How critical is road bike tire pressure max?

On Monday, April 23, 2018 at 7:07:32 AM UTC-7, Frank Krygowski wrote:
On 4/23/2018 2:00 AM, John B. wrote:
On Sun, 22 Apr 2018 06:53:29 -0700, Joerg
wrote:

Pressure gauge? A seasoned cyclist should be able to gauge the tire
pressure with a thunb.

That sounds like an old experienced cyclist, but can you tell the
difference between 65 psi and, say 70 psi?

Years ago, our club used to run a family oriented picnic and bike tour
of the local metropark. The picnic featured several bike-oriented games.
One was to deflate your tire, then pump it up to the target pressure you
chose, without the use of a gage. As I recall, there were guys who got
within a couple percent of their target.

I can't tell 10psi, particularly between tires with different casings and sizes.

-- Jay Beattie.

On 23/04/2018 10:14 AM, jbeattie wrote:
On Monday, April 23, 2018 at 7:07:32 AM UTC-7, Frank Krygowski wrote:
On 4/23/2018 2:00 AM, John B. wrote:
On Sun, 22 Apr 2018 06:53:29 -0700, Joerg
wrote:

Pressure gauge? A seasoned cyclist should be able to gauge the tire
pressure with a thunb.

That sounds like an old experienced cyclist, but can you tell the
difference between 65 psi and, say 70 psi?

Years ago, our club used to run a family oriented picnic and bike tour
of the local metropark. The picnic featured several bike-oriented games.
One was to deflate your tire, then pump it up to the target pressure you
chose, without the use of a gage. As I recall, there were guys who got
within a couple percent of their target.

I can't tell 10psi, particularly between tires with different casings and sizes.


Maybe that's Joerg's issue with pinch flats...

On 2018-04-22 23:00, John B. wrote:
On Sun, 22 Apr 2018 06:53:29 -0700, Joerg
wrote:

On 2018-04-20 17:46, John B. wrote:
On Fri, 20 Apr 2018 10:25:59 -0700 (PDT), jbeattie
wrote:

On Thursday, April 19, 2018 at 10:45:47 AM UTC-7, Joerg wrote:
On 2018-04-18 18:16, Andre Jute wrote:
On Wednesday, April 18, 2018 at 6:02:49 PM UTC+1, Joerg wrote:
Just received some 25mm Vee Rubber road tires and it says
7bar 100psi max on the side. That's a bit low for my taste.

The Zafiro I have on there now says 100psi min and 130psi max
which is more up my alley.

By how much can a low max rating be exceeded? I like
100-115psi on my road bike in back. On the front I won't
exceed the max because a blow-out would be nasty and that
carries less weight anyhow.

-- Regards, Joerg

http://www.analogconsultants.com/

Is this some new California fad, riding offroad on narrow
rubber? Whatever for? BTW, I have no problem with low- or
zero-tread tyres because I ride mainly on tarmac, even in the
narrowest lanes, but surely a mudplugger wants considerable
mechanical grip.


No fad but road bikes out here must cope with road sections that
are either gravel or dirt. Part of life.


There's a good reason not to blow up tyres over the max
recommendation: It can get pretty nasty and expensive when
overinflated tyres blow the rim apart. It is well worth reading
Andy Blance, the designer of Sheldon's beloved Thorn bike, on
tyre inflation: see page 36 at
http://www.sjscycles.com/thornpdf/th...a_brochure.pdf


It's a 30+ MB file and their server seems to be on an old dial-up
line.


I was a convert to comfortable suspension and inflation
regimes already in my motor-racing days, and achieved the same
results the same way in cycling: see
http://thorncyclesforum.co.uk/index....16360#msg16360


(which is an extended version of a reply I first made on RBT to a
query by Pete Cresswell) and read on in the ensuing very
well-informed engineering discussion about ways of determining
the optimum tyre inflation.

In fact, there are all kinds of really good reasons for
inflating bicycle tyres to the lowest you can get away with
short of snake bites.


Right, and then you get a pinch flat or snake bite which is
often unfixable in the field. All it takes is one pothole. No
thanks.


