How real is a tall head tube to ride?
 

With Paris-Roubaix, everyone's talking about the value of "relaxed"
frame geometry again, specifically the long head tube and the benefits
they bring.

My question is, what ride differences are there b/n a frame with a
longer head tube and a regular road frame that has more spacers inserted
below the stem, thereby achieving a longer virtual head tube?

I've asked this question a number of times elsewhere and no one seemed
to be able to answer it directly.
--

How real is a tall head tube to ride?
 

"Artoi" wrote in message
...
With Paris-Roubaix, everyone's talking about the value of "relaxed"
frame geometry again, specifically the long head tube and the benefits
they bring.

My question is, what ride differences are there b/n a frame with a
longer head tube and a regular road frame that has more spacers
inserted
below the stem, thereby achieving a longer virtual head tube?

I've asked this question a number of times elsewhere and no one seemed
to be able to answer it directly.
--
I've never ridden cobbles very far but for normal road riding a longer
head tube will result in a frame that is torsionally softer. Think of a
twisted frame with the top tube and down tube out of plane. A shorter
head tube is torsionally stiffer than a long head tube and will resist
this kind of flex.

The closer the top tube is to the down tube where they connect to the
head tube, the stiffer the frame (all other things being equal). Adding
spacers will achieve a taller geometry without affecting frame flex and
handling.

The worst affect of torsional flexing is in the handling of the bike
where the wheels go out of alignment (head tube out of plane with seat
tube) and the bike does not track well.

Phil H

How real is a tall head tube to ride?
 

that's relaxed carbon tube geometry? tall head tube geometry? tall?
what does tall have to do with geometry? the angle determines
geometry.
would seem the rear lever from longer seat tube vastly overpowers
effects at the realtively shgort, nay fractional comparable lengths up
at the head tube.
anyway, its carbon right? who knows ???
you ask a good question.
spacers? (forgive me being an *&&&**) "Adding
spacers will achieve a taller geometry without affecting frame flex
and
handling. "
adding spacers automatically adds flex everywhere.
spacers, as geometry ? hmmmm
non-euclidean ? reimann space effetc?
anyway ignore this post.
gibberish

How real is a tall head tube to ride?
 

In article ,
Artoi wrote:

With Paris-Roubaix, everyone's talking about the value of "relaxed"
frame geometry again, specifically the long head tube and the
benefits they bring.

My question is, what ride differences are there b/n a frame with a
longer head tube and a regular road frame that has more spacers
inserted below the stem, thereby achieving a longer virtual head
tube?

I've asked this question a number of times elsewhere and no one
seemed to be able to answer it directly. --

It's hard to answer because it doesn't entirely make sense, especially
since I haven't seen any of these discussions about "relaxed" frame
geometry, long head tubes, etc. IMHO the benefit is making the bike fit
your particular dimensions for your particular purpose. At 6'4" and 215
pounds, I ride bikes ranging from 60 cm to 64 cm center-to-top. One has
"laid back" geometry (72/72), one has "neutral" geometry (73/73.5) and
one has a mix (74/72.5) (all parenthetical angles are head/seat tube).

Do I notice a huge difference switching from bike to bike. No, and what
difference I notice is only for about a minute when I start riding.

In terms of fit, it's easiest to get the tallest of the bikes adjusted
to fit me comfortably. The smaller frames make it hard to get the bars
up high enough to be comfortable on long rides (about 2 cm below the
saddle). I have stems with long quills as a result and they look a
little odd. Back when I raced I had the bars 6-8 cm below the saddle
for aerodynamics and the smaller frames made that easier to achieve.

Paris-Roubaix is an unrealistic yardstick. Few of us spend our days
hurtling as fast as we can across ancient cobblestones covered in
manure. Most of us might ride on a gravel road or have to contend with
the failing American infrastructure bequeathed to us by nearly three
decades of anti-government anti-tax arrant nonsense. Fatter tires would
be a better investment than relaxed geometry and long head tubes...

How real is a tall head tube to ride?
 

right better tires does it.
try your quick frame shod (eeyaqyayahaha "shod') shod with mitty
racing tires. ride on a narrow berm over sand, amacite, sand, grass/
sand gloosy tar whathaveyou? during rush hour and the quick geometry
becomes ahhhpparent.
continuing sudden changes in grip exaggerate each geometry.
Imagine sand sprinkled over ice would do similar
you know lika skid pad.

How real is a tall head tube to ride?
 

In article ,
"Phil Holman" piholmanc@yourservice wrote:

"Artoi" wrote in message
...
With Paris-Roubaix, everyone's talking about the value of "relaxed"
frame geometry again, specifically the long head tube and the benefits
they bring.

My question is, what ride differences are there b/n a frame with a
longer head tube and a regular road frame that has more spacers
inserted
below the stem, thereby achieving a longer virtual head tube?

I've asked this question a number of times elsewhere and no one seemed
to be able to answer it directly.
--
I've never ridden cobbles very far but for normal road riding a longer
head tube will result in a frame that is torsionally softer. Think of a
twisted frame with the top tube and down tube out of plane. A shorter
head tube is torsionally stiffer than a long head tube and will resist
this kind of flex.

The closer the top tube is to the down tube where they connect to the
head tube, the stiffer the frame (all other things being equal). Adding
spacers will achieve a taller geometry without affecting frame flex and
handling.

