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Main
Date: 11 Nov 2007 05:28:05
From:
Subject: MI5 Persecution: Flying Eye (Mar/1999) (3450)
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Jackie King from the Flying Eye 14/3/99
Certainty level: 40%
In early March 1999, Capital Radio alleged they had received some emails,
one of which was forwarded to me. It contained the words, "you know this
bloke, he says we're trying to kill him, we should be done for attempted
manslaughter!" which Chris Tarrant had said in 1994.
Following these emails there was an explosion in abuse activity, both from
Capital Radio, and from MI5 themselves. MI5 followed me around and hurled
abuse at me. The following audio file contains what may be abuse from the
radio station.
Jackie King from the Flying Eye made these remarks on Sunday (14/3/99)
lunchtime 12.24pm; "gas main work being, er, HANDLED if you like (laughs,
embarrassed) outside Madame Tussauds, Euston Road obviously feeling the
backlash of that".
The key word is "handled", which she sounds embarrassed to be saying; to
me it looks like an attempt at a sexual slander. Capital Radio aren't even
pretending not to get at me any more. I asked Chris Tarrant several times
about his remark from 1994, and he has consistently avoided answering.
3450
--
Posted via NewsDemon.com - Premium Uncensored Newsgroup Service
------- >>>>>>http://www.NewsDemon.com<<<<<<------
Unlimited Access, Anonymous Accounts, Uncensored Broadband Access
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Date: 11 Nov 2007 10:22:16
From: jim beam
Subject: Re: rear rim seems to rub
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Luns Tee wrote:
> In article <K_mdndLUKLJbXavanZ2dnUVZ_uevnZ2d@speakeasy.net>,
> jim beam <spamvortex@bad.example.net> wrote:
>>> This does not free you
>>> from having to consider the interaction between the arms.
>> but the "interaction" is simply that of centering. if you look at the
>> mechanism, it's not designed for any load other than the caliper's own
>> return spring. brake load is that of squeezing the the rim between the
>> "y" and "c" arms, and that can occur entirely without the centering action.
>
> How does the centering happen if not by transmitting a force
> where the Y and C arms meet? Your neglecting this force is the heart
> of why your conclusions are wrong.
but luns, the force on the centering pin is simply against the spring.
the y-arm can move independently. you could, if you didn't mind having
the caliper off center, remove the centering pin completely, and the
caliper would exert exactly the same leverage.
>
>
>>> Your argument of float does not answer my question: how does an
>>> arm with a 1:1 ratio from cable to pad, support a 200N pad force with
>>> 100N cable tension.
>> because one arm has a 2:1 ratio and the rim floats.
>
> That is not an answer. I'm not asking about the 2:1 arm, or the
> rim, I'm asking about a 1:1 lever which you claim can have 100N on one
> end, and 200N on the other.
but it can't. the moment the pads touch the rim, the rim transmits the
force from one side to the other and equilibrium results.
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| | |
Date: 11 Nov 2007 21:59:51
From: Luns Tee
Subject: Re: rear rim seems to rub
|
In article <G4idnZaT64HH1aranZ2dnUVZ_oesnZ2d@speakeasy.net >,
jim beam <spamvortex@bad.example.net > wrote:
>> How does the centering happen if not by transmitting a force
>> where the Y and C arms meet? Your neglecting this force is the heart
>> of why your conclusions are wrong.
>
>but luns, the force on the centering pin is simply against the spring.
>the y-arm can move independently. you could, if you didn't mind having
>the caliper off center, remove the centering pin completely, and the
>caliper would exert exactly the same leverage.
You can't remove the centering pin. It's not just loaded by the
spring tension, it's loaded by cable tension too.
>>>> Your argument of float does not answer my question: how does an
>>>> arm with a 1:1 ratio from cable to pad, support a 200N pad force with
>>>> 100N cable tension.
>>> because one arm has a 2:1 ratio and the rim floats.
>>
>> That is not an answer. I'm not asking about the 2:1 arm, or the
>> rim, I'm asking about a 1:1 lever which you claim can have 100N on one
>> end, and 200N on the other.
>
>but it can't. the moment the pads touch the rim, the rim transmits the
>force from one side to the other and equilibrium results.
If the ratio of the caliper as a whole is 2:1 as you say, the
force being transmitted across the rim is 200N. How is 100N on the cable
side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
-Luns
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| | | |
Date: 12 Nov 2007 04:55:54
From:
Subject: Re: rear rim seems to rub
|
Luns Tee writes:
>>> How does the centering happen if not by transmitting a force where
>>> the Y and C arms meet? Your neglecting this force is the heart of
>>> why your conclusions are wrong.
>> but luns, the force on the centering pin is simply against the
>> spring. the y-arm can move independently. you could, if you
>> didn't mind having the caliper off center, remove the centering pin
>> completely, and the caliper would exert exactly the same leverage.
> You can't remove the centering pin. It's not just loaded by the
> spring tension, it's loaded by cable tension too.
>>>>> Your argument of float does not answer my question: how does an
>>>>> arm with a 1:1 ratio from cable to pad, support a 200N pad force
>>>>> with 100N cable tension.
>>>> because one arm has a 2:1 ratio and the rim floats.
>>> That is not an answer. I'm not asking about the 2:1 arm, or the
>>> rim, I'm asking about a 1:1 lever which you claim can have 100N on
>>> one end, and 200N on the other.
>> but it can't. the moment the pads touch the rim, the rim transmits
>> the force from one side to the other and equilibrium results.
> If the ratio of the caliper as a whole is 2:1 as you say, the force
> being transmitted across the rim is 200N. How is 100N on the cable
> side of the Y arm, vs. 200N on the pad side of the Y arm an
> equilibrium?
Let me suggest once more that measuring the cable stroke vs. the
combined pad stroke is far more diagnostic than trying to unravel the
complex leverage of the two arms that are activated by different
leverage and have different centers of rotation
To do this, put a block between the hand lever and handlebar that
allows a fixed stroke. Measure cable movement at the brake caliper
and then measure the outside-to-outside distance change over the brake
pads for that fixed stroke. The rim does not enter into this at all
except that the stroke should not exceed limits that normally exist.
I think you'll get a different result that estimating what the caliper
lever lengths are. The hand lever is easily measured.
Jobst Brandt
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| | | | |
Date: 12 Nov 2007 08:57:09
From: Tim McNamara
Subject: Re: rear rim seems to rub
|
jobst.brandt@stanfordalumni.org wrote:
> Luns Tee writes:
>
>>>> How does the centering happen if not by transmitting a force
>>>> where the Y and C arms meet? Your neglecting this force is the
>>>> heart of why your conclusions are wrong.
>
>>> but luns, the force on the centering pin is simply against the
>>> spring. the y-arm can move independently. you could, if you
>>> didn't mind having the caliper off center, remove the centering
>>> pin completely, and the caliper would exert exactly the same
>>> leverage.
>
>> You can't remove the centering pin. It's not just loaded by the
>> spring tension, it's loaded by cable tension too.
>
>>>>>> Your argument of float does not answer my question: how
>>>>>> does an arm with a 1:1 ratio from cable to pad, support a
>>>>>> 200N pad force with 100N cable tension.
>
>>>>> because one arm has a 2:1 ratio and the rim floats.
>
>>>> That is not an answer. I'm not asking about the 2:1 arm, or
>>>> the rim, I'm asking about a 1:1 lever which you claim can have
>>>> 100N on one end, and 200N on the other.
>
>>> but it can't. the moment the pads touch the rim, the rim
>>> transmits the force from one side to the other and equilibrium
>>> results.
>
>> If the ratio of the caliper as a whole is 2:1 as you say, the force
>> being transmitted across the rim is 200N. How is 100N on the
>> cable side of the Y arm, vs. 200N on the pad side of the Y arm an
>> equilibrium?
>
> Let me suggest once more that measuring the cable stroke vs. the
> combined pad stroke is far more diagnostic than trying to unravel the
> complex leverage of the two arms that are activated by different
> leverage and have different centers of rotation
>
> To do this, put a block between the hand lever and handlebar that
> allows a fixed stroke. Measure cable movement at the brake caliper
> and then measure the outside-to-outside distance change over the
> brake pads for that fixed stroke. The rim does not enter into this
> at all except that the stroke should not exceed limits that normally
> exist.
>
> I think you'll get a different result that estimating what the
> caliper lever lengths are. The hand lever is easily measured.
Measurement of the behavior of the whole system makes the discussion too
simple for Usenet, Jobst. ;-)
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Date: 12 Nov 2007 05:31:40
From: Luns Tee
Subject: Re: rear rim seems to rub
|
In article <4737dcda$0$14078$742ec2ed@news.sonic.net >,
<jobst.brandt@stanfordalumni.org > wrote:
>Let me suggest once more that measuring the cable stroke vs. the
>combined pad stroke is far more diagnostic than trying to unravel the
>complex leverage of the two arms that are activated by different
>leverage and have different centers of rotation
>
>To do this, put a block between the hand lever and handlebar that
>allows a fixed stroke. Measure cable movement at the brake caliper
>and then measure the outside-to-outside distance change over the brake
>pads for that fixed stroke. The rim does not enter into this at all
>except that the stroke should not exceed limits that normally exist.
