Opinions on REI brand bikes (Novara)?



R

RonSonic

Guest
On Wed, 22 Mar 2006 08:54:59 -0600, Tim McNamara <[email protected]> wrote:

>In article <[email protected]>,
> jim beam <[email protected]> wrote:
>
>> how was i able to sniff out your desire to try picking a fight tim?
>> when you're ready to talk engineering [which you're clearly not right
>> now] get back to me. otherwise, you know what you can do. byeee!

>
>jim, jim, jim. Quell your paranoia. There's no attempt to pick a fight
>here. What you posted made no sense to me and appeared to be self
>contradictory, and I asked for clarification. However, to the
>adversarial person everyone looks like an adversary.
>
>Bicycle frames have no significant vertical flex, which is what would
>typically be discussed in terms of ride feel.


Why do you say that?

In fact, why do so many of these discussions get stupid over someone's theory or
lack of a theory.

There is no reason on earth for you to think that vertical fles would be the
thing discussed in terms of ride feel. Of course there's little vertical flex in
classic bike frame, everybody here knows that, so for some reason that's what
you want to talk about.

My present GT mountain bike is a buzzing PITA on pavement. My previous bike,
built with entirely the same parts, including tires, was not. The one before
that was downright smooth. None of these frames had any significant vertical
flex, of course.

How about a new theory - since we all agree that vertical flex isn't a factor.

Ron


>Geometry, specifically wheelbase and front and rear centers, are the
>primary frame qualities that affect road feel, along with tire inflation
>being probably a larger contributor. Invariably the bikes I hear of
>being described as "harsh" have a short rear center and rock hard 700 x
>23 tires. Material has little if anything to do with it, as comparing a
>Cannondale CAAD-whatever with a Vitus 979 will show. As I recall, you
>have pointed out all of those things yourself in the past.
>
>Pretty hard to pick a fight with you when we seem to be in agreement.
>
>You have typically been interested in lateral forces on wheels and such,
>so perhaps this is what are are referring to. Bike frames do have some
>lateral flex, since they are not triangulated in the direction, except
>in the case of the Dursley-Pedersen and Moulton designs. Whether that
>flex is significant is of some debate. If bike frames are springs and
>have no damping and return all of their energy, then it follows that
>lateral flex is not significant in terms of pedaling efficiency. There
>is, of course, also the issue of lateral flex in shimmy.
>
>Now, if you want to propose that lateral flex affects how a bike feels
>to ride, I'd have to ponder that. I haven't noticed it myself (except
>in shimmy-prone bikes), but I do know of some people who think this is
>the case and they are not prone to being crazy. Some find more
>laterally rigid frames better to ride, some find more flexible frames
>better to ride. So, while I haven't noticed that lateral flex makes a
>difference I guess that doesn't mean that there are not more sensitive
>people who do.
>
>It's too bad that you are so adversarial that you see everything as a
>fight. When I disagree with you, you'll know it. I'll put it in no
>uncertain terms and you won't have to sniff anything out.
 
J

John Forrest Tomlinson

Guest
On Thu, 23 Mar 2006 00:43:26 GMT, RonSonic <[email protected]>
wrote:


>There is no reason on earth for you to think that vertical fles would be the
>thing discussed in terms of ride feel. Of course there's little vertical flex in
>classic bike frame, everybody here knows that, so for some reason that's what
>you want to talk about.
>
>My present GT mountain bike is a buzzing PITA on pavement. My previous bike,
>built with entirely the same parts, including tires, was not. The one before
>that was downright smooth. None of these frames had any significant vertical
>flex, of course.
>
>How about a new theory - since we all agree that vertical flex isn't a factor.


I can offer two possible explanations.
1Somehow the two bikes sound different and that leads you to imgaine
they feel different
2 You just imagine they feel different
3 The saddle is stretching and getting softer with use.

Different frames for sure can feel different in hard pedalling and
cornering.