The worst affect of torsional flexing is in the handling of the bike
where the wheels go out of alignment (head tube out of plane with seat
tube) and the bike does not track well.

This makes sense. So in other words, what people/companies refers to as
"relaxed geometry" is actually one that is a torsionally less stiff
frame. Then the issue here is, why would it be considered to be more
comfortable? By comfortable I would have assumed its more vertically
compliant. Frames in this category include Giant's OCR range,
Specialized Roubaix range etc.
--

How real is a tall head tube to ride?
 

In article
,
datakoll wrote:

that's relaxed carbon tube geometry? tall head tube geometry? tall?
what does tall have to do with geometry? the angle determines
geometry.
would seem the rear lever from longer seat tube vastly overpowers
effects at the realtively shgort, nay fractional comparable lengths up
at the head tube.
anyway, its carbon right? who knows ???
you ask a good question.
spacers? (forgive me being an *&&&**) "Adding
spacers will achieve a taller geometry without affecting frame flex
and
handling. "
adding spacers automatically adds flex everywhere.
spacers, as geometry ? hmmmm
non-euclidean ? reimann space effetc?
anyway ignore this post.
gibberish

Well, not if you look at what those companies have to say about their
bike models like Giant's OCR and Specialized's Roubaix models. Even
Cervelo have a R3 SL model.

So irrespective whether the concept is gibberish, these statements are
real.
--

How real is a tall head tube to ride?
 

forks stuck in short head tubes move around easier, more flexibly,
than forks stuck in longer head tubes,
Zoooo given carbon characreistcs (whatever that is) trail increases
are handled best thru longer head tubes.
Prob also some rather esoteric computer generated human feed insanity
on pressure wavelength damping (PWD), sensory threshold cobblestone
impact absorption quotients. The usual smoke:
Our equipment runs downhill and floats, your crap runs uphill and
sinks...

How real is a tall head tube to ride?
 

On Apr 16, 7:27 am, Artoi wrote:
In article ,
"Phil Holman" piholmanc@yourservice wrote:



"Artoi" wrote in message
...
With Paris-Roubaix, everyone's talking about the value of "relaxed"
frame geometry again, specifically the long head tube and the benefits
they bring.

My question is, what ride differences are there b/n a frame with a
longer head tube and a regular road frame that has more spacers
inserted
below the stem, thereby achieving a longer virtual head tube?

I've asked this question a number of times elsewhere and no one seemed
to be able to answer it directly.
--
I've never ridden cobbles very far but for normal road riding a longer
head tube will result in a frame that is torsionally softer. Think of a
twisted frame with the top tube and down tube out of plane. A shorter
head tube is torsionally stiffer than a long head tube and will resist
this kind of flex.

The closer the top tube is to the down tube where they connect to the
head tube, the stiffer the frame (all other things being equal). Adding
spacers will achieve a taller geometry without affecting frame flex and
handling.

The worst affect of torsional flexing is in the handling of the bike
where the wheels go out of alignment (head tube out of plane with seat
tube) and the bike does not track well.

This makes sense. So in other words, what people/companies refers to as
"relaxed geometry" is actually one that is a torsionally less stiff
frame. Then the issue here is, why would it be considered to be more
comfortable? By comfortable I would have assumed its more vertically
compliant. Frames in this category include Giant's OCR range,
Specialized Roubaix range etc.
--

Not really. Geometry only affects rider position and handling
dynamics. "Relaxed" generally means slacker tube angles to get the
rider's weight back and slow down steering. Any shaped frame can be
built to varying degrees of torsional stiffness, and vertical
compliance is a myth. The trend of adding taller head tubes is purely
for people who want higher bars without spacers.

How real is a tall head tube to ride?
 

On Wed, 16 Apr 2008 11:27:40 GMT, Artoi wrote:

In article ,
"Phil Holman" piholmanc@yourservice wrote:

"Artoi" wrote in message
...
With Paris-Roubaix, everyone's talking about the value of "relaxed"
frame geometry again, specifically the long head tube and the benefits
they bring.

My question is, what ride differences are there b/n a frame with a
longer head tube and a regular road frame that has more spacers
inserted
below the stem, thereby achieving a longer virtual head tube?

I've asked this question a number of times elsewhere and no one seemed
to be able to answer it directly.
--
I've never ridden cobbles very far but for normal road riding a longer
head tube will result in a frame that is torsionally softer. Think of a
twisted frame with the top tube and down tube out of plane. A shorter
head tube is torsionally stiffer than a long head tube and will resist
this kind of flex.

The closer the top tube is to the down tube where they connect to the
head tube, the stiffer the frame (all other things being equal). Adding
spacers will achieve a taller geometry without affecting frame flex and
handling.

The worst affect of torsional flexing is in the handling of the bike
where the wheels go out of alignment (head tube out of plane with seat
tube) and the bike does not track well.

This makes sense. So in other words, what people/companies refers to as
"relaxed geometry" is actually one that is a torsionally less stiff
frame. Then the issue here is, why would it be considered to be more
comfortable? By comfortable I would have assumed its more vertically
compliant. Frames in this category include Giant's OCR range,
Specialized Roubaix range etc.

The longer head tube causes the front triangle to not be a triangle. Instead of
having all tubes in tension/compression they are more in flexion. How big a
difference, probably not a hell of a lot. Enough to tell? Take that up with the
propellor heads who think that as long as it has pneumatic tires no change in
frame design could possibly make a difference.