Dimpled frames.

Marty Wallace said:

With dimples being the latest fad in wheels and helmets,
http://www.cyclingnews.com/photos/2004/tour04/tech/?id=zipp/808

are there any dimpled frames out there?

Yeah - I had bad chainsuck once.

"Marty Wallace" <[email hidden]> schreef in bericht
news:[email hidden]...

Quoted message said:

With dimples being the latest fad in wheels and helmets,
http://www.cyclingnews.com/photos/2004/tour04/tech/?id=zipp/808

are there any dimpled frames out there?

Marty

What would be the valve length ?
Is it real or is it Photoshop?

Bert

--
Posted by news://news.nb.nu

Marty Wallace said:

With dimples being the latest fad in wheels and helmets,
are there any dimpled frames out there?

Oh yes.

http://www.hillbrick.com.au/graphics/xlr8r.gif

http://www.hillbrick.com.au/frames/frames_xlr8r.html

http://www.cyclingnews.com/photos/2002/tradeshows02/baus02/DSCN5106.jpg

I quote:

Multishape Damping Effect

XLR8R tubes only can be particularly shaped to obtain a sensible
damping effect of vibration phenomena. The idea is to use a shape
dam on the tube surface in order to damp vibrations in the frame.
This damp effect is obtained by creating three different diameter
punches, on both sides of the top and down tube ends, near the
head tube connection area. The punches are positioned in a zone
where the vibrations coming from the fork enter the frame structure.
Their particular shape enables the vibration dampening in two ways:

1. By creating a physical obstacle to the free movement of the
vibration waves along the tube

2. The emispheric shape of the punches enables the dissipation
of the vibration energy.

Columbus R&D dept. has made severe and repeated tests to define
the dimension and position of the punches and to check the damping
effect. Thanks to this Multishape damping effect, Columbus studies
proved that the vibration phenomena on XLR8R frames come up at
higher average speed than usual.

This is the formula of its success

I'm convinced.

James Thomson

TIC: Golf balls are dimpled to reduce drag. This may be an unexplored
direction in bicycle technology.

Leo Lichtman said:

TIC: Golf balls are dimpled to reduce drag. This may be an unexplored
direction in bicycle technology.

The trick is to get the frame spinning at a few hundred RPM to make
the dimples work - it's REALLY hard to stay on the bike.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $695 ti frame

Leo Lichtman said:

TIC: Golf balls are dimpled to reduce drag. This may be an unexplored
direction in bicycle technology.

Did you not notice Jan Ullrich's time trial helmet from last year's
Tour de France?

http://www.velonews.com/images/details/4570.5568.f.jpg

Very titlist-ey.
--
terry morse Palo Alto, CA http://bike.terrymorse.com/

Mark Hickey said:

Leo Lichtman said:

TIC: Golf balls are dimpled to reduce drag. This may be an unexplored
direction in bicycle technology.

The trick is to get the frame spinning at a few hundred RPM to make
the dimples work - it's REALLY hard to stay on the bike.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $695 ti frame

Dear Mark,

As I understand it, the dimpling effect would actually work
without spinning.

The trick is to present a regularly irregular surface
(sorry, but I can't think of a better phrase) to act as a
trip-wire and produce a thin, even layer of turbulent air
over the ball's surface that reduces separation and drag.

Here's a page with the famous trip-wire demonstration
pictures at the bottom:

http://www.princeton.edu/~asmits/Bicycle_web/blunt.html

Dimples are just the easiest way to reduce drag. They give
increased distance, while the spin is what gives loft,
shank, and slice--and would do so with a smooth ball, too:

http://www.princeton.edu/~asmits/Bicycle_web/sportsballs.html

Carl Fogel

"Bert L.am" <[email hidden]> wrote in message news:[email hidden]...

Quoted message said:

"Marty Wallace" <[email hidden]> schreef in bericht
news:[email hidden]...

Quoted message said:

With dimples being the latest fad in wheels and helmets,
http://www.cyclingnews.com/photos/2004/tour04/tech/?id=zipp/808

are there any dimpled frames out there?

Marty

What would be the valve length ?
Is it real or is it Photoshop?

Bert

--
Posted by news://news.nb.nu

Yes it's real. Very expensive to produce apparently.

Marty

Quoted message said:

Mark Hickey said:

Leo Lichtman said:

TIC: Golf balls are dimpled to reduce drag. This may be an unexplored
direction in bicycle technology.

The trick is to get the frame spinning at a few hundred RPM to make
the dimples work - it's REALLY hard to stay on the bike.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $695 ti frame

Dear Mark,

As I understand it, the dimpling effect would actually work
without spinning.

The trick is to present a regularly irregular surface
(sorry, but I can't think of a better phrase) to act as a
trip-wire and produce a thin, even layer of turbulent air
over the ball's surface that reduces separation and drag.