JT

****************************
Remove "remove" to reply
Visit http://www.jt10000.com
****************************
 
T

Tim McNamara

Guest
In article <[email protected]>,
Michael Press <[email protected]> wrote:

> In article <[email protected]>,
> Tim McNamara <[email protected]> wrote:
>
> > Bicycle frames have no significant vertical flex, which is what
> > would typically be discussed in terms of ride feel.

>
> Actually they can. A steel fork with thinly tapered blades, and small
> radius of curvature to provide fork offset will visibly flex over
> road irregularities. This is sometimes overlooked, and why straight
> blade forks look odd to a few of us.


When you look down at your front axle, you are not in a good position to
tell whether the fork is flexing vertically. There's enough noise in
the signal when looking at someone else's fork that it's impossible to
tell reliably. AFAIK there aren't any measurements of this, although
one could rig something up with strain gauges I suppose.

Straight blades just look odd to those of us old enough to have grown up
before BMX bike became popular, back when just about every fork you'd
ever see had a tight, small radius curve.
 
O

Ozark Bicycle

Guest
Michael Press wrote:
> In article
> <[email protected]>,
> "Ozark Bicycle" <[email protected]>
> wrote:
>
> > Dane Buson wrote:
> > > In rec.bicycles.misc Ozark Bicycle <[email protected]> wrote:
> > > >
> > > > Dane Buson wrote:
> > > >> In rec.bicycles.misc Ozark Bicycle <[email protected]> wrote:
> > > >> >
> > > >> > Ah! Charging a premium for using cane sugar syrup. The final piece of
> > > >> > the Coke/New Coke/Coke Classic gambit pays off at long last.
> > > >>
> > > >> You think too small, it's obviously part of the international Communist
> > > >> conspiracy to sap and impurify all of our precious bodily fluids.
> > > >> That's why I drink only distilled water, or rain water, and only pure
> > > >> grain alcohol.
> > > >
> > > > But, do you deny women your essence?
> > >
> > > Sometimes I have felt a profound sense of fatigue, a feeling of emptiness.
> > > Luckily I was able to interpret these feelings correctly: loss of essence. I
> > > can assure you it has not recurred, Ozark.
> > >
> > >

> >
> > Did you ever watch "Fail Safe" and then "Dr. Strangelove" as a double
> > feature? It's very interesting....

>
> The humor in Fail Safe eludes me.
>
>


That's part of what the Kubrick/Southern sceenplay for "Strangelove"
was about; a sendup of the deadly serious "Fail Safe".


>
> President Merkin Muffley: General Turgidson, I find this
> very difficult to understand. I was under the impression
> that I was the only one in authority to order the use of
> nuclear weapons.
>
> General "Buck" Turgidson: That's right, sir, you are the
> only person authorized to do so. And although I, uh, hate
> to judge before all the facts are in, it's beginning to
> look like, uh, General Ripper exceeded his authority.
>
> --
> Michael Press
 
O

Ozark Bicycle

Guest
John Forrest Tomlinson wrote:
> On Thu, 23 Mar 2006 00:43:26 GMT, RonSonic <[email protected]>
> wrote:
>
>
> >There is no reason on earth for you to think that vertical fles would be the
> >thing discussed in terms of ride feel. Of course there's little vertical flex in
> >classic bike frame, everybody here knows that, so for some reason that's what
> >you want to talk about.
> >
> >My present GT mountain bike is a buzzing PITA on pavement. My previous bike,
> >built with entirely the same parts, including tires, was not. The one before
> >that was downright smooth. None of these frames had any significant vertical
> >flex, of course.
> >
> >How about a new theory - since we all agree that vertical flex isn't a factor.

>
> I can offer two possible explanations.
> 1Somehow the two bikes sound different and that leads you to imgaine
> they feel different



IMO, that's a big factor.



> 2 You just imagine they feel different



An even bigger factor. Never discount expectation effects, the placebo
effect, etc.


> 3 The saddle is stretching and getting softer with use.
>


Nah.
 
