Why do some forks and frames have brake rotor size limits?

On 2017-10-30 07:13, jbeattie wrote:
On Monday, October 30, 2017 at 7:01:08 AM UTC-7, Frank Krygowski
wrote:
On Monday, October 30, 2017 at 1:46:15 AM UTC-4, Sir Ridesalot
wrote:

BTW, @ Joerg, when I said I rode hundreds of miles off-road, I
meant each year. For some very strange reason I don't wear out my
rims very fast even thouh I use cantilever brakes. I ride
according to the conditions. Again, traction is the MAIN
limiting factor in my braking off-road with or without the
bicycle fully loaded for 2+ weeks touring off-road. Asusual YOUR
needsare fardifferent from most everyone elses'

I think a lot of the differences depend on riding style. I was once
on a mountain bike ride when a different guy's rim split from wear
at the braking surface. Disc brakes would have prevented that, I'm
sure.


That happend on my sister's MTB which has rim brakes. The rim literally
exploded which was an instant ride-ending event. Luckily it was the rear
so no crash. It can make for a long walk home.


But I assume that his normal riding was almost as heroic and gnarly
as Joerg's. I've done some of that when I was much younger - for
example riding around some abandoned strip mines with younger
friends and doing things I'd never do now.


I am not a heroic rider. What we have are trails with embedded rocks
that stick out of the soil. The kind that provides good traction but
crushes bones if you turf it hard. Many little creeks and mud puddles
will cover the whole MTB within just a few miles in winter but inbetween
you can still step on it. And people like myself do. There are streches
where we go at less than 5mph and some above 20mph. The latter is where
the brakes just have to work in case a deer comes shooting out of the
brush or something.


But "off road" or "mountain biking" doesn't have to be risky or
gnarly, or require disc brakes or special equipment. See
http://www.bicyclinglife.com/Recreation/GrownUps.htm


Nice write-up. Thing is, that's a fun ride, a family outing where travel
time isn't very important. Some of us use the MTB for commutes and
errands. For example, the only way to get from here to Placerville is on
10mi of singletrack and that one requires good skills in some sections.
Even a lot of experienced riders have gotten hurt. Just to get to that
trail requires crossing turf such as this:

http://analogconsultants.com/ng/bike/Chapparal2.jpg

In winter that turns into a muddy creek.


Weight, mileage and weather conditions. Like I said, I work with a
guy who commutes every day about 12 miles each way, and he was going
through rims about every two years or less. He just switched to cable
discs. He's a big guy.


That's the other difference. I am almost what MTB riders call a clyde.
Tall and over 200lbs. Plus usually around 20lbs of baggage on the bike.
This is not unusual at all. The owner of the LBS where I bought my MTB
weighs over 250lbs and he's all muscle, no fat, rides in competitions.


... His rims were pretty robust Alex or some
mid-fi brand.


In the end it doesn't matter. Aluminum is aluminum, except for Sir who
must have access to rims in some high-faultin space-age material. Or
maybe he pussyfoots his MTB when the weather is bad.

--
Regards, Joerg

http://www.analogconsultants.com/

On Monday, October 30, 2017 at 7:05:28 AM UTC-7, Radey Shouman wrote:
Frank Krygowski writes:

On 10/29/2017 12:02 PM, wrote:
On Friday, October 27, 2017 at 6:04:58 PM UTC-7, Frank Krygowski wrote:
On 10/27/2017 8:42 PM, John B. wrote:
On Fri, 27 Oct 2017 08:06:33 -0700 (PDT), wrote:

[ ... ]


If the choice is to run into a car door or be run over by a car then I
think I'd get off and walk.

In practice, at least in my experience, the actual choice is between the
_risk_ of getting hit by an opening door, and the _risk_ of a motorist
deliberately running me over from behind.

In my experience, the latter risk is almost zero. Consider, we're almost
certainly talking about a place where there are witnesses, because the
situation requires people parking, getting out of their cars, opposing
traffic that would prevent the guy behind from changing lanes, etc.
There just aren't that many psychopaths who would risk prison terms by
deliberately running you over, especially because it would slow them down.

On the other hand, the person doing the dooring doesn't have to be a
psychopath. He just has to be inattentive. There are lots and lots of
those people.

Now, for corroboration: I have definitely had situations where a door
popped open, and I would have been doored if I had been riding within
reach. But while I've occasionally (but rarely) had motorists honk or
yell when I claim a lane, I've never had one run me over.

And let's remember that dooring can be fatal. If the door snags your
right handlebar, the bike whips to the right and you are instantaneously
thrown to the left, directly into the path of the cars you were so
worried about.

Where would these witnesses come from? The cars that simply continued driving?