Here's a page with the famous trip-wire demonstration
pictures at the bottom:

http://www.princeton.edu/~asmits/Bicycle_web/blunt.html

fig 5 is a rather good illustration! thanks carl.

Quoted message said:

Dimples are just the easiest way to reduce drag. They give
increased distance, while the spin is what gives loft,
shank, and slice--and would do so with a smooth ball, too:

http://www.princeton.edu/~asmits/Bicycle_web/sportsballs.html

Carl Fogel

jim beam said:

Quoted message said:

Mark Hickey said:

"Leo Lichtman" <[email hidden]> wrote:

>TIC: Golf balls are dimpled to reduce drag. This may be an unexplored
>direction in bicycle technology.

The trick is to get the frame spinning at a few hundred RPM to make
the dimples work - it's REALLY hard to stay on the bike.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $695 ti frame

Dear Mark,

As I understand it, the dimpling effect would actually work
without spinning.

The trick is to present a regularly irregular surface
(sorry, but I can't think of a better phrase) to act as a
trip-wire and produce a thin, even layer of turbulent air
over the ball's surface that reduces separation and drag.

Here's a page with the famous trip-wire demonstration
pictures at the bottom:

http://www.princeton.edu/~asmits/Bicycle_web/blunt.html

fig 5 is a rather good illustration! thanks carl.

Quoted message said:

Dimples are just the easiest way to reduce drag. They give
increased distance, while the spin is what gives loft,
shank, and slice--and would do so with a smooth ball, too:

http://www.princeton.edu/~asmits/Bicycle_web/sportsballs.html

Carl Fogel

Dear Jim,

Here's an even better copy of the drag pictures, which
eluded me at first:

http://www.efluids.com/efluids/gallery/flow_past_sphere.htm

The text is nice, too, since it explains that the pictures
are of air bubbles in flowing water, not smoke in a wind
tunnel as most people assume.

The odd parallel lines that often puzzle people, the ones
sticking out to the right of the sphere, are just the bar
that holds the sphere in place against the force of the
flowing water--in air, a sphere would have been suspended
from a wire.

Dimples would achieve roughly the same effect as the
circular trip wire.

Carl Fogel

Quoted message said:

jim beam said:

Quoted message said:

On Mon, 13 Dec 2004 18:02:41 -0700, Mark Hickey
<[email hidden]> wrote:

>"Leo Lichtman" <[email hidden]> wrote:
>
>
>
>>TIC: Golf balls are dimpled to reduce drag. This may be an unexplored
>>direction in bicycle technology.
>
>The trick is to get the frame spinning at a few hundred RPM to make
>the dimples work - it's REALLY hard to stay on the bike.
>
>Mark Hickey
>Habanero Cycles
>http://www.habcycles.com
>Home of the $695 ti frame

Dear Mark,

As I understand it, the dimpling effect would actually work
without spinning.

The trick is to present a regularly irregular surface
(sorry, but I can't think of a better phrase) to act as a
trip-wire and produce a thin, even layer of turbulent air
over the ball's surface that reduces separation and drag.

Here's a page with the famous trip-wire demonstration
pictures at the bottom:

http://www.princeton.edu/~asmits/Bicycle_web/blunt.html

fig 5 is a rather good illustration! thanks carl.

Quoted message said:

Dimples are just the easiest way to reduce drag. They give
increased distance, while the spin is what gives loft,
shank, and slice--and would do so with a smooth ball, too:

http://www.princeton.edu/~asmits/Bicycle_web/sportsballs.html

Carl Fogel

Dear Jim,

Here's an even better copy of the drag pictures, which
eluded me at first:

http://www.efluids.com/efluids/gallery/flow_past_sphere.htm

The text is nice, too, since it explains that the pictures
are of air bubbles in flowing water, not smoke in a wind
tunnel as most people assume.

The odd parallel lines that often puzzle people, the ones
sticking out to the right of the sphere, are just the bar
that holds the sphere in place against the force of the
flowing water--in air, a sphere would have been suspended
from a wire.

Dimples would achieve roughly the same effect as the
circular trip wire.

Carl Fogel

ok, here's one to think about; where would twisted spokes stack up
against ordinary elliptical spokes? 😉

Quoted message said:

Did you not notice Jan Ullrich's time trial helmet from last year's
Tour de France?

http://www.velonews.com/images/details/4570.5568.f.jpg

Very titlist-ey.

But those forearms!!! 😉
--
Phil, Squid-in-Training

On Mon, 13 Dec 2004 19:25:51 -0800, jim beam
<[email hidden]> wrote:

[snip]

Quoted message said:

ok, here's one to think about; where would twisted spokes stack up
against ordinary elliptical spokes? 😉

Dear Jim,

Aerodynamically, it's hard to think of anything worse than
the chain-link, snow-flake, twisted-pair spoke-pattern. The
minor reduction in frontal area achieved by wrapping one
spoke around the other is dwarfed by the comparatively giant
irregularity created and the turbulence that it causes.

