS design which seems to be
> discontined from the change of Dura Ace 7850. see

http://www.cyclingnews.com/photos.p...ws/08-20/Shimano_Dura-Ace_WH-7850-SL_rear_hub

> So does it mean that Shimano think Radial-DS fails?

> Dear builders have you ever build a Radial-DS that works?

Just because someone does it and it appears to work doesn't mean it is
good or even better than conventional design. Just to prove that, one
of the guys at the bicycle shop spokes a standard low flange
Campagnolo hub radially on both sides and allowed people to ride it so
they could discover that torque wind-up is imperceptible. In the long
run this will tear the flange apart as has been show even by 3x
spoking when the hub was re-spoked with opposite spoke orientation.

Jobst Brandt

 

[Zog The Undeniable]

Luke Forward wrote:
> Radial on DS works? It seems against the drive-torgue theory.
>
> My understading is that to transmit drive torgue, the rear hub DS must
> at least be X2 laced,
> the NDS is free to be laced radial to X4.
>
> Powertap hub is unigue having its DS on the left. The manufacturer
> says the left(DS) must be laced X3. This makes sence to me.
>
> Shockingly, Robert Torre claimed "A properly built half radial rear
> wheel will be radially laced on the drive side. It would also be best
> to lace the drive side so the spoke heads are on the inside of the
> flange." http://www.geocities.com/spokeanwheel/lacingsr.htm#hr
>
> Shimano wheelsets have a unique radial-DS design which seems to be
> discontined from the change of Dura Ace 7850. see
> http://www.cyclingnews.com/photos.p...ws/08-20/Shimano_Dura-Ace_WH-7850-SL_rear_hub
>
> So does it mean that Shimano think Radial-DS fails?
>
> Dear builders have you ever build a Radial-DS that works?

It's been done for years. You just have to ensure the hub shell can
take it.

BMX bikes with small wheels and 48 spokes, and low-riders with 144
spokes, often have completely radial rear wheels, spoke wind-up being
less of a problem in these cases.

 

[Ron Ruff]

On Jan 11, 9:42 am, Luke Forward <[email protected]> wrote:
> I've read the manual of Powertap hub in which it has a cutaway
> picture, the hub structure does have a driveside on its left(no cogs).

I know how the hub works... but there is no practical reason to
designate the left side as the drive side.

 

[[email protected]]

Ron Ruff writes:

>> I've read the manual of Powertap hub in which it has a cutaway
>> picture, the hub structure does have a drive side on its left(no
>> cogs).

> I know how the hub works... but there is no practical reason to
> designate the left side as the drive side.

It is the side on which drive torque enters the hub. With most hubs
the ratchet escapement is at the sprockets and therefore on the right
side. If the mechanism is on the left side, and I can't imagine why
one would do that, then the left side is the driven (drive) side.

Just the same, I find plain English of "left" and "right" sides of a
rear wheel, rather than with bicycle jargon of "DS" and "NDS", terms
that can lead to confusion.

Jobst Brandt

 

[Tom Sherman]

[email protected] aka Jobst Brandt wrote:
> ...
> Just the same, I find plain English of "left" and "right" sides of a
> rear wheel, rather than with bicycle jargon of "DS" and "NDS", terms
> that can lead to confusion.

The portion of the crank-arm-set on my bicycle that holds the chain
wheels is mounted on the non-non-drive-side.

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people." A. Derleth

 

[[email protected]]

Tom Sherman writes:

>> ...
>> Just the same, I find plain English of "left" and "right" sides of a
>> rear wheel, rather than with bicycle jargon of "DS" and "NDS", terms
>> that can lead to confusion.

> The portion of the crank-arm-set on my bicycle that holds the chain
> wheels is mounted on the non-non-drive-side.

Well said! Does that impact your riding before the twelve o'clock hour
on major roadways? Lying down on the job, as you do, you ought to
worry about tanker-trucks and 18-wheelers when riding in the right
hand lane very very much. Ain't jargon great!

Jobst Brandt

 

[Ron Ruff]

On Jan 11, 5:42 pm, [email protected] wrote:
> It is the side on which drive torque enters the hub.  With most hubs
> the ratchet escapement is at the sprockets and therefore on the right
> side.  If the mechanism is on the left side, and I can't imagine why
> one would do that, then the left side is the driven (drive) side.

Powertap has their torque measuring device (probably strain gauges on
a tube) between the freehub and the left side of the hub body... the
right side of the hub body is not rigidly attached to the freehub (it
floats). So by your definition the left side is the drive side. But in
practical terms, the hub body is quite solid and either flange will
transfer torque effectively... ie no risk of failure or error in
torque measurement.

 

[[email protected]]

Ron Ruff writes:

>> It is the side on which drive torque enters the hub.  With most
>> hubs the ratchet escapement is at the sprockets and therefore on
>> the right side.  If the mechanism is on the left side, and I can't
>> imagine why one would do that, then the left side is the driven
>> (drive) side.

> Powertap has their torque measuring device (probably strain gauges
> on a tube) between the freehub and the left side of the hub body...
> the right side of the hub body is not rigidly attached to the
> freehub (it floats). So by your definition the left side is the
> drive side. But in practical terms, the hub body is quite solid and
> either flange will transfer torque effectively... ie no risk of
> failure or error in torque measurement.

From what I can see in pictures the "tube" is made of four slightly
angled beams that are loaded in bending, the rest of the hub tube
having been machined away. It seems that torque may be measured by
bending of these elements.

http://www.wheelbuilder.com/thumbnail.asp?cid=51&offset=0

Jobst Brandt

 

[Ron Ruff]

On Jan 12, 1:57 am, [email protected] wrote:
> From what I can see in pictures the "tube" is made of four slightly
> angled beams that are loaded in bending, the rest of the hub tube
> having been machined away.  It seems that torque may be measured by
> bending of these elements.
>
> http://www.wheelbuilder.com/thumbnail.asp?cid=51&offset=0

That is just the exterior of the hub body. The new ones are made that
way, with a carbon shell underneath that... for fashion. The tube I'm
speaking of is internal, and connects the freehub to the left side of
the hub.