>
>I think you'll get a different result that estimating what the caliper
>lever lengths are. The hand lever is easily measured.
For a dual-pivot Shimano 105 caliper:
Open Closed
Pad spacing: 27.1mm 22.8mm
Cable length: 26.9mm 20.7mm
Pad spacing measured at the toe of the brake pads, cable length
is measured between the bottom of the adjuster to the top of the end
clamp. I did not measure hand lever throw
Mechanical advantage = (26.9-20.7)/(27.1-22.8) = 6.2/4.3 = 1.44
-Luns
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Date: 11 Nov 2007 21:42:30
From: jim beam
Subject: Re: rear rim seems to rub
|
Luns Tee wrote:
> In article <4737dcda$0$14078$742ec2ed@news.sonic.net>,
> <jobst.brandt@stanfordalumni.org> wrote:
>> Let me suggest once more that measuring the cable stroke vs. the
>> combined pad stroke is far more diagnostic than trying to unravel the
>> complex leverage of the two arms that are activated by different
>> leverage and have different centers of rotation
>>
>> To do this, put a block between the hand lever and handlebar that
>> allows a fixed stroke. Measure cable movement at the brake caliper
>> and then measure the outside-to-outside distance change over the brake
>> pads for that fixed stroke. The rim does not enter into this at all
>> except that the stroke should not exceed limits that normally exist.
>>
>> I think you'll get a different result that estimating what the caliper
>> lever lengths are. The hand lever is easily measured.
>
>
> For a dual-pivot Shimano 105 caliper:
>
> Open Closed
> Pad spacing: 27.1mm 22.8mm
> Cable length: 26.9mm 20.7mm
>
> Pad spacing measured at the toe of the brake pads, cable length
> is measured between the bottom of the adjuster to the top of the end
> clamp. I did not measure hand lever throw
>
> Mechanical advantage = (26.9-20.7)/(27.1-22.8) = 6.2/4.3 = 1.44
which doesn't account for rim float and equilibrium.
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| | | | | |
Date: 12 Nov 2007 05:40:18
From:
Subject: Re: rear rim seems to rub
|
Luns Tee writes:
>> Let me suggest once more that measuring the cable stroke vs. the
>> combined pad stroke is far more diagnostic than trying to unravel
>> the complex leverage of the two arms that are activated by
>> different leverage and have different centers of rotation
>> To do this, put a block between the hand lever and handlebar that
>> allows a fixed stroke. Measure cable movement at the brake caliper
>> and then measure the outside-to-outside distance change over the
>> brake pads for that fixed stroke. The rim does not enter into this
>> at all except that the stroke should not exceed limits that
>> normally exist.
>> I think you'll get a different result that estimating what the
>> caliper lever lengths are. The hand lever is easily measured.
> For a dual-pivot Shimano 105 caliper:
> Open Closed
> Pad spacing: 27.1mm 22.8mm
> Cable length: 26.9mm 20.7mm
> Pad spacing measured at the toe of the brake pads, cable length
> is measured between the bottom of the adjuster to the top of the end
> clamp. I did not measure hand lever throw
> Mechanical advantage = (26.9-20.7)/(27.1-22.8) = 6.2/4.3 = 1.44
Thanks. I didn't redo my measurements because I would have to take my
1:1 calipers off, mount the dual pivot caliper, install brake pads and
engage the brake cable to do someone else's homework. The linkage of
the dual; pivot caliper is not readily discernible and varies slightly
with adjustment of the position screw. For this reason and others the
stroke measurement works best.
Jobst Brandt
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| | | | | | |
Date: 11 Nov 2007 21:48:28
From: jim beam
Subject: Re: rear rim seems to rub
|
jobst.brandt@stanfordalumni.org wrote:
> Luns Tee writes:
>
>>> Let me suggest once more that measuring the cable stroke vs. the
>>> combined pad stroke is far more diagnostic than trying to unravel
>>> the complex leverage of the two arms that are activated by
>>> different leverage and have different centers of rotation
>
>>> To do this, put a block between the hand lever and handlebar that
>>> allows a fixed stroke. Measure cable movement at the brake caliper
>>> and then measure the outside-to-outside distance change over the
>>> brake pads for that fixed stroke. The rim does not enter into this
>>> at all except that the stroke should not exceed limits that
>>> normally exist.
>
>>> I think you'll get a different result that estimating what the
>>> caliper lever lengths are. The hand lever is easily measured.
>
>
>> For a dual-pivot Shimano 105 caliper:
>
>> Open Closed
>> Pad spacing: 27.1mm 22.8mm
>> Cable length: 26.9mm 20.7mm
>
>> Pad spacing measured at the toe of the brake pads, cable length
>> is measured between the bottom of the adjuster to the top of the end
>> clamp. I did not measure hand lever throw
>
>> Mechanical advantage = (26.9-20.7)/(27.1-22.8) = 6.2/4.3 = 1.44
>
> Thanks. I didn't redo my measurements because I would have to take my
> 1:1 calipers off, mount the dual pivot caliper, install brake pads and
> engage the brake cable to do someone else's homework. The linkage of
> the dual; pivot caliper is not readily discernible
eh???
> and varies slightly
> with adjustment of the position screw.
no it doesn't, the centering ratio remains the same.
> For this reason and others the
> stroke measurement works best.
no, it contains cosine errors.
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| | | | | | | |
Date: 12 Nov 2007 06:05:38
From:
Subject: Re: rear rim seems to rub
|
http://tinyurl.com/yqfryo writes:
>>>> Let me suggest once more that measuring the cable stroke vs. the
>>>> combined pad stroke is far more diagnostic than trying to unravel
>>>> the complex leverage of the two arms that are activated by
>>>> different leverage and have different centers of rotation
>>>> To do this, put a block between the hand lever and handlebar that
>>>> allows a fixed stroke. Measure cable movement at the brake caliper
>>>> and then measure the outside-to-outside distance change over the
>>>> brake pads for that fixed stroke. The rim does not enter into this
>>>> at all except that the stroke should not exceed limits that
>>>> normally exist.
>>>> I think you'll get a different result that estimating what the
>>>> caliper lever lengths are. The hand lever is easily measured.
>>> For a dual-pivot Shimano 105 caliper:
>>> Open Closed
>>> Pad spacing: 27.1mm 22.8mm
>>> Cable length: 26.9mm 20.7mm
>>> Pad spacing measured at the toe of the brake pads, cable length
>>> is measured between the bottom of the adjuster to the top of the end
>>> clamp. I did not measure hand lever throw
>>> Mechanical advantage = (26.9-20.7)/(27.1-22.8) = 6.2/4.3 = 1.44
>> Thanks. I didn't redo my measurements because I would have to take
>> my 1:1 calipers off, mount the dual pivot caliper, install brake
>> pads and engage the brake cable to do someone else's homework. The
>> linkage of the dual; pivot caliper is not readily discernible
> eh???
I see you are hard of hearing. This is the stereotype response of an
oldster who doesn't have his ear trumpet in place.
>> and varies slightly with adjustment of the position screw.
> no it doesn't, the centering ratio remains the same.
You keep mentioning rim float as though the rim were displaced by the
caliper. The purpose of the dual pivot is to assure that the caliper
operates about the fixed rim and is not closer on one side than the
other (to avoid pad drag). There is no rim float and it can
accomplish nothing.
>> For this reason and others the stroke measurement works best.
> no, it contains cosine errors.
You should review cosine error for angles +-5 degrees about zero. It
is less than 0.4%. So how does this make Luns' measurement less
accurate than your guesstimate of lever lengths? Besides, you have
your leverages confused. The leverage is the same on both sides or
the rim would deflect on the order of pad clearance.
Jobst Brandt
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Date: 13 Nov 2007 05:54:49
From: jim beam
Subject: Re: rear rim seems to rub
|
jobst.brandt@stanfordalumni.org wrote:
> http://tinyurl.com/yqfryo writes:
>
>>>>> Let me suggest once more that measuring the cable stroke vs. the
>>>>> combined pad stroke is far more diagnostic than trying to unravel
>>>>> the complex leverage of the two arms that are activated by
>>>>> different leverage and have different centers of rotation
>
>>>>> To do this, put a block between the hand lever and handlebar that
>>>>> allows a fixed stroke. Measure cable movement at the brake caliper
>>>>> and then measure the outside-to-outside distance change over the
>>>>> brake pads for that fixed stroke. The rim does not enter into this
>>>>> at all except that the stroke should not exceed limits that
>>>>> normally exist.
