Bike adjustments

On Friday, 13 December 2019 10:22:31 UTC-5, jbeattie wrote:
On Friday, December 13, 2019 at 4:16:43 AM UTC-8, Duane wrote:
wrote:
On Friday, December 13, 2019 at 6:20:03 AM UTC+1, jbeattie wrote:
On Thursday, December 12, 2019 at 8:07:35 PM UTC-8, James wrote:
On 12/12/19 3:02 pm, Ralph Barone wrote:
James wrote:


With disc brakes you would only need to flip the axle quick release and
take the wheel out, and not need to fiddle with the brakes at all..


Yeah, but if I unintentionally squeeze my brake levers on my canti equipped
bike with no wheel installed, it’s a pretty easy recovery.


It's a non-issue with mechanical disc brakes too.

You might be thinking of hydraulics? I'm not so keen on them, like I'm
not so keen on electronic gear shifting.


Its a 20 second fix, assuming one squeeze is enough to prevent
re-installation of the wheel. I prefer hydraulic to cable discs for
braking feel and the fact that the pads are self-adjusting, but cables
are fine, too - except on my CAADX commuter because of the long cable
run in housing caused a lot of drag, and the return springs on the BB5
were weak. I definitely prefer hydro discs on that bike.

-- Jay Beattie.

I bought a cross bike after disks brakes became available for them (never
wanted a crossbike with canti lever brakes; they are really crap for that
kind of riding). First cable disks. Never liked them on my cross bike.. I
had more issues with them than I have with my current hydraulic disks..
Never had any issues with these hydraulic brakes in almost six years now.
My 'biggest problem' is breaking in the pads which is the same for cable
discs. I don't understand why people prefer cable discs on off road bikes
for off road riding with a lot of mud. Glad I'm not hydrau phobic.

Like you said you have to squeeze really hard to get into trouble
reinstalling you wheel and then it is an 20 seconds fix with your tire
lever. It is not something that happens just by accident on a regular basis.

Lou


Isn’t there a spacer or clip or something to keep the pads in place when
taking off the wheel? I haven’t tried disc brakes but friends that put
their bikes on my roof rack seem to have something like that. Doesn’t seem
like a big issue.

It isn't a big issue. The usual problem with disc bikes and roof racks are through axles. Your friend apparently had an adapter or a non-through axle bike.

-- Jay Beattie.

The warning I read about a few years ago was that if you took the wheel off a disc brake bike after using the brakes a lot and you accidentaly squeezed the brake lever that the pads(iirc) could then fuse together.

Cheers

John B. writes:

On Thu, 12 Dec 2019 23:16:41 -0500, Joy Beeson
wrote:

On Wed, 11 Dec 2019 06:50:44 +0700, John B.
wrote:

Didn't I hear you exclaiming the merits of your slide rule?

While cleaning his room, my spouse found a stash of slide rules
including, I believe, mine. After some thought, I put them into the
glass-front bookcase with the history books.

If I recall correctly, multiplication was quite easy, and I could
probably still do it. Our physicics tests were to "slide rule
accuracy", that is, you needed only to show enough digits to prove
that you'd done the right things to the right numbers. (Mine was a
cheap bamboo rule and didn't give useful answers, except for
sanity-testing.)

One short cut I took proved that laziness can pay. We were given a
four-place table that we were supposed to interpolate to five places.
Instead of practicing interpolation as I was supposed to do, I bought
a five-place table. And shortly after I graduated, interpolation went
out of style.

Interpolation has never been more in fashion, mostly done wholesale by
machines. Tables are everywhere, but in silicon, not on paper.

Nowadays I use my calculators only for money and miles per hour. The
first two or three digits don't cut it any more. (Well, on mph, two
digits are plenty!)

At one point I was in charge of calculating percentages on the Wing's
fleet of aircraft. This was before the days of electric calculators
and I thought a slip stick would work so bought one only to find that
they wouldn't indicate to the last decimal point, or perhaps more
accurately, that I couldn't read them to the last decimal point. And
believe me that as far as the Wing Commander is concerned 30.5 and
30.59 are different numbers when reporting to higher headquarters
(30.59 can be rounded to 31 :-)

I remember a story that at Wright-Patterson AFB (one of the
development bases) they had a 10 foot long slide rule in a temperature
controlled room for doing really accurate calculations I don't know
whether that is true, however it does sound possible.