D

dvt

Guest
RonSonic wrote:
> On Wed, 22 Mar 2006 08:54:59 -0600, Tim McNamara <[email protected]> wrote:


>> Bicycle frames have no significant vertical flex, which is what would
>> typically be discussed in terms of ride feel.


> There is no reason on earth for you to think that vertical fles would be the
> thing discussed in terms of ride feel. Of course there's little vertical flex in
> classic bike frame...


> My present GT mountain bike is a buzzing PITA on pavement. My previous bike,
> built with entirely the same parts, including tires, was not. The one before
> that was downright smooth. None of these frames had any significant vertical
> flex, of course.


> How about a new theory - since we all agree that vertical flex isn't a factor.


Tim has already proposed a few potential explanations, and you quoted it
in your post. I repeat that part of Tim's post here:

>> Geometry, specifically wheelbase and front and rear centers, are the
>> primary frame qualities that affect road feel, along with tire inflation
>> being probably a larger contributor. Invariably the bikes I hear of
>> being described as "harsh" have a short rear center and rock hard 700 x
>> 23 tires.


I suspect that if you had all of the dimensions of the three bikes you
mention, you would see some differences. Short chainstays might be high
on the list, but I'll bet there are other factors in the geometry that
contribute to ride quality, too.

--
Dave
dvt at psu dot edu
 
R

RonSonic

Guest
On Thu, 23 Mar 2006 00:21:27 GMT, Michael Press <[email protected]> wrote:

>In article
><[email protected]>,
> "Ozark Bicycle" <[email protected]>
> wrote:
>
>> Dane Buson wrote:
>> > In rec.bicycles.misc Ozark Bicycle <[email protected]> wrote:
>> > >
>> > > Dane Buson wrote:
>> > >> In rec.bicycles.misc Ozark Bicycle <[email protected]> wrote:
>> > >> >
>> > >> > Ah! Charging a premium for using cane sugar syrup. The final piece of
>> > >> > the Coke/New Coke/Coke Classic gambit pays off at long last.
>> > >>
>> > >> You think too small, it's obviously part of the international Communist
>> > >> conspiracy to sap and impurify all of our precious bodily fluids.
>> > >> That's why I drink only distilled water, or rain water, and only pure
>> > >> grain alcohol.
>> > >
>> > > But, do you deny women your essence?
>> >
>> > Sometimes I have felt a profound sense of fatigue, a feeling of emptiness.
>> > Luckily I was able to interpret these feelings correctly: loss of essence. I
>> > can assure you it has not recurred, Ozark.
>> >
>> >

>>
>> Did you ever watch "Fail Safe" and then "Dr. Strangelove" as a double
>> feature? It's very interesting....

>
>The humor in Fail Safe eludes me.


The absolute silliness of the setup, 32 things that don't even exist go wrong to
lead us to the complete absurdity of President Fonda's solution. It was the
stupidest thing on film before the release of Battlefield Earth. It was very
well acted, directed and edited, that was a first rate job of film making. Just
a wet yourself laughing plot of staggering improbability.

>
> *****
>
>President Merkin Muffley: General Turgidson, I find this
>very difficult to understand. I was under the impression
>that I was the only one in authority to order the use of
>nuclear weapons.
>
>General "Buck" Turgidson: That's right, sir, you are the
>only person authorized to do so. And although I, uh, hate
>to judge before all the facts are in, it's beginning to
>look like, uh, General Ripper exceeded his authority.
 
R

RonSonic

Guest
On Wed, 22 Mar 2006 20:14:43 -0500, John Forrest Tomlinson
<[email protected]> wrote:

>On Thu, 23 Mar 2006 00:43:26 GMT, RonSonic <[email protected]>
>wrote:
>
>
>>There is no reason on earth for you to think that vertical fles would be the
>>thing discussed in terms of ride feel. Of course there's little vertical flex in
>>classic bike frame, everybody here knows that, so for some reason that's what
>>you want to talk about.
>>
>>My present GT mountain bike is a buzzing PITA on pavement. My previous bike,
>>built with entirely the same parts, including tires, was not. The one before
>>that was downright smooth. None of these frames had any significant vertical
>>flex, of course.
>>
>>How about a new theory - since we all agree that vertical flex isn't a factor.