>
>>>>> I think you'll get a different result that estimating what the
>>>>> caliper lever lengths are. The hand lever is easily measured.
>
>>>> For a dual-pivot Shimano 105 caliper:
>
>>>> Open Closed
>>>> Pad spacing: 27.1mm 22.8mm
>>>> Cable length: 26.9mm 20.7mm
>
>>>> Pad spacing measured at the toe of the brake pads, cable length
>>>> is measured between the bottom of the adjuster to the top of the end
>>>> clamp. I did not measure hand lever throw
>
>>>> Mechanical advantage = (26.9-20.7)/(27.1-22.8) = 6.2/4.3 = 1.44
>
>>> Thanks. I didn't redo my measurements because I would have to take
>>> my 1:1 calipers off, mount the dual pivot caliper, install brake
>>> pads and engage the brake cable to do someone else's homework. The
>>> linkage of the dual; pivot caliper is not readily discernible
>
>> eh???
>
> I see you are hard of hearing. This is the stereotype response of an
> oldster who doesn't have his ear trumpet in place.
what an idiotic waste of electrons.
>
>>> and varies slightly with adjustment of the position screw.
>
>> no it doesn't, the centering ratio remains the same.
>
> You keep mentioning rim float as though the rim were displaced by the
> caliper. The purpose of the dual pivot is to assure that the caliper
> operates about the fixed rim and is not closer on one side than the
> other (to avoid pad drag). There is no rim float and it can
> accomplish nothing.
this is the problem with people that don't use the equipment, then want
to criticize - they make embarrassing mistakes. if you've ever used
dual pivot, and had it off center, first thing you'll note on
application is that the rim moves to fit the pad center, not the other
way around.
>
>>> For this reason and others the stroke measurement works best.
>
>> no, it contains cosine errors.
>
> You should review cosine error for angles +-5 degrees about zero. It
> is less than 0.4%. So how does this make Luns' measurement less
> accurate than your guesstimate of lever lengths? Besides, you have
> your leverages confused. The leverage is the same on both sides or
> the rim would deflect on the order of pad clearance.
no jobst, i do not have my leverage ratios confused. compound levers do
not "average" if the application point floats. and in this case, it does.
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| | | | |
Date: 11 Nov 2007 21:16:07
From: jim beam
Subject: Re: rear rim seems to rub
|
jobst.brandt@stanfordalumni.org wrote:
> Luns Tee writes:
>
>>>> How does the centering happen if not by transmitting a force where
>>>> the Y and C arms meet? Your neglecting this force is the heart of
>>>> why your conclusions are wrong.
>
>>> but luns, the force on the centering pin is simply against the
>>> spring. the y-arm can move independently. you could, if you
>>> didn't mind having the caliper off center, remove the centering pin
>>> completely, and the caliper would exert exactly the same leverage.
>
>> You can't remove the centering pin. It's not just loaded by the
>> spring tension, it's loaded by cable tension too.
>
>>>>>> Your argument of float does not answer my question: how does an
>>>>>> arm with a 1:1 ratio from cable to pad, support a 200N pad force
>>>>>> with 100N cable tension.
>
>>>>> because one arm has a 2:1 ratio and the rim floats.
>
>>>> That is not an answer. I'm not asking about the 2:1 arm, or the
>>>> rim, I'm asking about a 1:1 lever which you claim can have 100N on
>>>> one end, and 200N on the other.
>
>>> but it can't. the moment the pads touch the rim, the rim transmits
>>> the force from one side to the other and equilibrium results.
>
>> If the ratio of the caliper as a whole is 2:1 as you say, the force
>> being transmitted across the rim is 200N. How is 100N on the cable
>> side of the Y arm, vs. 200N on the pad side of the Y arm an
>> equilibrium?
>
> Let me suggest once more that measuring the cable stroke vs. the
> combined pad stroke is far more diagnostic than trying to unravel the
> complex leverage of the two arms that are activated by different
> leverage and have different centers of rotation
>
> To do this, put a block between the hand lever and handlebar that
> allows a fixed stroke. Measure cable movement at the brake caliper
> and then measure the outside-to-outside distance change over the brake
> pads for that fixed stroke. The rim does not enter into this at all
> except that the stroke should not exceed limits that normally exist.
>
> I think you'll get a different result that estimating what the caliper
> lever lengths are. The hand lever is easily measured.
that's a fudge - it involves the cosines. measure leverage ratios from
the caliper directly.
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| | | |
Date: 11 Nov 2007 20:14:53
From: jim beam
Subject: Re: rear rim seems to rub
|
Luns Tee wrote:
> In article <G4idnZaT64HH1aranZ2dnUVZ_oesnZ2d@speakeasy.net>,
> jim beam <spamvortex@bad.example.net> wrote:
>>> How does the centering happen if not by transmitting a force
>>> where the Y and C arms meet? Your neglecting this force is the heart
>>> of why your conclusions are wrong.
>> but luns, the force on the centering pin is simply against the spring.
>> the y-arm can move independently. you could, if you didn't mind having
>> the caliper off center, remove the centering pin completely, and the
>> caliper would exert exactly the same leverage.
>
> You can't remove the centering pin.
on shimano you can - it just unscrews.
> It's not just loaded by the
> spring tension, it's loaded by cable tension too.
no, it's just loaded by the spring. try it - you can move the y-arm
independently.
>
>
>>>>> Your argument of float does not answer my question: how does an
>>>>> arm with a 1:1 ratio from cable to pad, support a 200N pad force with
>>>>> 100N cable tension.
>>>> because one arm has a 2:1 ratio and the rim floats.
>>> That is not an answer. I'm not asking about the 2:1 arm, or the
>>> rim, I'm asking about a 1:1 lever which you claim can have 100N on one
>>> end, and 200N on the other.
>> but it can't. the moment the pads touch the rim, the rim transmits the
>> force from one side to the other and equilibrium results.
>
> If the ratio of the caliper as a whole is 2:1 as you say, the
> force being transmitted across the rim is 200N. How is 100N on the cable
> side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
"floating" of the rim. just like in the avid mechanical disk brake caliper.
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| | | | |
Date: 12 Nov 2007 04:57:08
From: Luns Tee
Subject: Re: rear rim seems to rub
|
In article <NbWdnWU_bsWjTqranZ2dnUVZ_tGonZ2d@speakeasy.net >,
jim beam <spamvortex@bad.example.net > wrote:
>Luns Tee wrote:
>> In article <G4idnZaT64HH1aranZ2dnUVZ_oesnZ2d@speakeasy.net>,
>> jim beam <spamvortex@bad.example.net> wrote:
>>>> How does the centering happen if not by transmitting a force
>>>> where the Y and C arms meet? Your neglecting this force is the heart
>>>> of why your conclusions are wrong.
>>> but luns, the force on the centering pin is simply against the spring.
>>> the y-arm can move independently. you could, if you didn't mind having
>>> the caliper off center, remove the centering pin completely, and the
>>> caliper would exert exactly the same leverage.
>>
>> You can't remove the centering pin.
>
>on shimano you can - it just unscrews.
What you implied though did not explicitly say is that the
caliper is free to swing laterally without any centering effect if the
pin is removed; my comment was directed at that.
The screw unscrews yes, but then the bottom of the Y arm where
the pin would have been protruding then rests against the C arm, and the
linkage between the arms is still there. Aside from the offset in
centering, everything still works the same as if the screw were there:
you can remove the screw, but you cannot remove the linkage that the
screw represents. As long as the linkage is there, the arms do not
move independently.
>> It's not just loaded by the
>> spring tension, it's loaded by cable tension too.
>
>no, it's just loaded by the spring. try it - you can move the y-arm
>independently.
Not when the cable is under tension.
>>>>>> Your argument of float does not answer my question: how does an
>>>>>> arm with a 1:1 ratio from cable to pad, support a 200N pad force with
>>>>>> 100N cable tension.
>>>>> because one arm has a 2:1 ratio and the rim floats.
>>>> That is not an answer. I'm not asking about the 2:1 arm, or the
>>>> rim, I'm asking about a 1:1 lever which you claim can have 100N on one
>>>> end, and 200N on the other.
>>> but it can't. the moment the pads touch the rim, the rim transmits the
>>> force from one side to the other and equilibrium results.
>>
>> If the ratio of the caliper as a whole is 2:1 as you say, the
>> force being transmitted across the rim is 200N. How is 100N on the cable
>> side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
>
>"floating" of the rim. just like in the avid mechanical disk brake caliper.
Floating only means that the supposed 200N from the C arm pad
is carried through to the Y arm pad, but the question is of how the Y
arm is able to press 200N against this - this is implicit in the
question I pose. Repeating part of the question is not an answer to
the question. You still have not addressed the question of how a 1:1
lever can have forces on it in a 2:1 ratio yet be in equilbrium.