Do you not carry a tube? You can squeeze one in next to the
heart-lung machine, rope, winch and iron rail segment used for
pounding in chain-pins with found fence nails. There should be
room in your pannier somewhere.

-- Jay Beattie.

But unless your nickname is Mighty Lung Larry, you also need to
carry a tire pump and then the pressure becomes a problem so you need
to carry a pressure gauge....


Unless you are in the hills weght doesn't matter much. Also, my Topeak
Pocket Rocket pump is small and doesn't weigh much. It is a lot better
than CO2 cartridges that many cyclists then carelessly leave laying
around on the ground.

Pressure gauge? A seasoned cyclist should be able to gauge the tire
pressure with a thunb.

That sounds like an old experienced cyclist, but can you tell the
difference between 65 psi and, say 70 psi?


Not necessary. What's necessary is to be able to tell when it is too far
below 100psi, say 80psi, and I can do that.



Just one problem after another..... Take the car?


For comparable health benefits it would need to be muscle-powered.

http://thenewswheel.com/wp-content/t...=90&w=660&zc=1

If you look into the matter you find that bicycling is certainly
better then sitting on the couch watching Oprah but that is about it.
Even marching at the standard rate (116 beats a minute with a 30 inch
pace) is a better exercise, ...


That's what a former colleague also though. Until his right hip wore out.


... both as a weight bearing activity and for
the heart-lung machine and if you get really frisky and try any of the
elite army unit "tads" then you are talking about 12 miles in 3 hours
carrying 32 Kg. in the U.S. Army, while the Romans, in ancient times,
did 35 km. in 5 hours carrying 20 kg.


Having served I am (painfully) aware of that. However, we were in our
20's, not close to retirement like now.

BTW, the US Army has switched to the metric system for distances many
moons ago.

--
Regards, Joerg

http://www.analogconsultants.com/

On Mon, 23 Apr 2018 09:36:00 -0700, Joerg
wrote:

On 2018-04-22 23:00, John B. wrote:
On Sun, 22 Apr 2018 06:53:29 -0700, Joerg
wrote:

On 2018-04-20 17:46, John B. wrote:
On Fri, 20 Apr 2018 10:25:59 -0700 (PDT), jbeattie
wrote:

On Thursday, April 19, 2018 at 10:45:47 AM UTC-7, Joerg wrote:
On 2018-04-18 18:16, Andre Jute wrote:
On Wednesday, April 18, 2018 at 6:02:49 PM UTC+1, Joerg wrote:
Just received some 25mm Vee Rubber road tires and it says
7bar 100psi max on the side. That's a bit low for my taste.

The Zafiro I have on there now says 100psi min and 130psi max
which is more up my alley.

By how much can a low max rating be exceeded? I like
100-115psi on my road bike in back. On the front I won't
exceed the max because a blow-out would be nasty and that
carries less weight anyhow.

-- Regards, Joerg

http://www.analogconsultants.com/

Is this some new California fad, riding offroad on narrow
rubber? Whatever for? BTW, I have no problem with low- or
zero-tread tyres because I ride mainly on tarmac, even in the
narrowest lanes, but surely a mudplugger wants considerable
mechanical grip.


No fad but road bikes out here must cope with road sections that
are either gravel or dirt. Part of life.


There's a good reason not to blow up tyres over the max
recommendation: It can get pretty nasty and expensive when
overinflated tyres blow the rim apart. It is well worth reading
Andy Blance, the designer of Sheldon's beloved Thorn bike, on
tyre inflation: see page 36 at
http://www.sjscycles.com/thornpdf/th...a_brochure.pdf


It's a 30+ MB file and their server seems to be on an old dial-up
line.


I was a convert to comfortable suspension and inflation
regimes already in my motor-racing days, and achieved the same
results the same way in cycling: see
http://thorncyclesforum.co.uk/index....16360#msg16360


(which is an extended version of a reply I first made on RBT to a
query by Pete Cresswell) and read on in the ensuing very
well-informed engineering discussion about ways of determining
the optimum tyre inflation.

In fact, there are all kinds of really good reasons for
inflating bicycle tyres to the lowest you can get away with
short of snake bites.