That sounds like a tall tale to me. Even back in the thirties heavy
computations were done digitally by rooms full of "computers", many of
them mathematically inclined women, using ten key adding machines and
passing slips of paper to one another. Richard Feynman describes this
kind of work during the Manhattan project.

One of the more useful make work projects of the depression in the US
was the recalculation of a slew of mathematical tables. Eventually the
results became Abramowitz and Stegun, _Handbook of Mathematical
Functions_, which was an everyday reference back when I first
encountered it.

There were other shortcut computation methods before calculators and
computers became so cheap. Graphs for actual lookup were popular. You
could buy graph paper at a technical book store with half a dozen
variations on the scales: log-log, semi-log, probability ...

Building nomograms was a useful art, and using them a basic skill. In
the chem lab, functions were integrated by cutting them out in filter
paper and weighing them on the analytical balance. Every field had its
set of graphical methods for calculation, from the really graphical,
like lofting plans for ships or planes, to the more mathematical, like
designing distillation columns.

John B. wrote:
:On Thu, 12 Dec 2019 23:16:41 -0500, Joy Beeson
wrote:

:On Wed, 11 Dec 2019 06:50:44 +0700, John B.
wrote:
:
: Didn't I hear you exclaiming the merits of your slide rule?
:
:While cleaning his room, my spouse found a stash of slide rules
:including, I believe, mine. After some thought, I put them into the
:glass-front bookcase with the history books.
:
:If I recall correctly, multiplication was quite easy, and I could
:probably still do it. Our physicics tests were to "slide rule
:accuracy", that is, you needed only to show enough digits to prove
:that you'd done the right things to the right numbers. (Mine was a
:cheap bamboo rule and didn't give useful answers, except for
:sanity-testing.)
:
:One short cut I took proved that laziness can pay. We were given a
:four-place table that we were supposed to interpolate to five places.
:Instead of practicing interpolation as I was supposed to do, I bought
:a five-place table. And shortly after I graduated, interpolation went
:out of style.
:
:Nowadays I use my calculators only for money and miles per hour. The
:first two or three digits don't cut it any more. (Well, on mph, two
:digits are plenty!)

:At one point I was in charge of calculating percentages on the Wing's
:fleet of aircraft. This was before the days of electric calculators
:and I thought a slip stick would work so bought one only to find that
:they wouldn't indicate to the last decimal point, or perhaps more
:accurately, that I couldn't read them to the last decimal point. And
:believe me that as far as the Wing Commander is concerned 30.5 and
:30.59 are different numbers when reporting to higher headquarters
30.59 can be rounded to 31 :-)

:I remember a story that at Wright-Patterson AFB (one of the
:development bases) they had a 10 foot long slide rule in a temperature
:controlled room for doing really accurate calculations I don't know
:whether that is true, however it does sound possible.

10 foot slide rules existed, but they were for teaching. One of my
college physics profs had one in his office. He had to open the
office door to use it. Yard or two long rules did exist, for
precision, and had built in magnification.


--
sig 58

On 12/13/2019 11:01 AM, Radey Shouman wrote:
John B. writes:


I remember a story that at Wright-Patterson AFB (one of the
development bases) they had a 10 foot long slide rule in a temperature
controlled room for doing really accurate calculations I don't know
whether that is true, however it does sound possible.

That sounds like a tall tale to me.

ISTR hearing of oversized slide rules being used for additional
accuracy. But I never heard they were in a temperature controlled room,
and I doubt they would need that. The relevant parts would expand or
contract at the same rate.

Even back in the thirties heavy
computations were done digitally by rooms full of "computers", many of
them mathematically inclined women, using ten key adding machines and
passing slips of paper to one another. Richard Feynman describes this
kind of work during the Manhattan project.

The excellent movie _Hidden Figures_ covered that in great detail.

There were other shortcut computation methods before calculators and
computers became so cheap. Graphs for actual lookup were popular. You
could buy graph paper at a technical book store with half a dozen
variations on the scales: log-log, semi-log, probability ...

:-) And I still have - somewhere! - my stock of at least a dozen types
of graph paper. (Not that a retiree has much use for them...) But I
did appreciate an unusual Christmas gift: Graph paper sticky notes.