I don't know, Tom, but let me repeat: I've had some motorists act
displeased when I've ridden at lane center. I've never had one run me
over. I've never known another cyclist who had that happen.

It seems to me that a driver who is screaming and honking is extremely
*unlikely* to actually hit you. It *could* happen if he's in poor
control of his vehicle, or is completely psychotic, but that's not the
way to bet.

The ones to watch out for seem to look directly at you, but the internal
picture just never develops, no malice at all. Riding further out in
the road does seem to help, because they are actively looking for motor
vehicle traffic.

Well, it certainly doesn't help to be wearing all black in the evening without lights. That was so popular for several years that it's almost unbelievable.

On 2017-10-29 18:02, John B. wrote:
On Sun, 29 Oct 2017 07:59:34 -0700, Joerg
wrote:

On 2017-10-28 17:18, John B. wrote:
On Sat, 28 Oct 2017 08:09:28 -0700, Joerg
wrote:

On 2017-10-27 17:11, John B. wrote:
On Fri, 27 Oct 2017 06:58:27 -0700, Joerg
wrote:

On 2017-10-27 01:11, John B. wrote:
On Wed, 25 Oct 2017 07:53:11 -0700, Joerg
wrote:

On 2017-10-24 17:21, John B. wrote:
On Tue, 24 Oct 2017 11:47:12 -0700, Joerg
wrote:

On 2017-10-24 07:27, wrote:
On Tuesday, October 24, 2017 at 2:19:48 AM UTC-7, John B. wrote:
On Mon, 23 Oct 2017 10:09:20 -0700, Jeff Liebermann
wrote:

On Mon, 23 Oct 2017 12:48:29 +0700, John B.
wrote:

On Sun, 22 Oct 2017 20:51:15 -0700, Jeff Liebermann
wrote:

On Mon, 23 Oct 2017 07:02:08 +0700, John B.
wrote:

But re disc brake cooling F1 car brakes appear to work with
the discs red hot. In the 1,000 degree (F) range. And they
use Carbon Fiber discs too :-) And everyone knows that CF
is better.

"Thermal Conductivity of Carbon Fiber, and other Carbon
Based Materials"
http://www.christinedemerchant.com/carbon_characteristics_heat_conductivity.html


"So...Is Carbon Fiber a good heat conductor?
As usual the answer is "it depends." The short answer is NO
not when regular carbon fiber is made up in regular epoxy and
expected to conduct heat across the thickness. IF a highly
carbonized pan fiber with graphite or diamond added, is
measured for heat transmission in the length of the fiber it
is very good and can rival and exceed copper."

On the other hand, they seem to work pretty well :-) See
https://www.youtube.com/watch?v=h5JcHAEmIYM for a visual
indication of heat dissipation. :-)

Impressive. I'll assume it's a carbon-carbon rotor, since all F1
cars seem to using them.

Undoubtedly so. But if the advantage of "carbon" bikes can be
extolled that a carbon-carbon frame must have twice the bragging
rights :-)


http://www.racecar-engineering.com/technology-explained/f1-2014-explained-brake-systems/


(4 pages)
"A typical road car uses a cast iron brake disc with an organic
brake pad. In an F1 car, though, the same material is used for
both disc and pad, and this material is known as carbon-carbon -
a significantly different material to the carbon-fibre
composites used in the rest of the car" In other words, the F1
brakes are NOT made from CF.

Some detail on Formula 1 brakes:
https://www.youtube.com/watch?v=ev6XTdlKElw

Fun destroying brakes:
https://www.youtube.com/watch?v=KslGsXMgmqg The brake starting
at 4:45 sure looks like CF but I'm not sure.

Maybe twin disk brakes would be easier?
http://nuovafaor.it//public/prodotto/75/nccrop/DOPPIO_FRENO_CROSS_ENDURO.jpg


https://i.ytimg.com/vi/Pvwj-WWlKkg/maxresdefault.jpg
https://gzmyu4ma9b-flywheel.netdna-ssl.com/wp-content/uploads/2011/09/Gatorbrake-dual-hydraulic-front-disc-brakes-carbon-rotors01.jpg


https://lh4.googleusercontent.com/-cDfAFWrGR6Q/VHKPsm-f6YI/AAAAAAAAX10/2FCyj87xs0g/s640/14%2520-%25201.jpg
https://www.minibikecraze.co.uk/wp-content/uploads/bs0978.jpg
https://endless-sphere.com/forums/viewtopic.php?f=28&t=56268

Given the coefficient of friction between a 1.25" wide rubber tire
(32mm) and a wet road probably dragging the feet will work. :-)

Joerg's experience is with full suspension MTB's. These things are
incredibly heavy and long wheelbased. He has his judgement of disks
and it is no doubt quite accurate for his experience and riding.