If the Y arm does not see a force from the centering linkage as
you claim, then with a 100N cable tension, there is 100N at its pad,
while the C arm has 200N at its pad. The only way this can be is if the
rim can support 100N laterally, in which case the total of 300N pressing
on friction surfaces is an average of 150N on each side. With the 100N
cable tension, this is a mechanical advantage of 1.5.
However, as you say, the rim floats. With the C arm
outpowering the Y arm by 100N, the rim will want to move towards the Y
arm, however moving still does not change the mechanical advantage of
either arm, so even if after the rim moves a bit, it still sees 200N on
one side and 100N on the other. So the rim moves a bit more. The
forces still don't change, so the rim still wants to move.
Obviously, this can't go on indefinitely - what stops it from
going on indefinitely is the centering linkage between arms. Once it's
engaged, the adjusting screw on the Y arm is pressed upwards by the C
arm with enough force to provide an extra 50N at its brake pad. The
screw pressing down on the C arm reduces the force at its pad by 50N.
Both brake pads are brought to the 150N average of the force
that each arm's mechanical advantage on their own would dictate. The
mechanical advantage of the caliper is the average of the two arms'
mechanical advantage.
-Luns
|
| | | | | |
Date: 12 Nov 2007 05:28:16
From:
Subject: Re: rear rim seems to rub
|
Lungs Tee writes:
>>>>> How does the centering happen if not by transmitting a force
>>>>> where the Y and C arms meet? Your neglecting this force is the
>>>>> heart of why your conclusions are wrong.
>>>> but lune, the force on the centering pin is simply against the
>>>> spring. the y-arm can move independently. you could, if you
>>>> didn't mind having the caliper off center, remove the centering
>>>> pin completely, and the caliper would exert exactly the same
>>>> leverage.
>>> You can't remove the centering pin.
>> on shimano you can - it just unscrews.
> What you implied though did not explicitly say is that the caliper
> is free to swing laterally without any centering effect if the pin
> is removed; my comment was directed at that.
> The screw unscrews yes, but then the bottom of the Y arm where the
> pin would have been protruding then rests against the C arm, and the
> linkage between the arms is still there. Aside from the offset in
> centering, everything still works the same as if the screw were
> there: you can remove the screw, but you cannot remove the linkage
> that the screw represents. As long as the linkage is there, the
> arms do not move independently.
>>> It's not just loaded by the spring tension, it's loaded by cable
>>> tension too.
>> no, it's just loaded by the spring. try it - you can move the
>> y-arm independently.
> Not when the cable is under tension.
>>>>>>> Your argument of float does not answer my question: how does
>>>>>>> an arm with a 1:1 ratio from cable to pad, support a 200N pad
>>>>>>> force with 100N cable tension.
>>>>>> because one arm has a 2:1 ratio and the rim floats.
>>>>> That is not an answer. I'm not asking about the 2:1 arm, or the
>>>>> rim, I'm asking about a 1:1 lever which you claim can have 100N
>>>>> on one end, and 200N on the other.
>>>> but it can't. the moment the pads touch the rim, the rim
>>>> transmits the force from one side to the other and equilibrium
>>>> results.
>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>> force being transmitted across the rim is 200N. How is 100N on
>>> the cable side of the Y arm, vs. 200N on the pad side of the Y
>>> arm an equilibrium?
>> "floating" of the rim. just like in the avid mechanical disk brake
>> caliper.
> Floating only means that the supposed 200N from the C arm pad is
> carried through to the Y arm pad, but the question is of how the Y
> arm is able to press 200N against this - this is implicit in the
> question I pose. Repeating part of the question is not an answer to
> the question. You still have not addressed the question of how a
> 1:1 lever can have forces on it in a 2:1 ratio yet be in equilibrium.
> If the Y arm does not see a force from the centering linkage as you
> claim, then with a 100N cable tension, there is 100N at its pad,
> while the C arm has 200N at its pad. The only way this can be is if
> the rim can support 100N laterally, in which case the total of 300N
> pressing on friction surfaces is an average of 150N on each side.
> With the 100N cable tension, this is a mechanical advantage of 1.5.
> However, as you say, the rim floats. With the C arm out-powering
> the Y arm by 100N, the rim will want to move toward the Y arm,
> however moving still does not change the mechanical advantage of
> either arm, so even if after the rim moves a bit, it still sees 200N
> on one side and 100N on the other. So the rim moves a bit more.
> The forces still don't change, so the rim still wants to move.
> Obviously, this can't go on indefinitely - what stops it from going
> on indefinitely is the centering linkage between arms. Once it's
> engaged, the adjusting screw on the Y arm is pressed upward by the C
> arm with enough force to provide an extra 50N at its brake pad. The
> screw pressing down on the C arm reduces the force at its pad by
> 50N.
> Both brake pads are brought to the 150N average of the force that
> each arm's mechanical advantage on their own would dictate. The
> mechanical advantage of the caliper is the average of the two arms'
> mechanical advantage.
Dual pivot calipers cannot float, that being one of their weaknesses;
not being able to track a wobbling rim. The two arms of the caliper
are bound to articulate together equally at all times. Therefore the
scenario of the floating rim is meaningless. By pushing either pad
inward, notice mirror image motion of the opposite one.
Trying to measure effective caliper arm lengths is illusive. Measure
relative travel as I suggested. That's how I arrived at my ratios.
Jobst Brandt
|
| | | | | | |
Date: 11 Nov 2007 21:39:33
From: jim beam
Subject: Re: rear rim seems to rub
|
jobst.brandt@stanfordalumni.org wrote:
> Lungs Tee writes:
>
>>>>>> How does the centering happen if not by transmitting a force
>>>>>> where the Y and C arms meet? Your neglecting this force is the
>>>>>> heart of why your conclusions are wrong.
>
>>>>> but lune, the force on the centering pin is simply against the
>>>>> spring. the y-arm can move independently. you could, if you
>>>>> didn't mind having the caliper off center, remove the centering
>>>>> pin completely, and the caliper would exert exactly the same
>>>>> leverage.
>
>>>> You can't remove the centering pin.
>
>>> on shimano you can - it just unscrews.
>
>> What you implied though did not explicitly say is that the caliper
>> is free to swing laterally without any centering effect if the pin
>> is removed; my comment was directed at that.
>
>> The screw unscrews yes, but then the bottom of the Y arm where the
>> pin would have been protruding then rests against the C arm, and the
>> linkage between the arms is still there. Aside from the offset in
>> centering, everything still works the same as if the screw were
>> there: you can remove the screw, but you cannot remove the linkage
>> that the screw represents. As long as the linkage is there, the
>> arms do not move independently.
>
>>>> It's not just loaded by the spring tension, it's loaded by cable
>>>> tension too.
>
>>> no, it's just loaded by the spring. try it - you can move the
>>> y-arm independently.
>
>> Not when the cable is under tension.
>
>>>>>>>> Your argument of float does not answer my question: how does
>>>>>>>> an arm with a 1:1 ratio from cable to pad, support a 200N pad
>>>>>>>> force with 100N cable tension.
>
>>>>>>> because one arm has a 2:1 ratio and the rim floats.
>
>>>>>> That is not an answer. I'm not asking about the 2:1 arm, or the
>>>>>> rim, I'm asking about a 1:1 lever which you claim can have 100N
>>>>>> on one end, and 200N on the other.
>
>>>>> but it can't. the moment the pads touch the rim, the rim
>>>>> transmits the force from one side to the other and equilibrium
>>>>> results.
>
>>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>>> force being transmitted across the rim is 200N. How is 100N on
>>>> the cable side of the Y arm, vs. 200N on the pad side of the Y
>>>> arm an equilibrium?
>
>>> "floating" of the rim. just like in the avid mechanical disk brake
>>> caliper.
>
>> Floating only means that the supposed 200N from the C arm pad is
>> carried through to the Y arm pad, but the question is of how the Y
>> arm is able to press 200N against this - this is implicit in the
>> question I pose. Repeating part of the question is not an answer to
>> the question. You still have not addressed the question of how a
>> 1:1 lever can have forces on it in a 2:1 ratio yet be in equilibrium.
>
>> If the Y arm does not see a force from the centering linkage as you
>> claim, then with a 100N cable tension, there is 100N at its pad,
>> while the C arm has 200N at its pad. The only way this can be is if
>> the rim can support 100N laterally, in which case the total of 300N
>> pressing on friction surfaces is an average of 150N on each side.
>> With the 100N cable tension, this is a mechanical advantage of 1.5.
>
>> However, as you say, the rim floats. With the C arm out-powering
>> the Y arm by 100N, the rim will want to move toward the Y arm,
>> however moving still does not change the mechanical advantage of
>> either arm, so even if after the rim moves a bit, it still sees 200N
>> on one side and 100N on the other. So the rim moves a bit more.
>> The forces still don't change, so the rim still wants to move.