The twisted section does not mimic the minor dimple on golf
ball--it's more like a golf ball whose owner was handed an
ax instead of a nine-iron.

Anyone who owns a pair of broken spokes can demonstrate the
difference in the sophisticated laboratory of a kitchen
sink. (Those whose spokes are immortal might make do by
cutting a coat-hanger into two pieces in the interest of
science.)

Here's what the precision instrument looks like:

http://home.comcast.net/~carlfogel/download/spoketest.jpg

While the sink is filling with water, twist the spokes
around each other a few times.

Leave the far ends spread in a vee. You'll use the twisted
end as a handle.

Now bend your delicate test probe almost double and dunk it
in the water so that the vee ends stick up out of the water.

Start moving the contraption back and forth sideways through
the water.

At the same speed, the two free ends of the vee will still
be sweeping back and forth across the surface without making
much more than tiny ripples, while a cavitation bubble will
be begin dragging behind the twisted section, just below
where it enters the water.

Cavitation bubbles are not a good thing.

The lay reader must be cautioned not to add dish soap
or--God forbid!--food coloring to the water in hopes of
discovering further secrets. As Victor Frankenstein learned
to his sorrow, there are some doors that man was never meant
to open.

(Besides, you'll already look silly enough, briskly stirring
a sink full of tap water with a pair of bent, busted,
twisted spokes.)

Carl Fogel

Quoted message said:

On Mon, 13 Dec 2004 19:25:51 -0800, jim beam
<[email hidden]> wrote:

[snip]

Quoted message said:

ok, here's one to think about; where would twisted spokes stack up
against ordinary elliptical spokes? 😉

Dear Jim,

Aerodynamically, it's hard to think of anything worse than
the chain-link, snow-flake, twisted-pair spoke-pattern. The
minor reduction in frontal area achieved by wrapping one
spoke around the other is dwarfed by the comparatively giant
irregularity created and the turbulence that it causes.

The twisted section does not mimic the minor dimple on golf
ball--it's more like a golf ball whose owner was handed an
ax instead of a nine-iron.

Anyone who owns a pair of broken spokes can demonstrate the
difference in the sophisticated laboratory of a kitchen
sink. (Those whose spokes are immortal might make do by
cutting a coat-hanger into two pieces in the interest of
science.)

Here's what the precision instrument looks like:

http://home.comcast.net/~carlfogel/download/spoketest.jpg

While the sink is filling with water, twist the spokes
around each other a few times.

Leave the far ends spread in a vee. You'll use the twisted
end as a handle.

Now bend your delicate test probe almost double and dunk it
in the water so that the vee ends stick up out of the water.

Start moving the contraption back and forth sideways through
the water.

At the same speed, the two free ends of the vee will still
be sweeping back and forth across the surface without making
much more than tiny ripples, while a cavitation bubble will
be begin dragging behind the twisted section, just below
where it enters the water.

Cavitation bubbles are not a good thing.

The lay reader must be cautioned not to add dish soap
or--God forbid!--food coloring to the water in hopes of
discovering further secrets. As Victor Frankenstein learned
to his sorrow, there are some doors that man was never meant
to open.

(Besides, you'll already look silly enough, briskly stirring
a sink full of tap water with a pair of bent, busted,
twisted spokes.)

Carl Fogel

sorry carl, i meant this type of spoke

http://www.sapim.be/en/twist.htm

jim beam said:

Quoted message said:

On Mon, 13 Dec 2004 19:25:51 -0800, jim beam
<[email hidden]> wrote:

[snip]

Quoted message said:

ok, here's one to think about; where would twisted spokes stack up
against ordinary elliptical spokes? 😉

Dear Jim,

Aerodynamically, it's hard to think of anything worse than
the chain-link, snow-flake, twisted-pair spoke-pattern. The
minor reduction in frontal area achieved by wrapping one
spoke around the other is dwarfed by the comparatively giant
irregularity created and the turbulence that it causes.

The twisted section does not mimic the minor dimple on golf
ball--it's more like a golf ball whose owner was handed an
ax instead of a nine-iron.

Anyone who owns a pair of broken spokes can demonstrate the
difference in the sophisticated laboratory of a kitchen
sink. (Those whose spokes are immortal might make do by
cutting a coat-hanger into two pieces in the interest of
science.)

Here's what the precision instrument looks like:

http://home.comcast.net/~carlfogel/download/spoketest.jpg

While the sink is filling with water, twist the spokes
around each other a few times.

Leave the far ends spread in a vee. You'll use the twisted
end as a handle.

Now bend your delicate test probe almost double and dunk it
in the water so that the vee ends stick up out of the water.