Building nomograms was a useful art, and using them a basic skill. In
the chem lab, functions were integrated by cutting them out in filter
paper and weighing them on the analytical balance. Every field had its
set of graphical methods for calculation, from the really graphical,
like lofting plans for ships or planes, to the more mathematical, like
designing distillation columns.

I wonder how many people here have used a planimeter?
https://en.wikipedia.org/wiki/Planimeter
An analog one with a vernier scale?


--
- Frank Krygowski

On 12/13/2019 1:22 AM, John B. wrote:
On Thu, 12 Dec 2019 23:54:58 -0500, Joy Beeson
wrote:

On Thu, 12 Dec 2019 13:56:07 +0700, John B.
wrote:

http://wlweather.net/PAGESEW/BLOG1XVI/PATIEN6h.JPG


Errr... That isn't a photo of anything that my wife sewed.... In the
early years of our marriage she apprenticed herself to a "Ladies
Tailor" (to translate freely) and has been making her own clothes for
40 years or more.

It's a picture of something that I sewed very badly.

Hence, he'd be better off recruiting her than me.

Ah... sorry about that :-)

Apparently you need a bit of practice :-(

When we lived on the boat I used to convince my wife that I needed
help making a new canopy for the boat so she'd sit on the dock - with
my sail making sewing machine - and sew 40 foot seams :-)

This summer, some friends and I were invited to sail on The Dreamer out
of Erie Harbor. It's a beautiful old vessel, built in 1929 and restored
by its current owner, who happens to be a sailmaker.

https://www.youtube.com/watch?v=PMKSLEtdjLQ

Here's an idea of what it looked like when he took possession:
http://coletech.net/coltrek/Dreamer.htm

We played tunes for a couple hours while the owner cruised us around the
harbor area. It was a lovely, smooth ride on a very beautiful boat.

--
- Frank Krygowski

On 12/13/2019 7:22 AM, jbeattie wrote:

snip

It isn't a big issue. The usual problem with disc bikes and roof racks are through axles. Your friend apparently had an adapter or a non-through axle bike.

In any case you really want a rooftop rack where both wheels stay on the
bicycle. They are less damaging to the bicycle, are less trouble, and
take less time. Jobst went into this years ago
https://groups.google.com/d/msg/rec.bicycles.tech/5YvLUBuRgsM/YiVJtyRYAKoJ.

On 12/13/2019 8:34 AM, Frank Krygowski wrote:
On 12/13/2019 11:01 AM, Radey Shouman wrote:
John B. writes:


I remember a story that at Wright-Patterson AFB (one of the
development bases) they had a 10 foot long slide rule in a temperature
controlled room for doing really accurate calculations I don't know
whether that is true, however it does sound possible.

That sounds like a tall tale to me.

ISTR hearing of oversized slide rules being used for additional
accuracy. But I never heard they were in a temperature controlled room,
and I doubt they would need that. The relevant parts would expand or
contract at the same rate.

Even back in the thirties heavy
computations were done digitally by rooms full of "computers", many of
them mathematically inclined women, using ten key adding machines and
passing slips of paper to one another.Â* Richard Feynman describes this
kind of work during the Manhattan project.

The excellent movie _Hidden Figures_ covered that in great detail.

There were other shortcut computation methods before calculators and
computers became so cheap.Â* Graphs for actual lookup were popular.Â* You
could buy graph paper at a technical book store with half a dozen
variations on the scales: log-log, semi-log, probability ...

:-) And I still have - somewhere! - my stock of at least a dozen types
of graph paper. (Not that a retiree has much use for them...)Â*Â* But I
did appreciate an unusual Christmas gift: Graph paper sticky notes.

Building nomograms was a useful art, and using them a basic skill.Â* In
the chem lab, functions were integrated by cutting them out in filter
paper and weighing them on the analytical balance.Â* Every field had its
set of graphical methods for calculation, from the really graphical,
like lofting plans for ships or planes, to the more mathematical, like
designing distillation columns.

I wonder how many people here have used a planimeter?
https://en.wikipedia.org/wiki/Planimeter
An analog one with a vernier scale?

I've used a planimeter, but I think it was just for demonstration in a
teaching situation. It was a nice "Made in West Germany" model - which
attests to both its quality and its age. As an undergrad I had to do an
exercise deriving the theoretical basis for a planimeter's operation,
but I never saw one until years later, when it was essentially obsolete.