>
>> Obviously, this can't go on indefinitely - what stops it from going
>> on indefinitely is the centering linkage between arms. Once it's
>> engaged, the adjusting screw on the Y arm is pressed upward by the C
>> arm with enough force to provide an extra 50N at its brake pad. The
>> screw pressing down on the C arm reduces the force at its pad by
>> 50N.
>
>> Both brake pads are brought to the 150N average of the force that
>> each arm's mechanical advantage on their own would dictate. The
>> mechanical advantage of the caliper is the average of the two arms'
>> mechanical advantage.
>
> Dual pivot calipers cannot float, that being one of their weaknesses;
> not being able to track a wobbling rim. The two arms of the caliper
> are bound to articulate together equally at all times. Therefore the
> scenario of the floating rim is meaningless. By pushing either pad
> inward, notice mirror image motion of the opposite one.
but the rim floats!
>
> Trying to measure effective caliper arm lengths is illusive.
translation: "i missed something".
> Measure
> relative travel as I suggested. That's how I arrived at my ratios.
clearly.
|
| | | | | |
Date: 11 Nov 2007 21:14:10
From: jim beam
Subject: Re: rear rim seems to rub
|
Luns Tee wrote:
> In article <NbWdnWU_bsWjTqranZ2dnUVZ_tGonZ2d@speakeasy.net>,
> jim beam <spamvortex@bad.example.net> wrote:
>> Luns Tee wrote:
>>> In article <G4idnZaT64HH1aranZ2dnUVZ_oesnZ2d@speakeasy.net>,
>>> jim beam <spamvortex@bad.example.net> wrote:
>>>>> How does the centering happen if not by transmitting a force
>>>>> where the Y and C arms meet? Your neglecting this force is the heart
>>>>> of why your conclusions are wrong.
>>>> but luns, the force on the centering pin is simply against the spring.
>>>> the y-arm can move independently. you could, if you didn't mind having
>>>> the caliper off center, remove the centering pin completely, and the
>>>> caliper would exert exactly the same leverage.
>>> You can't remove the centering pin.
>> on shimano you can - it just unscrews.
>
> What you implied though did not explicitly say is that the
> caliper is free to swing laterally without any centering effect if the
> pin is removed; my comment was directed at that.
no, that's not what i implied or meant at all.
> The screw unscrews yes, but then the bottom of the Y arm where
> the pin would have been protruding then rests against the C arm, and the
> linkage between the arms is still there.
it could be completely cut away, and brake leverage would remain the same.
> Aside from the offset in
> centering, everything still works the same as if the screw were there:
> you can remove the screw, but you cannot remove the linkage that the
> screw represents. As long as the linkage is there, the arms do not
> move independently.
the y-arm can move independently of the c-arm. the force connection
between the two is simply from the return spring.
>
>>> It's not just loaded by the
>>> spring tension, it's loaded by cable tension too.
>> no, it's just loaded by the spring. try it - you can move the y-arm
>> independently.
>
> Not when the cable is under tension.
actually, yes it is - it's in the same direction as application and
against the spring.
>
>>>>>>> Your argument of float does not answer my question: how does an
>>>>>>> arm with a 1:1 ratio from cable to pad, support a 200N pad force with
>>>>>>> 100N cable tension.
>>>>>> because one arm has a 2:1 ratio and the rim floats.
>>>>> That is not an answer. I'm not asking about the 2:1 arm, or the
>>>>> rim, I'm asking about a 1:1 lever which you claim can have 100N on one
>>>>> end, and 200N on the other.
>>>> but it can't. the moment the pads touch the rim, the rim transmits the
>>>> force from one side to the other and equilibrium results.
>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>> force being transmitted across the rim is 200N. How is 100N on the cable
>>> side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
>> "floating" of the rim. just like in the avid mechanical disk brake caliper.
>
> Floating only means that the supposed 200N from the C arm pad
> is carried through to the Y arm pad, but the question is of how the Y
> arm is able to press 200N against this - this is implicit in the
> question I pose. Repeating part of the question is not an answer to
> the question. You still have not addressed the question of how a 1:1
> lever can have forces on it in a 2:1 ratio yet be in equilbrium.
no, reconsider the avid disk caliper i mention. one pad is completely
fixed, but braking force is applied equally from both pads because the
disk floats. rims do the same.
>
> If the Y arm does not see a force from the centering linkage as
> you claim, then with a 100N cable tension, there is 100N at its pad,
> while the C arm has 200N at its pad. The only way this can be is if the
> rim can support 100N laterally, in which case the total of 300N pressing
> on friction surfaces is an average of 150N on each side. With the 100N
> cable tension, this is a mechanical advantage of 1.5.
no, if the rim floats, the force on each side has to be in equilibrium.
and again, the force from the connection is simply spring force.
>
> However, as you say, the rim floats. With the C arm
> outpowering the Y arm by 100N,
and the result is that the force experienced by both pads is the same!
action and reaction! one arm could be completely fixed!
> the rim will want to move towards the Y
> arm, however moving still does not change the mechanical advantage of
> either arm, so even if after the rim moves a bit, it still sees 200N on
> one side and 100N on the other.
that's impossible if the rim floats!
> So the rim moves a bit more. The
> forces still don't change, so the rim still wants to move.
>
> Obviously, this can't go on indefinitely - what stops it from
> going on indefinitely is the centering linkage between arms.
no, that simply serves to make sure both pads arrive at the rim at about
the same time. again, i ask that you examine that linkage closely - it
is tiny and weak. it does not bear any braking force.
> Once it's
> engaged, the adjusting screw on the Y arm is pressed upwards by the C
> arm with enough force to provide an extra 50N at its brake pad. The
> screw pressing down on the C arm reduces the force at its pad by 50N.
that's not spring resistance!
> Both brake pads are brought to the 150N average of the force
> that each arm's mechanical advantage on their own would dictate. The
> mechanical advantage of the caliper is the average of the two arms'
> mechanical advantage.
no, one over-rides the other. if that wasn't the case, the avid disk
brake caliper wouldn't work.
|
| | | | | | |
Date: 12 Nov 2007 07:49:30
From: Luns Tee
Subject: Re: rear rim seems to rub
|
In article <oZWdnS6ivZi-fKranZ2dnUVZ_jCdnZ2d@speakeasy.net >,
jim beam <spamvortex@bad.example.net > wrote:
>>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>>> force being transmitted across the rim is 200N. How is 100N on the cable
>>>> side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
>>> "floating" of the rim. just like in the avid mechanical disk brake caliper.
>>
>> Floating only means that the supposed 200N from the C arm pad
>> is carried through to the Y arm pad, but the question is of how the Y
>> arm is able to press 200N against this - this is implicit in the
>> question I pose. Repeating part of the question is not an answer to
>> the question. You still have not addressed the question of how a 1:1
>> lever can have forces on it in a 2:1 ratio yet be in equilbrium.
>
>no, reconsider the avid disk caliper i mention. one pad is completely
>fixed, but braking force is applied equally from both pads because the
>disk floats. rims do the same.
The one-side-fixed caliper is not a valid analogy: a 1:1 lever
between the pad and cable clamp is not a fixed stop. If the Y arm were a
fixed stop, then it would not rotate on its pivot, and we're left with a
single-pivot brake. What is under discussion is dual-pivot brakes.
One more time: how do you propose that the Y arm with 1:1 ratio
between lever and pad supports 100N at the cable and 200N at the pad as
you propose? I've asked this several times now, but you have yet to
give an answer other than waving your hands about the floating rim. The
floating rim is not an answer - it only deals with how the 200N gets to
the pad, not how the lever is able to support it.
A 1:1 lever with 100N pushing on one side and 200N pushing on
the other will retreat away from the 200N load until something changes
to affect the imbalance. If the Y arm were to run into a fixed stop,
then what you've been claiming would hold.
However, there is no such stop on the caliper. The only other
thing available for the Y arm to support the imbalance is the centering
linkage, which communicates with the C arm.
-Luns
|
| | | | | | | |
Date: 13 Nov 2007 05:53:33
From: jim beam
Subject: Re: rear rim seems to rub
|
Luns Tee wrote:
> In article <oZWdnS6ivZi-fKranZ2dnUVZ_jCdnZ2d@speakeasy.net>,
> jim beam <spamvortex@bad.example.net> wrote:
>>>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>>>> force being transmitted across the rim is 200N. How is 100N on the cable
>>>>> side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
>>>> "floating" of the rim. just like in the avid mechanical disk brake caliper.
>>> Floating only means that the supposed 200N from the C arm pad
>>> is carried through to the Y arm pad, but the question is of how the Y
>>> arm is able to press 200N against this - this is implicit in the
>>> question I pose. Repeating part of the question is not an answer to
>>> the question. You still have not addressed the question of how a 1:1
>>> lever can have forces on it in a 2:1 ratio yet be in equilbrium.