Right, and then you get a pinch flat or snake bite which is
often unfixable in the field. All it takes is one pothole. No
thanks.


Do you not carry a tube? You can squeeze one in next to the
heart-lung machine, rope, winch and iron rail segment used for
pounding in chain-pins with found fence nails. There should be
room in your pannier somewhere.

-- Jay Beattie.

But unless your nickname is Mighty Lung Larry, you also need to
carry a tire pump and then the pressure becomes a problem so you need
to carry a pressure gauge....


Unless you are in the hills weght doesn't matter much. Also, my Topeak
Pocket Rocket pump is small and doesn't weigh much. It is a lot better
than CO2 cartridges that many cyclists then carelessly leave laying
around on the ground.

Pressure gauge? A seasoned cyclist should be able to gauge the tire
pressure with a thunb.

That sounds like an old experienced cyclist, but can you tell the
difference between 65 psi and, say 70 psi?


Not necessary. What's necessary is to be able to tell when it is too far
below 100psi, say 80psi, and I can do that.



Just one problem after another..... Take the car?


For comparable health benefits it would need to be muscle-powered.

http://thenewswheel.com/wp-content/t...=90&w=660&zc=1

If you look into the matter you find that bicycling is certainly
better then sitting on the couch watching Oprah but that is about it.
Even marching at the standard rate (116 beats a minute with a 30 inch
pace) is a better exercise, ...


That's what a former colleague also though. Until his right hip wore out.


... both as a weight bearing activity and for
the heart-lung machine and if you get really frisky and try any of the
elite army unit "tads" then you are talking about 12 miles in 3 hours
carrying 32 Kg. in the U.S. Army, while the Romans, in ancient times,
did 35 km. in 5 hours carrying 20 kg.


Having served I am (painfully) aware of that. However, we were in our
20's, not close to retirement like now.


I'm older then you and I can still walk. Exercise, like any other
physical activity, must take into account the age and physical
condition of the individual.

If you read what I wrote, and understood it, I mentioned the "Tabs" as
something that elite troops might do. Not Joe Dobbs, average soldier.

BTW, the US Army has switched to the metric system for distances many
moons ago.

Who cares? Any measuring system works for those that understand the
system. 1 inch and 25.4mm are the same distance.
--
Cheers,

John B.

On Mon, 23 Apr 2018 08:01:13 -0500, AMuzi wrote:

On 4/23/2018 1:00 AM, John B. wrote:
On Sun, 22 Apr 2018 06:53:29 -0700, Joerg
wrote:

On 2018-04-20 17:46, John B. wrote:
On Fri, 20 Apr 2018 10:25:59 -0700 (PDT), jbeattie
wrote:

On Thursday, April 19, 2018 at 10:45:47 AM UTC-7, Joerg wrote:
On 2018-04-18 18:16, Andre Jute wrote:
On Wednesday, April 18, 2018 at 6:02:49 PM UTC+1, Joerg wrote:
Just received some 25mm Vee Rubber road tires and it says
7bar 100psi max on the side. That's a bit low for my taste.

The Zafiro I have on there now says 100psi min and 130psi max
which is more up my alley.

By how much can a low max rating be exceeded? I like
100-115psi on my road bike in back. On the front I won't
exceed the max because a blow-out would be nasty and that
carries less weight anyhow.

-- Regards, Joerg

http://www.analogconsultants.com/

Is this some new California fad, riding offroad on narrow
rubber? Whatever for? BTW, I have no problem with low- or
zero-tread tyres because I ride mainly on tarmac, even in the
narrowest lanes, but surely a mudplugger wants considerable
mechanical grip.


No fad but road bikes out here must cope with road sections that
are either gravel or dirt. Part of life.


There's a good reason not to blow up tyres over the max
recommendation: It can get pretty nasty and expensive when
overinflated tyres blow the rim apart. It is well worth reading
Andy Blance, the designer of Sheldon's beloved Thorn bike, on
tyre inflation: see page 36 at
http://www.sjscycles.com/thornpdf/th...a_brochure.pdf


It's a 30+ MB file and their server seems to be on an old dial-up
line.