>
>I can offer two possible explanations.
>1Somehow the two bikes sound different and that leads you to imgaine
>they feel different


Okay, it sounds different. Actually, I knew that before I built it up. Try this
on for size, we are sitting on things that sound. Sound is vibration in the air,
usually stimulated by a solid object that VIBRATES.

Different objects, like bike frames vibrate differently.

Things that vibrate differently are likely to feel different when you SIT on
them.

>2 You just imagine they feel different
>3 The saddle is stretching and getting softer with use.
>
>Different frames for sure can feel different in hard pedalling and
>cornering.


They can just feel different in all sorts of ways. I'm really getting irritated
at the mindset that claims that a phenomenon cannot exist because we don't have
a theory to explain it.

Ron
 
R

RonSonic

Guest
On 22 Mar 2006 18:56:52 -0800, "Ozark Bicycle"
<[email protected]> wrote:

>
>Michael Press wrote:
>> In article
>> <[email protected]>,
>> "Ozark Bicycle" <[email protected]>
>> wrote:
>>
>> > Dane Buson wrote:
>> > > In rec.bicycles.misc Ozark Bicycle <[email protected]> wrote:
>> > > >
>> > > > Dane Buson wrote:
>> > > >> In rec.bicycles.misc Ozark Bicycle <[email protected]> wrote:
>> > > >> >
>> > > >> > Ah! Charging a premium for using cane sugar syrup. The final piece of
>> > > >> > the Coke/New Coke/Coke Classic gambit pays off at long last.
>> > > >>
>> > > >> You think too small, it's obviously part of the international Communist
>> > > >> conspiracy to sap and impurify all of our precious bodily fluids.
>> > > >> That's why I drink only distilled water, or rain water, and only pure
>> > > >> grain alcohol.
>> > > >
>> > > > But, do you deny women your essence?
>> > >
>> > > Sometimes I have felt a profound sense of fatigue, a feeling of emptiness.
>> > > Luckily I was able to interpret these feelings correctly: loss of essence. I
>> > > can assure you it has not recurred, Ozark.
>> > >
>> > >
>> >
>> > Did you ever watch "Fail Safe" and then "Dr. Strangelove" as a double
>> > feature? It's very interesting....

>>
>> The humor in Fail Safe eludes me.
>>
>>

>
>That's part of what the Kubrick/Southern sceenplay for "Strangelove"
>was about; a sendup of the deadly serious "Fail Safe".


"Deadly serious" is far too kind.

"Portentous, over-blown, melodramatic, pretentious, self-important, absurd and
inadvertently comical in a way that would later make Leslie Nielsen rich" would
be a little closer to the mark.

Ron
 
M

Mark Janeba

Guest
RonSonic wrote:
> On 22 Mar 2006 18:56:52 -0800, "Ozark Bicycle"
> <[email protected]> wrote:
>
>
>>Michael Press wrote:
>>
>>>In article
>>><[email protected]>,
>>> "Ozark Bicycle" <[email protected]>
>>> wrote:
>>>
>>>
>>>>Dane Buson wrote:
>>>>
>>>>>In rec.bicycles.misc Ozark Bicycle <[email protected]> wrote:
>>>>>
>>>>>>Dane Buson wrote:
>>>>>>
>>>>>>>In rec.bicycles.misc Ozark Bicycle <[email protected]> wrote:
>>>>>>>
>>>>>>>>Ah! Charging a premium for using cane sugar syrup. The final piece of
>>>>>>>>the Coke/New Coke/Coke Classic gambit pays off at long last.
>>>>>>>
>>>>>>>You think too small, it's obviously part of the international Communist
>>>>>>>conspiracy to sap and impurify all of our precious bodily fluids.
>>>>>>>That's why I drink only distilled water, or rain water, and only pure
>>>>>>>grain alcohol.
>>>>>>
>>>>>>But, do you deny women your essence?
>>>>>
>>>>>Sometimes I have felt a profound sense of fatigue, a feeling of emptiness.
>>>>>Luckily I was able to interpret these feelings correctly: loss of essence. I
>>>>>can assure you it has not recurred, Ozark.
>>>>>
>>>>>
>>>>
>>>>Did you ever watch "Fail Safe" and then "Dr. Strangelove" as a double
>>>>feature? It's very interesting....
>>>
>>>The humor in Fail Safe eludes me.
>>>
>>>