>> no, reconsider the avid disk caliper i mention. one pad is completely
>> fixed, but braking force is applied equally from both pads because the
>> disk floats. rims do the same.
>
> The one-side-fixed caliper is not a valid analogy: a 1:1 lever
> between the pad and cable clamp is not a fixed stop. If the Y arm were a
> fixed stop, then it would not rotate on its pivot, and we're left with a
> single-pivot brake. What is under discussion is dual-pivot brakes.
but luns, with respect, if the y-arm is fixed, you have exactly the same
braking as with the avid disk brake.
>
> One more time: how do you propose that the Y arm with 1:1 ratio
> between lever and pad supports 100N at the cable and 200N at the pad as
> you propose? I've asked this several times now, but you have yet to
> give an answer other than waving your hands about the floating rim. The
> floating rim is not an answer - it only deals with how the 200N gets to
> the pad, not how the lever is able to support it.
disk brake!!! check it out.
>
> A 1:1 lever with 100N pushing on one side and 200N pushing on
> the other will retreat away from the 200N load until something changes
> to affect the imbalance. If the Y arm were to run into a fixed stop,
> then what you've been claiming would hold.
> However, there is no such stop on the caliper. The only other
> thing available for the Y arm to support the imbalance is the centering
> linkage, which communicates with the C arm.
>
disk brake. check it out.
|
| | | | | | | | |
Date: 15 Nov 2007 07:42:01
From: Luns Tee
Subject: Re: rear rim seems to rub
|
In article <GOCdnY7kbLrAMaTanZ2dnUVZ_jmdnZ2d@speakeasy.net >,
jim beam <spamvortex@bad.example.net > wrote:
>Luns Tee wrote:
>> In article <oZWdnS6ivZi-fKranZ2dnUVZ_jCdnZ2d@speakeasy.net>,
>> jim beam <spamvortex@bad.example.net> wrote:
>>>>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>>>>> force being transmitted across the rim is 200N. How is 100N on the cable
>>>>>> side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
>>>>> "floating" of the rim. just like in the avid mechanical disk brake caliper.
>>>> Floating only means that the supposed 200N from the C arm pad
>>>> is carried through to the Y arm pad, but the question is of how the Y
>>>> arm is able to press 200N against this - this is implicit in the
>>>> question I pose. Repeating part of the question is not an answer to
>>>> the question. You still have not addressed the question of how a 1:1
>>>> lever can have forces on it in a 2:1 ratio yet be in equilbrium.
>>> no, reconsider the avid disk caliper i mention. one pad is completely
>>> fixed, but braking force is applied equally from both pads because the
>>> disk floats. rims do the same.
>>
>> The one-side-fixed caliper is not a valid analogy: a 1:1 lever
>> between the pad and cable clamp is not a fixed stop. If the Y arm were a
>> fixed stop, then it would not rotate on its pivot, and we're left with a
>> single-pivot brake. What is under discussion is dual-pivot brakes.
>
>but luns, with respect, if the y-arm is fixed, you have exactly the same
>braking as with the avid disk brake.
IF the y-arm is fixed, then I agree with the avid brake as a
model. However, you yourself have claimed that the Y arm is free to
pivot, independently of the C arm at that. What makes the Y arm, that
is otherwise free to pivot, into a fixed stop?
-Luns
|
| | | | | | | | | |
Date: 15 Nov 2007 06:03:16
From: jim beam
Subject: Re: rear rim seems to rub
|
Luns Tee wrote:
> In article <GOCdnY7kbLrAMaTanZ2dnUVZ_jmdnZ2d@speakeasy.net>,
> jim beam <spamvortex@bad.example.net> wrote:
>> Luns Tee wrote:
>>> In article <oZWdnS6ivZi-fKranZ2dnUVZ_jCdnZ2d@speakeasy.net>,
>>> jim beam <spamvortex@bad.example.net> wrote:
>>>>>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>>>>>> force being transmitted across the rim is 200N. How is 100N on the cable
>>>>>>> side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
>>>>>> "floating" of the rim. just like in the avid mechanical disk brake caliper.
>>>>> Floating only means that the supposed 200N from the C arm pad
>>>>> is carried through to the Y arm pad, but the question is of how the Y
>>>>> arm is able to press 200N against this - this is implicit in the
>>>>> question I pose. Repeating part of the question is not an answer to
>>>>> the question. You still have not addressed the question of how a 1:1
>>>>> lever can have forces on it in a 2:1 ratio yet be in equilbrium.
>>>> no, reconsider the avid disk caliper i mention. one pad is completely
>>>> fixed, but braking force is applied equally from both pads because the
>>>> disk floats. rims do the same.
>>> The one-side-fixed caliper is not a valid analogy: a 1:1 lever
>>> between the pad and cable clamp is not a fixed stop. If the Y arm were a
>>> fixed stop, then it would not rotate on its pivot, and we're left with a
>>> single-pivot brake. What is under discussion is dual-pivot brakes.
>> but luns, with respect, if the y-arm is fixed, you have exactly the same
>> braking as with the avid disk brake.
>
> IF the y-arm is fixed, then I agree with the avid brake as a
> model. However, you yourself have claimed that the Y arm is free to
> pivot, independently of the C arm at that.
it can be compressed independently of the c-arm.
> What makes the Y arm, that
> is otherwise free to pivot, into a fixed stop?
application of pressure from the brake cable. clearly, it's not
/actually/ fixed by the cable, but it is relative to the c-arm, hence
the leverage ratio.
|
| | | | | | | | | | |
Date: 18 Nov 2007 07:27:14
From: Luns Tee
Subject: Re: rear rim seems to rub
|
In article <vaidncGliJ07zKHanZ2dnUVZ_tyknZ2d@speakeasy.net >,
jim beam <spamvortex@bad.example.net > wrote:
>Luns Tee wrote:
>> In article <GOCdnY7kbLrAMaTanZ2dnUVZ_jmdnZ2d@speakeasy.net>,
>> jim beam <spamvortex@bad.example.net> wrote:
>>> Luns Tee wrote:
>>>> In article <oZWdnS6ivZi-fKranZ2dnUVZ_jCdnZ2d@speakeasy.net>,
>>>> jim beam <spamvortex@bad.example.net> wrote:
>>>>>>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>>>>>>> force being transmitted across the rim is 200N. How is 100N on the cable
>>>>>>>> side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
>>>>>>> "floating" of the rim. just like in the avid mechanical disk brake caliper.
>>>>>> Floating only means that the supposed 200N from the C arm pad
>>>>>> is carried through to the Y arm pad, but the question is of how the Y
>>>>>> arm is able to press 200N against this - this is implicit in the
>>>>>> question I pose. Repeating part of the question is not an answer to
>>>>>> the question. You still have not addressed the question of how a 1:1
>>>>>> lever can have forces on it in a 2:1 ratio yet be in equilbrium.
>>>>> no, reconsider the avid disk caliper i mention. one pad is completely
>>>>> fixed, but braking force is applied equally from both pads because the
>>>>> disk floats. rims do the same.
>>>> The one-side-fixed caliper is not a valid analogy: a 1:1 lever
>>>> between the pad and cable clamp is not a fixed stop. If the Y arm were a
>>>> fixed stop, then it would not rotate on its pivot, and we're left with a
>>>> single-pivot brake. What is under discussion is dual-pivot brakes.
>>> but luns, with respect, if the y-arm is fixed, you have exactly the same
>>> braking as with the avid disk brake.
>>
>> IF the y-arm is fixed, then I agree with the avid brake as a
>> model. However, you yourself have claimed that the Y arm is free to
>> pivot, independently of the C arm at that.
>
>it can be compressed independently of the c-arm.
>
>
>> What makes the Y arm, that
>> is otherwise free to pivot, into a fixed stop?
>
>application of pressure from the brake cable.
That is NOT a fixed stop. A freely pivoting 1:1 lever transmits
force from the pad through to force at the cable in a 1:1 ratio. So I
ask you one more time, with 100N of cable tension, if things are as
you say, how does 200N at the pads constitute an equilibrium?
-Luns
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Date: 18 Nov 2007 19:17:42
From: jim beam
Subject: Re: rear rim seems to rub
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Luns Tee wrote:
> In article <vaidncGliJ07zKHanZ2dnUVZ_tyknZ2d@speakeasy.net>,
> jim beam <spamvortex@bad.example.net> wrote:
>> Luns Tee wrote:
>>> In article <GOCdnY7kbLrAMaTanZ2dnUVZ_jmdnZ2d@speakeasy.net>,
>>> jim beam <spamvortex@bad.example.net> wrote:
>>>> Luns Tee wrote:
>>>>> In article <oZWdnS6ivZi-fKranZ2dnUVZ_jCdnZ2d@speakeasy.net>,
>>>>> jim beam <spamvortex@bad.example.net> wrote:
>>>>>>>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>>>>>>>> force being transmitted across the rim is 200N. How is 100N on the cable
>>>>>>>>> side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
>>>>>>>> "floating" of the rim. just like in the avid mechanical disk brake caliper.