I was a convert to comfortable suspension and inflation
regimes already in my motor-racing days, and achieved the same
results the same way in cycling: see
http://thorncyclesforum.co.uk/index....16360#msg16360


(which is an extended version of a reply I first made on RBT to a
query by Pete Cresswell) and read on in the ensuing very
well-informed engineering discussion about ways of determining
the optimum tyre inflation.

In fact, there are all kinds of really good reasons for
inflating bicycle tyres to the lowest you can get away with
short of snake bites.


Right, and then you get a pinch flat or snake bite which is
often unfixable in the field. All it takes is one pothole. No
thanks.


Do you not carry a tube? You can squeeze one in next to the
heart-lung machine, rope, winch and iron rail segment used for
pounding in chain-pins with found fence nails. There should be
room in your pannier somewhere.

-- Jay Beattie.

But unless your nickname is Mighty Lung Larry, you also need to
carry a tire pump and then the pressure becomes a problem so you need
to carry a pressure gauge....


Unless you are in the hills weght doesn't matter much. Also, my Topeak
Pocket Rocket pump is small and doesn't weigh much. It is a lot better
than CO2 cartridges that many cyclists then carelessly leave laying
around on the ground.

Pressure gauge? A seasoned cyclist should be able to gauge the tire
pressure with a thunb.

That sounds like an old experienced cyclist, but can you tell the
difference between 65 psi and, say 70 psi?



Just one problem after another..... Take the car?


For comparable health benefits it would need to be muscle-powered.

http://thenewswheel.com/wp-content/t...=90&w=660&zc=1

If you look into the matter you find that bicycling is certainly
better then sitting on the couch watching Oprah but that is about it.
Even marching at the standard rate (116 beats a minute with a 30 inch
pace) is a better exercise, both as a weight bearing activity and for
the heart-lung machine and if you get really frisky and try any of the
elite army unit "tads" then you are talking about 12 miles in 3 hours
carrying 32 Kg. in the U.S. Army, while the Romans, in ancient times,
did 35 km. in 5 hours carrying 20 kg.


Sometimes but not every day. Gaius Iulius notes that those
'hard march' events were rare. Sun Tzu explains the downside
in depth.

Marching at the "standard rate" was the normal way that troops were
moved from place to place and was, back in the day, done on a daily
basis.

What the British call "Tabs" were considerably more strenuous as it
was essentially marching at a somewhat faster cadence carrying
substantial weight.

The Roman Legions apparently marched for about 2/3rds of a day
carrying their gear and weapons - a Century did have several mule
carts assigned for carrying tents and other gear - and then built a
camp before "falling out" for the night. According to Caesar's reports
from Gaul this went on for days at a time.
--
Cheers,

John B.

On Mon, 23 Apr 2018 10:07:29 -0400, Frank Krygowski
wrote:

On 4/23/2018 2:00 AM, John B. wrote:
On Sun, 22 Apr 2018 06:53:29 -0700, Joerg
wrote:

Pressure gauge? A seasoned cyclist should be able to gauge the tire
pressure with a thunb.

That sounds like an old experienced cyclist, but can you tell the
difference between 65 psi and, say 70 psi?

Years ago, our club used to run a family oriented picnic and bike tour
of the local metropark. The picnic featured several bike-oriented games.
One was to deflate your tire, then pump it up to the target pressure you
chose, without the use of a gage. As I recall, there were guys who got
within a couple percent of their target.

Yes, I run my normal road bike tires at around 80 - 90 PSI and I can
hit this pressure pretty well without a gauge. But being told to pump
the tires to 37.5 PSI and even coming close is a whole different
situation.

As an aside, I've noticed that when sitting by the side of the road in
the rain and fixing a flat, and pumping up the tire with one of those
small hand pumps that the pressure I felt was "O.K." was substantially
below the pressure that I considered normal with my floor pump at home
:-)

--
Cheers,

John B.

On 2018-04-23 17:48, John B. wrote:

[...]

The Roman Legions apparently marched for about 2/3rds of a day
carrying their gear and weapons - a Century did have several mule
carts assigned for carrying tents and other gear - and then built a
camp before "falling out" for the night. According to Caesar's reports
from Gaul this went on for days at a time.