>>
>>That's part of what the Kubrick/Southern sceenplay for "Strangelove"
>>was about; a sendup of the deadly serious "Fail Safe".

>
>
> "Deadly serious" is far too kind.
>
> "Portentous, over-blown, melodramatic, pretentious, self-important, absurd and
> inadvertently comical in a way that would later make Leslie Nielsen rich" would
> be a little closer to the mark.


If we're going to be literal about technical details of a nuclear strike
in the 50's, then perhaps yes; it's been far too long since I've seen
Fail Safe to tell. However, if the goal is to address the possibility
of an accidentally launched nuclear strike, it comes much closer to the
mark. Reread the history of near-accidents (by both the US and soviets)
in the 80's. The primary difference being that by the 80's, the time
between launch and impact is down to ~20 minutes rather than a few hours.

If the final resolution of Fail Safe is too absurd for you, perhaps
that's the author's point - that the nuclear balance of terror and
Mutually Assured Destruction was/is absurd.

Mark
 
A

Alan Hoyle

Guest
On Thu, 23 Mar 2006 06:50:54 -0800, Mark Janeba wrote:

> If we're going to be literal about technical details of a nuclear strike
> in the 50's, then perhaps yes; it's been far too long since I've seen
> Fail Safe to tell. However, if the goal is to address the possibility
> of an accidentally launched nuclear strike, it comes much closer to the
> mark. Reread the history of near-accidents (by both the US and soviets)
> in the 80's. The primary difference being that by the 80's, the time
> between launch and impact is down to ~20 minutes rather than a few hours.


> If the final resolution of Fail Safe is too absurd for you, perhaps
> that's the author's point - that the nuclear balance of terror and
> Mutually Assured Destruction was/is absurd.


For reference, Dr Strangelove was released on January 29, 1964
(http://www.imdb.com/title/tt0057012/releaseinfo), Fail Safe was
October 7, 1964 (http://www.imdb.com/title/tt0058083/releaseinfo).

-alan

--
Alan Hoyle - [email protected] - http://www.alanhoyle.com/
"I don't want the world, I just want your half." -TMBG
Get Horizontal, Play Ultimate.
 
D

Dave Larrington

Guest
In article <[email protected]>, Alan Hoyle ([email protected])
wrote:
> On Thu, 23 Mar 2006 06:50:54 -0800, Mark Janeba wrote:
>
> > If we're going to be literal about technical details of a nuclear strike
> > in the 50's, then perhaps yes; it's been far too long since I've seen
> > Fail Safe to tell. However, if the goal is to address the possibility
> > of an accidentally launched nuclear strike, it comes much closer to the
> > mark. Reread the history of near-accidents (by both the US and soviets)
> > in the 80's. The primary difference being that by the 80's, the time
> > between launch and impact is down to ~20 minutes rather than a few hours.

>
> > If the final resolution of Fail Safe is too absurd for you, perhaps
> > that's the author's point - that the nuclear balance of terror and
> > Mutually Assured Destruction was/is absurd.

>
> For reference, Dr Strangelove was released on January 29, 1964
> (http://www.imdb.com/title/tt0057012/releaseinfo), Fail Safe was
> October 7, 1964 (http://www.imdb.com/title/tt0058083/releaseinfo).


And "Fail Safe" was first *published* in 1962.

--
Dave Larrington - <http://www.legslarry.beerdrinkers.co.uk/>
Ernesto, give me that Kit-Kat, or I will kill you.
 