>>>>>>> Floating only means that the supposed 200N from the C arm pad
>>>>>>> is carried through to the Y arm pad, but the question is of how the Y
>>>>>>> arm is able to press 200N against this - this is implicit in the
>>>>>>> question I pose. Repeating part of the question is not an answer to
>>>>>>> the question. You still have not addressed the question of how a 1:1
>>>>>>> lever can have forces on it in a 2:1 ratio yet be in equilbrium.
>>>>>> no, reconsider the avid disk caliper i mention. one pad is completely
>>>>>> fixed, but braking force is applied equally from both pads because the
>>>>>> disk floats. rims do the same.
>>>>> The one-side-fixed caliper is not a valid analogy: a 1:1 lever
>>>>> between the pad and cable clamp is not a fixed stop. If the Y arm were a
>>>>> fixed stop, then it would not rotate on its pivot, and we're left with a
>>>>> single-pivot brake. What is under discussion is dual-pivot brakes.
>>>> but luns, with respect, if the y-arm is fixed, you have exactly the same
>>>> braking as with the avid disk brake.
>>> IF the y-arm is fixed, then I agree with the avid brake as a
>>> model. However, you yourself have claimed that the Y arm is free to
>>> pivot, independently of the C arm at that.
>> it can be compressed independently of the c-arm.
>>
>>
>>> What makes the Y arm, that
>>> is otherwise free to pivot, into a fixed stop?
>> application of pressure from the brake cable.
>
> That is NOT a fixed stop.
it is relative to the rim. hence equilibrium is established.
> A freely pivoting 1:1 lever transmits
> force from the pad through to force at the cable in a 1:1 ratio. So I
> ask you one more time, with 100N of cable tension, if things are as
> you say, how does 200N at the pads constitute an equilibrium?
see above. re-read the posts of myself and joe riel - repetition is
getting boring.
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Date: 19 Nov 2007 04:11:23
From: Luns Tee
Subject: Re: rear rim seems to rub
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In article <ArudnakJd_XLndzanZ2dnUVZ_t3inZ2d@speakeasy.net >,
jim beam <spamvortex@bad.example.net > wrote:
>Luns Tee wrote:
>> In article <vaidncGliJ07zKHanZ2dnUVZ_tyknZ2d@speakeasy.net>,
>> jim beam <spamvortex@bad.example.net> wrote:
>>> Luns Tee wrote:
>>>> In article <GOCdnY7kbLrAMaTanZ2dnUVZ_jmdnZ2d@speakeasy.net>,
>>>> jim beam <spamvortex@bad.example.net> wrote:
>>>>> Luns Tee wrote:
>>>>>> In article <oZWdnS6ivZi-fKranZ2dnUVZ_jCdnZ2d@speakeasy.net>,
>>>>>> jim beam <spamvortex@bad.example.net> wrote:
>>>>>>>>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>>>>>>>>> force being transmitted across the rim is 200N. How is 100N on the cable
>>>>>>>>>> side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
>>>>>>>>> "floating" of the rim. just like in the avid mechanical disk brake caliper.
>>>>>>>> Floating only means that the supposed 200N from the C arm pad
>>>>>>>> is carried through to the Y arm pad, but the question is of how the Y
>>>>>>>> arm is able to press 200N against this - this is implicit in the
>>>>>>>> question I pose. Repeating part of the question is not an answer to
>>>>>>>> the question. You still have not addressed the question of how a 1:1
>>>>>>>> lever can have forces on it in a 2:1 ratio yet be in equilbrium.
>>>>>>> no, reconsider the avid disk caliper i mention. one pad is completely
>>>>>>> fixed, but braking force is applied equally from both pads because the
>>>>>>> disk floats. rims do the same.
>>>>>> The one-side-fixed caliper is not a valid analogy: a 1:1 lever
>>>>>> between the pad and cable clamp is not a fixed stop. If the Y arm were a
>>>>>> fixed stop, then it would not rotate on its pivot, and we're left with a
>>>>>> single-pivot brake. What is under discussion is dual-pivot brakes.
>>>>> but luns, with respect, if the y-arm is fixed, you have exactly the same
>>>>> braking as with the avid disk brake.
>>>> IF the y-arm is fixed, then I agree with the avid brake as a
>>>> model. However, you yourself have claimed that the Y arm is free to
>>>> pivot, independently of the C arm at that.
>>> it can be compressed independently of the c-arm.
>>>
>>>
>>>> What makes the Y arm, that
>>>> is otherwise free to pivot, into a fixed stop?
>>> application of pressure from the brake cable.
>>
>> That is NOT a fixed stop.
>
>it is relative to the rim. hence equilibrium is established.
>> A freely pivoting 1:1 lever transmits
>> force from the pad through to force at the cable in a 1:1 ratio. So I
>> ask you one more time, with 100N of cable tension, if things are as
>> you say, how does 200N at the pads constitute an equilibrium?
>
>see above. re-read the posts of myself and joe riel - repetition is
>getting boring.
Yes, it is getting boring, however I repeat my question because
despite having been asked it over half a dozen times, you have yet
to give any sort of answer that is consistent with the fundamentals
of mechanics. A freely pivoting 1:1 lever has forces on its ends
in a 1:1 ratio, but you seem to believe that it can support a 2:1
ratio instead. If you actually had a consistent picture of how the
calipier works, you could tell us what forces each arm experiences,
and also show that these forces agree with the fundamentals of
mechanics. Instead, you just offer a non-statement using the word
'equilibrium' as though it were synonymous with 'abracadabra'.
So far as Joe Riel's posts, I don't see how anything he's said
supports your assertions at all, nor do I imagine he appreciates your
trying to claim that they do, but I will let him speak for himself.
Believe what you want - at this point, I believe it's clear
to everybody else that you do not present a consistent story with
your claim of a 2:1 caliper ratio, nor of the centering linkage being
uninvolved.
-Luns
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Date: 18 Nov 2007 20:37:05
From: jim beam
Subject: Re: rear rim seems to rub
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Luns Tee wrote:
> In article <ArudnakJd_XLndzanZ2dnUVZ_t3inZ2d@speakeasy.net>,
> jim beam <spamvortex@bad.example.net> wrote:
>> Luns Tee wrote:
>>> In article <vaidncGliJ07zKHanZ2dnUVZ_tyknZ2d@speakeasy.net>,
>>> jim beam <spamvortex@bad.example.net> wrote:
>>>> Luns Tee wrote:
>>>>> In article <GOCdnY7kbLrAMaTanZ2dnUVZ_jmdnZ2d@speakeasy.net>,
>>>>> jim beam <spamvortex@bad.example.net> wrote:
>>>>>> Luns Tee wrote:
>>>>>>> In article <oZWdnS6ivZi-fKranZ2dnUVZ_jCdnZ2d@speakeasy.net>,
>>>>>>> jim beam <spamvortex@bad.example.net> wrote:
>>>>>>>>>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>>>>>>>>>> force being transmitted across the rim is 200N. How is 100N on the cable
>>>>>>>>>>> side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
>>>>>>>>>> "floating" of the rim. just like in the avid mechanical disk brake caliper.
>>>>>>>>> Floating only means that the supposed 200N from the C arm pad
>>>>>>>>> is carried through to the Y arm pad, but the question is of how the Y
>>>>>>>>> arm is able to press 200N against this - this is implicit in the
>>>>>>>>> question I pose. Repeating part of the question is not an answer to
>>>>>>>>> the question. You still have not addressed the question of how a 1:1
>>>>>>>>> lever can have forces on it in a 2:1 ratio yet be in equilbrium.
>>>>>>>> no, reconsider the avid disk caliper i mention. one pad is completely
>>>>>>>> fixed, but braking force is applied equally from both pads because the
>>>>>>>> disk floats. rims do the same.
>>>>>>> The one-side-fixed caliper is not a valid analogy: a 1:1 lever
>>>>>>> between the pad and cable clamp is not a fixed stop. If the Y arm were a
>>>>>>> fixed stop, then it would not rotate on its pivot, and we're left with a
>>>>>>> single-pivot brake. What is under discussion is dual-pivot brakes.
>>>>>> but luns, with respect, if the y-arm is fixed, you have exactly the same
>>>>>> braking as with the avid disk brake.
>>>>> IF the y-arm is fixed, then I agree with the avid brake as a
>>>>> model. However, you yourself have claimed that the Y arm is free to
>>>>> pivot, independently of the C arm at that.
>>>> it can be compressed independently of the c-arm.
>>>>
>>>>
>>>>> What makes the Y arm, that
>>>>> is otherwise free to pivot, into a fixed stop?
>>>> application of pressure from the brake cable.