You believe Caesar's writers? I never did. Whenever they got beaten the
snot out of them they wrote "the winds were unfavorable" or whatever. If
they wrote the truth they'd likely have "disappeared".

--
Regards, Joerg

http://www.analogconsultants.com/

On Tue, 24 Apr 2018 07:51:23 -0700, Joerg
wrote:

On 2018-04-23 17:48, John B. wrote:

[...]

The Roman Legions apparently marched for about 2/3rds of a day
carrying their gear and weapons - a Century did have several mule
carts assigned for carrying tents and other gear - and then built a
camp before "falling out" for the night. According to Caesar's reports
from Gaul this went on for days at a time.


You believe Caesar's writers? I never did. Whenever they got beaten the
snot out of them they wrote "the winds were unfavorable" or whatever. If
they wrote the truth they'd likely have "disappeared".

Caesar was essentially a politician and wrote his reports specifically
to keep his name before both the population and the rulers of Rome
while he was absent from the city (I believe that he paid to have them
read publicly) and thus they were always complementary. However other
evidence does show that he generally did accomplish when he claimed to
have done.

For example, he claimed to have sold some 53,000 Adualeui into slavery
and independent sources show that the price of slaves in the
Mediterranean area dropped to all time lows in the same period, which
would tend to demonstrate that there was a large influx of slaves,
from somewhere, during this period.
--
Cheers,

John B.

On Wednesday, April 25, 2018 at 1:14:01 AM UTC+1, John B. wrote:
On Tue, 24 Apr 2018 07:51:23 -0700, Joerg
wrote:

On 2018-04-23 17:48, John B. wrote:

[...]

The Roman Legions apparently marched for about 2/3rds of a day
carrying their gear and weapons - a Century did have several mule
carts assigned for carrying tents and other gear - and then built a
camp before "falling out" for the night. According to Caesar's reports
from Gaul this went on for days at a time.


You believe Caesar's writers? I never did. Whenever they got beaten the
snot out of them they wrote "the winds were unfavorable" or whatever. If
they wrote the truth they'd likely have "disappeared".

Caesar was essentially a politician and wrote his reports specifically
to keep his name before both the population and the rulers of Rome
while he was absent from the city (I believe that he paid to have them
read publicly) and thus they were always complementary. However other
evidence does show that he generally did accomplish when he claimed to
have done.

For example, he claimed to have sold some 53,000 Adualeui into slavery
and independent sources show that the price of slaves in the
Mediterranean area dropped to all time lows in the same period, which
would tend to demonstrate that there was a large influx of slaves,
from somewhere, during this period.
--
Cheers,

John B.

Since you're interested in the period, John B., perhaps you'd like to answer this riddle:
The Romans imported enormous amountseeee of wheat from Egypt. What did they export in return in sufficient amounts to pay for all this grain?

Andre Jute
One of the disadvantages of a classical education is the sheer number of unanswered questions

On 4/24/2018 7:13 PM, John B. wrote:
On Tue, 24 Apr 2018 07:51:23 -0700, Joerg
wrote:

On 2018-04-23 17:48, John B. wrote:

[...]

The Roman Legions apparently marched for about 2/3rds of a day
carrying their gear and weapons - a Century did have several mule
carts assigned for carrying tents and other gear - and then built a
camp before "falling out" for the night. According to Caesar's reports
from Gaul this went on for days at a time.


You believe Caesar's writers? I never did. Whenever they got beaten the
snot out of them they wrote "the winds were unfavorable" or whatever. If
they wrote the truth they'd likely have "disappeared".

Caesar was essentially a politician and wrote his reports specifically
to keep his name before both the population and the rulers of Rome
while he was absent from the city (I believe that he paid to have them
read publicly) and thus they were always complementary. However other
evidence does show that he generally did accomplish when he claimed to
have done.

For example, he claimed to have sold some 53,000 Adualeui into slavery
and independent sources show that the price of slaves in the
Mediterranean area dropped to all time lows in the same period, which
would tend to demonstrate that there was a large influx of slaves,
from somewhere, during this period.


right, then four months ago, this:
http://www.dailymail.co.uk/sciencete...ain-found.html
--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971