During my teaching career, I was "in charge" of the department's
historical artifacts - this means I was the only person who didn't want
to throw them out - so I hoarded the slide rules, including a 6' one
(for teaching, as David pointed out), the planimeter, and a host of
other "pedagogical tools."

Mark J.

On 12/13/2019 2:14 PM, Mark J. wrote:
On 12/13/2019 8:34 AM, Frank Krygowski wrote:
On 12/13/2019 11:01 AM, Radey Shouman wrote:
John B. writes:


I remember a story that at Wright-Patterson AFB (one of the
development bases) they had a 10 foot long slide rule in a temperature
controlled room for doing really accurate calculations I don't know
whether that is true, however it does sound possible.

That sounds like a tall tale to me.

ISTR hearing of oversized slide rules being used for additional
accuracy. But I never heard they were in a temperature controlled
room, and I doubt they would need that. The relevant parts would
expand or contract at the same rate.

Even back in the thirties heavy
computations were done digitally by rooms full of "computers", many of
them mathematically inclined women, using ten key adding machines and
passing slips of paper to one another.Â* Richard Feynman describes this
kind of work during the Manhattan project.

The excellent movie _Hidden Figures_ covered that in great detail.

There were other shortcut computation methods before calculators and
computers became so cheap.Â* Graphs for actual lookup were popular.Â* You
could buy graph paper at a technical book store with half a dozen
variations on the scales: log-log, semi-log, probability ...

:-) And I still have - somewhere! - my stock of at least a dozen types
of graph paper. (Not that a retiree has much use for them...)Â*Â* But I
did appreciate an unusual Christmas gift: Graph paper sticky notes.

Building nomograms was a useful art, and using them a basic skill.Â* In
the chem lab, functions were integrated by cutting them out in filter
paper and weighing them on the analytical balance.Â* Every field had its
set of graphical methods for calculation, from the really graphical,
like lofting plans for ships or planes, to the more mathematical, like
designing distillation columns.

I wonder how many people here have used a planimeter?
https://en.wikipedia.org/wiki/Planimeter
An analog one with a vernier scale?

I've used a planimeter, but I think it was just for demonstration in a
teaching situation.Â* It was a nice "Made in West Germany" model - which
attests to both its quality and its age.Â* As an undergrad I had to do an
exercise deriving the theoretical basis for a planimeter's operation,
but I never saw one until years later, when it was essentially obsolete.

During my teaching career, I was "in charge" of the department's
historical artifacts - this means I was the only person who didn't want
to throw them out - so I hoarded the slide rules, including a 6' one
(for teaching, as David pointed out), the planimeter, and a host of
other "pedagogical tools."

I remember being in France and happening across a small museum of
antique scientific instruments. So many were beautifully made, big
things of polished wood, brass and nickel. They looked like things out
of a steampunk movie set.

At one point in time, our school had an auction of its old laboratory
equipment. I lusted over a recording barometer driven by clockwork,
probably three feet high, a sort of glass cylinder with lovely wood and
a visible brass mechanism inside. But our house is too tiny to display
such a thing. And of course, these days the information is available on
a phone.

--
- Frank Krygowski

On 12/13/2019 1:14 PM, Mark J. wrote:
On 12/13/2019 8:34 AM, Frank Krygowski wrote:
On 12/13/2019 11:01 AM, Radey Shouman wrote:
John B. writes:


I remember a story that at Wright-Patterson AFB (one of the
development bases) they had a 10 foot long slide rule in
a temperature
controlled room for doing really accurate calculations
I don't know
whether that is true, however it does sound possible.

That sounds like a tall tale to me.

ISTR hearing of oversized slide rules being used for
additional accuracy. But I never heard they were in a
temperature controlled room, and I doubt they would need
that. The relevant parts would expand or contract at the
same rate.

Even back in the thirties heavy
computations were done digitally by rooms full of
"computers", many of
them mathematically inclined women, using ten key adding
machines and
passing slips of paper to one another. Richard Feynman
describes this
kind of work during the Manhattan project.

The excellent movie _Hidden Figures_ covered that in great
detail.