I have disks on a much lighter and shorter wheelbased bike. I know
the failings up close and personal. I simply cannot imagine WHY a
person would want a more complicated system than that offered by the
Campy Skeleton brakes.


The reason can be summed up in one word: Rain :-)

But last Sunday I started out my "weekend" ride in the rain. It had
been raining nearly all night and the roads had a lot of water on them
- note we have been having floods here in Bangkok lately - but it
appeared that the rain was ending so off I went.

Unfortunately my weather forecasting facility wasn't working very well
and I rode 20 Km of a 30 Km ride in light rain and flooded roads in
many places. I was splashing through water in some places and cars
were splashing through (and splashing me) in others.

Of course, Sunday is much lighter traffic then on work days but still,
Bangkok is rated as one of the cities with the most chaotic traffic
in the world, and I did have to stop suddenly several time, on flooded
roads with wet wheels and brakes.

My brakes worked just as they do in the dry. Back brake stops me
somewhat slowly and front brake stops rather suddenly, both brakes
together provides best stopping. No long wait after grabbing a brake
lever although I did think of you with your stopping problems and I
have the feeling that the brake lever pressure might be a tiny bit
more to stop in the rain but if it was it was so little that it
couldn't be quantified.

But of course I am using quality brake pads. Why it costs me US$12.12
a wheel just for pads alone.... but they do last a year or more.


It seems Californian rain and Thai rain aren't the same. When it rains
heavily and I have to do a surprise emergency stop after not having used
the brakes for a while there is 1-2sec of nada, absolutely nothing. It
makes no difference whatsoever whether I use $17 high-falutin Koolstop
rain-rated pads or $4 Clarks pads. The experience of other riders around
here and in this NG is similar.

Which, to be honest, I find a little mystifying as I've had pretty
constant success with conventional brakes.

Frankly, I can't believe this is solely because I'm somehow so
uniquely skilled or that y'all are all in the awkward squad

I do see a number of people here and many who are not here who seem to
have ridden for years using conventional brakes without complaint and
some of the blogs I read don't even talk about brakes. Dave Moulton,
for example. An old fellow, used to race bikes, came to the U.S. in
about 1979 and built frames commercially for years, now retired, has
one entry in his blog about brakes - "centering side pull brakes".

Another blog from the long distance side of the bicycleing world, The
Blayleys, who are into Audex's and who apparently each ride in the
neighborhood of 10,000 miles annually, mentions Vee brakes in
reference to a Tandem while a photo of them on a tandem on their web
page shows disc brakes. On the other hand, when she discusses a "good
brevet bike she simply says that the "brakes must clear the fenders
and probably long reach caliper brakes will suffice".

In short, it seems that brakes just don't seem to be a hot subject in
much of the cycling fraternity.


To a large part that is because most cyclist will not ride in driving
rain. Some do and those know exactly how that delay with rim brakes
feels. Occasionally it is called "free fall" because that's how it feels
like.

Well, the Blayleys state that the husband, John, has ridden 10 - 17
thousand miles a year for the past 25 years and the wife, Pamela, has
ridden from 10 - 14 thousand miles a year for the past 20 years, or
another way to put it might be that together they have ridden from 20
- 30 thousand miles a year for the past 20 years.

Somehow I suspect that they may have encountered rain in that period.


And grandpa has driven his cars without safety belts yet survived ...


Well, since you mentioned it. My two grandfathers, neither of whom
ever had a road accident. One died at 92 and the other at 87. My
father never had a road accident although he did get a speeding ticket
once, died at 87. My mother had one "accident", a guy ran a red light
and tee-boned her car, no speeding tickets, died at 86. All deaths
were considered "natural".

Do you really believe that safety belts would have benefited them?


Counting on luck alone is not smart. The father of a friend's wife died
from the consequences of a minor fender bender at an intersection
because he didn't wear a belt. That accident was 100% survivable. Or
would have been ...

So one of your friends died in a traffic accident and four of my
ancestors never had an accident at all. Thus safety belts are a good
idea?


Yes, they are. Ask any ER doctor who is old enough to remember the days
before safety belts and before motorcycle helmets. The folks who do or
did emergency surgery on traffic accident victims. My wife used to work
there so we know.