M

Mike Reed

Guest
Tim McNamara wrote:
> Now, if you want to propose that lateral flex affects how a bike feels
> to ride, I'd have to ponder that. I haven't noticed it myself (except
> in shimmy-prone bikes), but I do know of some people who think this is
> the case and they are not prone to being crazy. Some find more
> laterally rigid frames better to ride, some find more flexible frames
> better to ride. So, while I haven't noticed that lateral flex makes a
> difference I guess that doesn't mean that there are not more sensitive
> people who do.


I was thinking about this last night. I have a theory that lateral
frame flex dampens the bumps as felt through our feet, not our rumps.
When you are pedalling, some percentage of your weight is supported by
your feet through the cranks. Given that q-factor is nonzero, we are
pushing a lever displaced laterally from the center of the frame, and
it's not symmetrically supported if we're under power (only one pedal
is resisting that force). If there is lateral flex, the pedalling
action will work the flex. This would soften the bumps.

Thoughts?
 
O

Ozark Bicycle

Guest
Alan Hoyle wrote:
> On Thu, 23 Mar 2006 06:50:54 -0800, Mark Janeba wrote:
>
> > If we're going to be literal about technical details of a nuclear strike
> > in the 50's, then perhaps yes; it's been far too long since I've seen
> > Fail Safe to tell. However, if the goal is to address the possibility
> > of an accidentally launched nuclear strike, it comes much closer to the
> > mark. Reread the history of near-accidents (by both the US and soviets)
> > in the 80's. The primary difference being that by the 80's, the time
> > between launch and impact is down to ~20 minutes rather than a few hours.

>
> > If the final resolution of Fail Safe is too absurd for you, perhaps
> > that's the author's point - that the nuclear balance of terror and
> > Mutually Assured Destruction was/is absurd.

>
> For reference, Dr Strangelove was released on January 29, 1964
> (http://www.imdb.com/title/tt0057012/releaseinfo), Fail Safe was
> October 7, 1964 (http://www.imdb.com/title/tt0058083/releaseinfo).
>
>


Yes, and as I recall, "Dr.Strangelove" the film was intended as a
sendup of "Fail Safe" the book.
 
T

Tim McNamara

Guest
In article <[email protected]>,
"Mike Reed" <[email protected]> wrote:

> Tim McNamara wrote:
> > Now, if you want to propose that lateral flex affects how a bike
> > feels to ride, I'd have to ponder that. I haven't noticed it
> > myself (except in shimmy-prone bikes), but I do know of some people
> > who think this is the case and they are not prone to being crazy.
> > Some find more laterally rigid frames better to ride, some find
> > more flexible frames better to ride. So, while I haven't noticed
> > that lateral flex makes a difference I guess that doesn't mean that
> > there are not more sensitive people who do.

>
> I was thinking about this last night. I have a theory that lateral
> frame flex dampens the bumps as felt through our feet, not our rumps.
> When you are pedalling, some percentage of your weight is supported
> by your feet through the cranks. Given that q-factor is nonzero, we
> are pushing a lever displaced laterally from the center of the frame,
> and it's not symmetrically supported if we're under power (only one
> pedal is resisting that force). If there is lateral flex, the
> pedalling action will work the flex. This would soften the bumps.


My first through is "hmmm." My second thought is that if one stands
with one's weight equally on each pedal, the effect would be cancelled
out. My third thought is that if one coasts standing on one leg, maybe.
While pedaling, weight distribution alternates mostly (we usually have
some weight on the riding pedal), so "maybe." I'll go back to my first
thought: "hmmm."

Of course, there is more to "ride feel" than riding over bumps. There's
also how the bike feels accelerating out of corners or pedaling through
corners, as JT mentioned. The feel of the bike is different- or rather
we perceive different information about the bike- if we are pedaling and
being motorically active than if we are passively coasting. I imagine
that JT and jim would both point out that the lateral flex properties of
the bike don't come into play when coasting, for example.
 