>>> That is NOT a fixed stop.
>> it is relative to the rim. hence equilibrium is established.
>
>>> A freely pivoting 1:1 lever transmits
>>> force from the pad through to force at the cable in a 1:1 ratio. So I
>>> ask you one more time, with 100N of cable tension, if things are as
>>> you say, how does 200N at the pads constitute an equilibrium?
>> see above. re-read the posts of myself and joe riel - repetition is
>> getting boring.
>
> Yes, it is getting boring, however I repeat my question because
> despite having been asked it over half a dozen times, you have yet
> to give any sort of answer that is consistent with the fundamentals
> of mechanics. A freely pivoting 1:1 lever has forces on its ends
> in a 1:1 ratio, but you seem to believe that it can support a 2:1
> ratio instead.
it's locked against the rim. it can therefore support the 2:1.
> If you actually had a consistent picture of how the
> calipier works, you could tell us what forces each arm experiences,
> and also show that these forces agree with the fundamentals of
> mechanics. Instead, you just offer a non-statement using the word
> 'equilibrium' as though it were synonymous with 'abracadabra'.
i guess it would seem like magic if you're not following the above.
>
> So far as Joe Riel's posts, I don't see how anything he's said
> supports your assertions at all, nor do I imagine he appreciates your
> trying to claim that they do, but I will let him speak for himself.
why not ask yourself why he bothered to raise the point?
>
> Believe what you want - at this point, I believe it's clear
> to everybody else that you do not present a consistent story with
> your claim of a 2:1 caliper ratio, nor of the centering linkage being
> uninvolved.
dude, with respect, if the rim floats, and it does, it doesn't matter
/what/ the 1:1 arm does, provided it doesn't actually back off. it's
just like a floating automotive brake caliper. joe's posts are
absolutely relevant - you need to re-read them.
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Date: 19 Nov 2007 06:25:58
From: Luns Tee
Subject: Re: rear rim seems to rub
|
In article <r8ednVBcc51sj9zanZ2dnUVZ_j-dnZ2d@speakeasy.net >,
jim beam <spamvortex@bad.example.net > wrote:
>> Yes, it is getting boring, however I repeat my question because
>> despite having been asked it over half a dozen times, you have yet
>> to give any sort of answer that is consistent with the fundamentals
>> of mechanics. A freely pivoting 1:1 lever has forces on its ends
>> in a 1:1 ratio, but you seem to believe that it can support a 2:1
>> ratio instead.
>
>it's locked against the rim. it can therefore support the 2:1.
By your reasoning, if I place a 10kg weight on one side of a
beam balance (1:1 lever), and a 20kg weight on the other, the two are
able to balance in equilbrium because the scale is locked against 20kg
weight. Doesn't work that way.
-Luns
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Date: 18 Nov 2007 02:18:48
From: Tom Sherman
Subject: Re: rear rim seems to rub
|
Luns Tee wrote:
> In article <vaidncGliJ07zKHanZ2dnUVZ_tyknZ2d@speakeasy.net>,
> jim beam <spamvortex@bad.example.net> wrote:
>> Luns Tee wrote:
>>> In article <GOCdnY7kbLrAMaTanZ2dnUVZ_jmdnZ2d@speakeasy.net>,
>>> jim beam <spamvortex@bad.example.net> wrote:
>>>> Luns Tee wrote:
>>>>> In article <oZWdnS6ivZi-fKranZ2dnUVZ_jCdnZ2d@speakeasy.net>,
>>>>> jim beam <spamvortex@bad.example.net> wrote:
>>>>>>>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>>>>>>>> force being transmitted across the rim is 200N. How is 100N on the cable
>>>>>>>>> side of the Y arm, vs. 200N on the pad side of the Y arm an equilibrium?
>>>>>>>> "floating" of the rim. just like in the avid mechanical disk brake caliper.
>>>>>>> Floating only means that the supposed 200N from the C arm pad
>>>>>>> is carried through to the Y arm pad, but the question is of how the Y
>>>>>>> arm is able to press 200N against this - this is implicit in the
>>>>>>> question I pose. Repeating part of the question is not an answer to
>>>>>>> the question. You still have not addressed the question of how a 1:1
>>>>>>> lever can have forces on it in a 2:1 ratio yet be in equilbrium.
>>>>>> no, reconsider the avid disk caliper i mention. one pad is completely
>>>>>> fixed, but braking force is applied equally from both pads because the
>>>>>> disk floats. rims do the same.
>>>>> The one-side-fixed caliper is not a valid analogy: a 1:1 lever
>>>>> between the pad and cable clamp is not a fixed stop. If the Y arm were a
>>>>> fixed stop, then it would not rotate on its pivot, and we're left with a
>>>>> single-pivot brake. What is under discussion is dual-pivot brakes.
>>>> but luns, with respect, if the y-arm is fixed, you have exactly the same
>>>> braking as with the avid disk brake.
>>> IF the y-arm is fixed, then I agree with the avid brake as a
>>> model. However, you yourself have claimed that the Y arm is free to
>>> pivot, independently of the C arm at that.
>> it can be compressed independently of the c-arm.
>>
>>
>>> What makes the Y arm, that
>>> is otherwise free to pivot, into a fixed stop?
>> application of pressure from the brake cable.
>
> That is NOT a fixed stop. A freely pivoting 1:1 lever transmits
> force from the pad through to force at the cable in a 1:1 ratio. So I
> ask you one more time, with 100N of cable tension, if things are as
> you say, how does 200N at the pads constitute an equilibrium?
Things work differently in the "beamian" world?
--
Tom Sherman - Holstein-Friesland Bovinia
"the grinning buddy bear carries a fork." - g.d.
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Date: 18 Nov 2007 19:21:56
From: jim beam
Subject: Re: rear rim seems to rub
|
Tom Sherman wrote:
> Luns Tee wrote:
>> In article <vaidncGliJ07zKHanZ2dnUVZ_tyknZ2d@speakeasy.net>,
>> jim beam <spamvortex@bad.example.net> wrote:
>>> Luns Tee wrote:
>>>> In article <GOCdnY7kbLrAMaTanZ2dnUVZ_jmdnZ2d@speakeasy.net>,
>>>> jim beam <spamvortex@bad.example.net> wrote:
>>>>> Luns Tee wrote:
>>>>>> In article <oZWdnS6ivZi-fKranZ2dnUVZ_jCdnZ2d@speakeasy.net>,
>>>>>> jim beam <spamvortex@bad.example.net> wrote:
>>>>>>>>>> If the ratio of the caliper as a whole is 2:1 as you say, the
>>>>>>>>>> force being transmitted across the rim is 200N. How is 100N on
>>>>>>>>>> the cable
>>>>>>>>>> side of the Y arm, vs. 200N on the pad side of the Y arm an
>>>>>>>>>> equilibrium?
>>>>>>>>> "floating" of the rim. just like in the avid mechanical disk
>>>>>>>>> brake caliper.
>>>>>>>> Floating only means that the supposed 200N from the C arm pad
>>>>>>>> is carried through to the Y arm pad, but the question is of how
>>>>>>>> the Y
>>>>>>>> arm is able to press 200N against this - this is implicit in the
>>>>>>>> question I pose. Repeating part of the question is not an answer to
>>>>>>>> the question. You still have not addressed the question of how
>>>>>>>> a 1:1
>>>>>>>> lever can have forces on it in a 2:1 ratio yet be in equilbrium.
>>>>>>> no, reconsider the avid disk caliper i mention. one pad is
>>>>>>> completely fixed, but braking force is applied equally from both
>>>>>>> pads because the disk floats. rims do the same.
>>>>>> The one-side-fixed caliper is not a valid analogy: a 1:1 lever
>>>>>> between the pad and cable clamp is not a fixed stop. If the Y arm
>>>>>> were a
>>>>>> fixed stop, then it would not rotate on its pivot, and we're left
>>>>>> with a
>>>>>> single-pivot brake. What is under discussion is dual-pivot brakes.
>>>>> but luns, with respect, if the y-arm is fixed, you have exactly the
>>>>> same
>>>>> braking as with the avid disk brake.
>>>> IF the y-arm is fixed, then I agree with the avid brake as a
>>>> model. However, you yourself have claimed that the Y arm is free to
>>>> pivot, independently of the C arm at that.
>>> it can be compressed independently of the c-arm.
>>>
>>>
>>>> What makes the Y arm, that
>>>> is otherwise free to pivot, into a fixed stop?
>>> application of pressure from the brake cable.
>>
>> That is NOT a fixed stop. A freely pivoting 1:1 lever transmits
>> force from the pad through to force at the cable in a 1:1 ratio. So I
>> ask you one more time, with 100N of cable tension, if things are as
>> you say, how does 200N at the pads constitute an equilibrium?
>
> Things work differently in the "beamian" world?
>
whiny lightweight.
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