Start moving the contraption back and forth sideways through
the water.

At the same speed, the two free ends of the vee will still
be sweeping back and forth across the surface without making
much more than tiny ripples, while a cavitation bubble will
be begin dragging behind the twisted section, just below
where it enters the water.

Cavitation bubbles are not a good thing.

The lay reader must be cautioned not to add dish soap
or--God forbid!--food coloring to the water in hopes of
discovering further secrets. As Victor Frankenstein learned
to his sorrow, there are some doors that man was never meant
to open.

(Besides, you'll already look silly enough, briskly stirring
a sink full of tap water with a pair of bent, busted,
twisted spokes.)

Carl Fogel

sorry carl, i meant this type of spoke

http://www.sapim.be/en/twist.htm

Dear Jim,

Hand-twisted or pre-twisted, I suspect that it amounts to
the same thing, which may be why neither is seen in the
Tour, even though lax UCI regulations would allow such
spokes. When the irregularity amounts to a significant
proportion of the object, the aerodynamics suffer.

Carl Fogel

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

jim beam said:

Quoted message said:

On Mon, 13 Dec 2004 18:02:41 -0700, Mark Hickey
<[email hidden]> wrote:

>"Leo Lichtman" <[email hidden]> wrote:
>
>
>>TIC: Golf balls are dimpled to reduce drag. This may be an

unexplored

Quoted message said:

Quoted message said:

Quoted message said:

>>direction in bicycle technology.
>
>The trick is to get the frame spinning at a few hundred RPM to make
>the dimples work - it's REALLY hard to stay on the bike.
>
>Mark Hickey
>Habanero Cycles
>http://www.habcycles.com
>Home of the $695 ti frame

Dear Mark,

As I understand it, the dimpling effect would actually work
without spinning.

The trick is to present a regularly irregular surface
(sorry, but I can't think of a better phrase) to act as a
trip-wire and produce a thin, even layer of turbulent air
over the ball's surface that reduces separation and drag.

Here's a page with the famous trip-wire demonstration
pictures at the bottom:

http://www.princeton.edu/~asmits/Bicycle_web/blunt.html

fig 5 is a rather good illustration! thanks carl.

Quoted message said:

Dimples are just the easiest way to reduce drag. They give
increased distance, while the spin is what gives loft,
shank, and slice--and would do so with a smooth ball, too:

http://www.princeton.edu/~asmits/Bicycle_web/sportsballs.html

Carl Fogel

Dear Jim,

Here's an even better copy of the drag pictures, which
eluded me at first:

http://www.efluids.com/efluids/gallery/flow_past_sphere.htm

The text is nice, too, since it explains that the pictures
are of air bubbles in flowing water, not smoke in a wind
tunnel as most people assume.

The odd parallel lines that often puzzle people, the ones
sticking out to the right of the sphere, are just the bar
that holds the sphere in place against the force of the
flowing water--in air, a sphere would have been suspended
from a wire.

Dimples would achieve roughly the same effect as the
circular trip wire.

Carl Fogel

Most frames have cables running the length of the down tube. I wonder if
they would have the same effect?
I suppose John Cobb will tell us one day.

Marty

"James Thomson" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Marty Wallace said:

With dimples being the latest fad in wheels and helmets,
are there any dimpled frames out there?

Oh yes.

http://www.hillbrick.com.au/graphics/xlr8r.gif

http://www.hillbrick.com.au/frames/frames_xlr8r.html

http://www.cyclingnews.com/photos/2002/tradeshows02/baus02/DSCN5106.jpg

I quote:

Multishape Damping Effect

XLR8R tubes only can be particularly shaped to obtain a sensible
damping effect of vibration phenomena. The idea is to use a shape
dam on the tube surface in order to damp vibrations in the frame.
This damp effect is obtained by creating three different diameter
punches, on both sides of the top and down tube ends, near the
head tube connection area. The punches are positioned in a zone
where the vibrations coming from the fork enter the frame structure.
Their particular shape enables the vibration dampening in two ways:

1. By creating a physical obstacle to the free movement of the
vibration waves along the tube

2. The emispheric shape of the punches enables the dissipation
of the vibration energy.

Columbus R&D dept. has made severe and repeated tests to define
the dimension and position of the punches and to check the damping
effect. Thanks to this Multishape damping effect, Columbus studies
proved that the vibration phenomena on XLR8R frames come up at
higher average speed than usual.

This is the formula of its success

I'm convinced.

James Thomson

The question was really asked with aerodynamics in mind.

Marty

Marty Wallace said:

The question was really asked with aerodynamics in mind.

The answer was given with divagation in mind, and without particular regard
for the intentions of the questioner.

Cordially,

James Thomson

Well, Carl, what would you think about tires whose tread resembles a golf
ball surface? I think this might actually work, especially considering that
the top of the tire is travelling at twice the bike speed.