There were other shortcut computation methods before
calculators and
computers became so cheap. Graphs for actual lookup
were popular. You
could buy graph paper at a technical book store with half
a dozen
variations on the scales: log-log, semi-log, probability ...

:-) And I still have - somewhere! - my stock of at least a
dozen types of graph paper. (Not that a retiree has much
use for them...)Â Â But I did appreciate an unusual
Christmas gift: Graph paper sticky notes.

Building nomograms was a useful art, and using them a
basic skill. In
the chem lab, functions were integrated by cutting them
out in filter
paper and weighing them on the analytical balance.Â
Every field had its
set of graphical methods for calculation, from the really
graphical,
like lofting plans for ships or planes, to the more
mathematical, like
designing distillation columns.

I wonder how many people here have used a planimeter?
https://en.wikipedia.org/wiki/Planimeter
An analog one with a vernier scale?

I've used a planimeter, but I think it was just for
demonstration in a teaching situation. It was a nice "Made
in West Germany" model - which attests to both its quality
and its age. As an undergrad I had to do an exercise
deriving the theoretical basis for a planimeter's operation,
but I never saw one until years later, when it was
essentially obsolete.

During my teaching career, I was "in charge" of the
department's historical artifacts - this means I was the
only person who didn't want to throw them out - so I hoarded
the slide rules, including a 6' one (for teaching, as David
pointed out), the planimeter, and a host of other
"pedagogical tools."

Mark J.

"pedagogical tools."

The Good Sisters needed only an 18 inch wooden ruler to make
their point. Very effective too.


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

Mark J. wrote:
:On 12/13/2019 8:34 AM, Frank Krygowski wrote:
: On 12/13/2019 11:01 AM, Radey Shouman wrote:
: John B. writes:
:
:
: I remember a story that at Wright-Patterson AFB (one of the
: development bases) they had a 10 foot long slide rule in a temperature
: controlled room for doing really accurate calculations I don't know
: whether that is true, however it does sound possible.
:
: That sounds like a tall tale to me.
:
: ISTR hearing of oversized slide rules being used for additional
: accuracy. But I never heard they were in a temperature controlled room,
: and I doubt they would need that. The relevant parts would expand or
: contract at the same rate.
:
: Even back in the thirties heavy
: computations were done digitally by rooms full of "computers", many of
: them mathematically inclined women, using ten key adding machines and
: passing slips of paper to one another.Â* Richard Feynman describes this
: kind of work during the Manhattan project.
:
: The excellent movie _Hidden Figures_ covered that in great detail.
:
: There were other shortcut computation methods before calculators and
: computers became so cheap.Â* Graphs for actual lookup were popular.Â* You
: could buy graph paper at a technical book store with half a dozen
: variations on the scales: log-log, semi-log, probability ...
:
: :-) And I still have - somewhere! - my stock of at least a dozen types
: of graph paper. (Not that a retiree has much use for them...)Â*Â* But I
: did appreciate an unusual Christmas gift: Graph paper sticky notes.
:
: Building nomograms was a useful art, and using them a basic skill.Â* In
: the chem lab, functions were integrated by cutting them out in filter
: paper and weighing them on the analytical balance.Â* Every field had its
: set of graphical methods for calculation, from the really graphical,
: like lofting plans for ships or planes, to the more mathematical, like
: designing distillation columns.
:
: I wonder how many people here have used a planimeter?
: https://en.wikipedia.org/wiki/Planimeter
: An analog one with a vernier scale?

:I've used a planimeter, but I think it was just for demonstration in a
:teaching situation. It was a nice "Made in West Germany" model - which
:attests to both its quality and its age. As an undergrad I had to do an
:exercise deriving the theoretical basis for a planimeter's operation,
:but I never saw one until years later, when it was essentially obsolete.

I've used one in the last decade. Except it wasn't the sort of
mechanical device you're thinking of it. it was a rather large pen
thing, that you pushed a button, and then traced your object of
interest. After you were done you pushed the button (or maybe another
one). it then told you the perimeter and area of the shape you'd
traced, both the atual values, but also according to the scale you'd
told it. It belonged to an interior designer, she used it to make
material estimates from drawings done at the client's site. In the
office the cad software did all that for her/ I think ti stored the
data so you could import the traced shapes into the cad system later.

--
There's nothing sadder than an ontologist without an ontogenesis.
-- some guy with a beard