M

Mike Reed

Guest
Tim McNamara wrote:
> In article <[email protected]>,
> "Mike Reed" <[email protected]> wrote:
>
> > Tim McNamara wrote:
> > > Now, if you want to propose that lateral flex affects how a bike
> > > feels to ride, I'd have to ponder that. I haven't noticed it
> > > myself (except in shimmy-prone bikes), but I do know of some people
> > > who think this is the case and they are not prone to being crazy.
> > > Some find more laterally rigid frames better to ride, some find
> > > more flexible frames better to ride. So, while I haven't noticed
> > > that lateral flex makes a difference I guess that doesn't mean that
> > > there are not more sensitive people who do.

> >
> > I was thinking about this last night. I have a theory that lateral
> > frame flex dampens the bumps as felt through our feet, not our rumps.
> > When you are pedalling, some percentage of your weight is supported
> > by your feet through the cranks. Given that q-factor is nonzero, we
> > are pushing a lever displaced laterally from the center of the frame,
> > and it's not symmetrically supported if we're under power (only one
> > pedal is resisting that force). If there is lateral flex, the
> > pedalling action will work the flex. This would soften the bumps.

>
> My first through is "hmmm." My second thought is that if one stands
> with one's weight equally on each pedal, the effect would be cancelled
> out. My third thought is that if one coasts standing on one leg, maybe.
> While pedaling, weight distribution alternates mostly (we usually have
> some weight on the riding pedal), so "maybe." I'll go back to my first
> thought: "hmmm."
>
> Of course, there is more to "ride feel" than riding over bumps. There's
> also how the bike feels accelerating out of corners or pedaling through
> corners, as JT mentioned. The feel of the bike is different- or rather
> we perceive different information about the bike- if we are pedaling and
> being motorically active than if we are passively coasting. I imagine
> that JT and jim would both point out that the lateral flex properties of
> the bike don't come into play when coasting, for example.


Yeah, my theory only applies when you're under power, and you've got
more power on the downstroke than on the upstroke.

-Mike
 
P

Patrick Lamb

Guest
On Thu, 23 Mar 2006 13:53:56 GMT, RonSonic <[email protected]>
wrote:
>On Wed, 22 Mar 2006 20:14:43 -0500, John Forrest Tomlinson
><[email protected]> wrote:
>
>>On Thu, 23 Mar 2006 00:43:26 GMT, RonSonic <[email protected]>
>>wrote:
>>
>>>There is no reason on earth for you to think that vertical fles would be the
>>>thing discussed in terms of ride feel. Of course there's little vertical flex in
>>>classic bike frame, everybody here knows that, so for some reason that's what
>>>you want to talk about.
>>>
>>>My present GT mountain bike is a buzzing PITA on pavement. My previous bike,
>>>built with entirely the same parts, including tires, was not. The one before
>>>that was downright smooth. None of these frames had any significant vertical
>>>flex, of course.
>>>
>>>How about a new theory - since we all agree that vertical flex isn't a factor.

>>
>>I can offer two possible explanations.
>>1Somehow the two bikes sound different and that leads you to imgaine
>>they feel different

>
>Okay, it sounds different. Actually, I knew that before I built it up. Try this
>on for size, we are sitting on things that sound. Sound is vibration in the air,
>usually stimulated by a solid object that VIBRATES.
>
>Different objects, like bike frames vibrate differently.
>
>Things that vibrate differently are likely to feel different when you SIT on
>them.


I get the feeling that you're grasping at straws here. Vibrations you
can hear are usually above 100 Hz, probably above 150-200 Hz.
Vibrations you can feel are normally below that frequency.

Pat

Email address works as is.
 
R

RonSonic

Guest
On Thu, 23 Mar 2006 21:49:26 -0600, Patrick Lamb <[email protected]>
wrote:

>On Thu, 23 Mar 2006 13:53:56 GMT, RonSonic <ronson[email protected]>
>wrote:
>>On Wed, 22 Mar 2006 20:14:43 -0500, John Forrest Tomlinson
>><[email protected]> wrote:
>>
>>>On Thu, 23 Mar 2006 00:43:26 GMT, RonSonic <[email protected]>
>>>wrote:
>>>
>>>>There is no reason on earth for you to think that vertical fles would be the
>>>>thing discussed in terms of ride feel. Of course there's little vertical flex in
>>>>classic bike frame, everybody here knows that, so for some reason that's what
>>>>you want to talk about.
>>>>
>>>>My present GT mountain bike is a buzzing PITA on pavement. My previous bike,
>>>>built with entirely the same parts, including tires, was not. The one before
>>>>that was downright smooth. None of these frames had any significant vertical
>>>>flex, of course.
>>>>
>>>>How about a new theory - since we all agree that vertical flex isn't a factor.
>>>
>>>I can offer two possible explanations.
>>>1Somehow the two bikes sound different and that leads you to imgaine
>>>they feel different

>>
>>Okay, it sounds different. Actually, I knew that before I built it up. Try this
>>on for size, we are sitting on things that sound. Sound is vibration in the air,
>>usually stimulated by a solid object that VIBRATES.
>>
>>Different objects, like bike frames vibrate differently.
>>
>>Things that vibrate differently are likely to feel different when you SIT on
>>them.

>
>I get the feeling that you're grasping at straws here. Vibrations you
>can hear are usually above 100 Hz, probably above 150-200 Hz.
>Vibrations you can feel are normally below that frequency.


Grasping at.... ?!?!?!

This is the most obvious thing in the world to me. This is like me telling you
that there is no pink. If you don't think that vibrations you can hear are
related to vibrations you can feel sit on a speaker cabinet. Mount a bicycle
seat on one if you really want to go nuts on this. Run signal. Do sweeps of
various parts of the frequency range. Run sine, square, whatever sort of wave
form you like. Do we need to strap a frame to a shaker table and torture some
schmuck, before you'll believe what you feel?

There is a huge crossover range between what is felt and heard. There's an even
larger range in which shock will excite a resonant structure of metal tubes.

I am just astonished at this rigorous adherence to dogma. Listen and feel. Use
your freeking senses. Your lack of a theory to explain it does NOT invalidate
observation.

Ron
 
RonSonic wrote:
> On Thu, 23 Mar 2006 21:49:26 -0600, Patrick Lamb <[email protected]>
> wrote:
>
> >I get the feeling that you're grasping at straws here. Vibrations you
> >can hear are usually above 100 Hz, probably above 150-200 Hz.
> >Vibrations you can feel are normally below that frequency.

>
> Grasping at.... ?!?!?!
>
> This is the most obvious thing in the world to me. This is like me telling you
> that there is no pink. If you don't think that vibrations you can hear are
> related to vibrations you can feel sit on a speaker cabinet. Mount a bicycle
> seat on one if you really want to go nuts on this.


Ron, have you actually tried mounting a bike seat on a speaker cabinet?
Do you _seriously_ think your butt would be able to feel the
vibrations to any significant degree?

I think you should do some reading on vibration isolation. Flexible
structures like seats, supporting large masses like riders' butts,
can't transmit high frequency vibrations very effectively. The natural
frequency of the seat-butt system is too low, and this frequency
mismatch is responsible for the isolation. This is why motor mounts are
flexible.

> Run signal. Do sweeps of
> various parts of the frequency range. Run sine, square, whatever sort of wave
> form you like. Do we need to strap a frame to a shaker table and torture some
> schmuck, before you'll believe what you feel?


Again - have you actually done this? If Patrick felt what you're
describing, there are a lot of mechanical vibration textbooks that
would need re-writing.


- Frank Krygowski
 
M

Mike Reed

Guest
[email protected] wrote:
> Flexible
> structures like seats, supporting large masses like riders' butts,
> can't transmit high frequency vibrations very effectively.


It's amplitude, not frequency that you'll feel through a seat. Think
about a high frequency (100Hz?) jackhammer. Think you might feel that
through a seat?

-Mike