--
Regards, Joerg

http://www.analogconsultants.com/

On 2017-10-29 19:59, Frank Krygowski wrote:
On 10/29/2017 10:59 AM, Joerg wrote:
On 2017-10-28 17:18, John B. wrote:
On Sat, 28 Oct 2017 08:09:28 -0700, Joerg


Well, since you mentioned it. My two grandfathers, neither of whom
ever had a road accident. One died at 92 and the other at 87. My
father never had a road accident although he did get a speeding ticket
once, died at 87. My mother had one "accident", a guy ran a red light
and tee-boned her car, no speeding tickets, died at 86. All deaths
were considered "natural".

Do you really believe that safety belts would have benefited them?


Counting on luck alone is not smart. The father of a friend's wife
died from the consequences of a minor fender bender at an intersection
because he didn't wear a belt. That accident was 100% survivable. Or
would have been ...

I'd be interested to see the difference in one's lifetime odds of dying
in a traffic crash wearing seatbelts vs. not wearing them. I suspect the
difference isn't tremendous, since most people die of other things anyway.


It is tremendous for people who drive a lot. Example from your state:

http://www.springfieldnewssun.com/ne...oDZWpZQRBIpdJ/

For me it probably wouldn't matter much because my car mileage is now
below 1000mi/year but I never drive without belt. Ever.

And again, like with bicycle incidents death is not the only concern.
There is a far larger number of people suffering what is termed
life-changing accidents. Where there are serious longterm consequences.
This can be all the way from a permanent limp to a wheelchair.


Having said that: I do buckle up each time I ride or drive. That's
mostly because there is some benefit, and zero detriment.

However, I willingly ride in my friend's Model A that has no belts. When
our daughter got married, they rode from the wedding to the reception in
an elegant antique car with no belts, and nobody worried about the
possible tragedy of a wedding day fatality.

And if I, as a passenger, have to take my seatbelt off to reach
something in the back seat, remove a jacket or whatever, I don't hesitate.


Short episodes or rides in an antique car are different. Most serious
accident happen in foul weather and during commutes. Or when the other
drivers is hopelessly soused.

--
Regards, Joerg

http://www.analogconsultants.com/

On Monday, October 30, 2017 at 7:40:16 AM UTC-7, Joerg wrote:
On 2017-10-30 07:13, jbeattie wrote:
On Monday, October 30, 2017 at 7:01:08 AM UTC-7, Frank Krygowski
wrote:
On Monday, October 30, 2017 at 1:46:15 AM UTC-4, Sir Ridesalot
wrote:

BTW, @ Joerg, when I said I rode hundreds of miles off-road, I
meant each year. For some very strange reason I don't wear out my
rims very fast even thouh I use cantilever brakes. I ride
according to the conditions. Again, traction is the MAIN
limiting factor in my braking off-road with or without the
bicycle fully loaded for 2+ weeks touring off-road. Asusual YOUR
needsare fardifferent from most everyone elses'

I think a lot of the differences depend on riding style. I was once
on a mountain bike ride when a different guy's rim split from wear
at the braking surface. Disc brakes would have prevented that, I'm
sure.


That happend on my sister's MTB which has rim brakes. The rim literally
exploded which was an instant ride-ending event. Luckily it was the rear
so no crash. It can make for a long walk home.


But I assume that his normal riding was almost as heroic and gnarly
as Joerg's. I've done some of that when I was much younger - for
example riding around some abandoned strip mines with younger
friends and doing things I'd never do now.


I am not a heroic rider. What we have are trails with embedded rocks
that stick out of the soil. The kind that provides good traction but
crushes bones if you turf it hard. Many little creeks and mud puddles
will cover the whole MTB within just a few miles in winter but inbetween
you can still step on it. And people like myself do. There are streches
where we go at less than 5mph and some above 20mph. The latter is where
the brakes just have to work in case a deer comes shooting out of the
brush or something.


But "off road" or "mountain biking" doesn't have to be risky or
gnarly, or require disc brakes or special equipment. See
http://www.bicyclinglife.com/Recreation/GrownUps.htm


Nice write-up. Thing is, that's a fun ride, a family outing where travel
time isn't very important. Some of us use the MTB for commutes and
errands. For example, the only way to get from here to Placerville is on
10mi of singletrack and that one requires good skills in some sections.
Even a lot of experienced riders have gotten hurt. Just to get to that
trail requires crossing turf such as this:

http://analogconsultants.com/ng/bike/Chapparal2.jpg

In winter that turns into a muddy creek.


Weight, mileage and weather conditions. Like I said, I work with a
guy who commutes every day about 12 miles each way, and he was going
through rims about every two years or less. He just switched to cable
discs. He's a big guy.


That's the other difference. I am almost what MTB riders call a clyde.
Tall and over 200lbs. Plus usually around 20lbs of baggage on the bike.
This is not unusual at all. The owner of the LBS where I bought my MTB
weighs over 250lbs and he's all muscle, no fat, rides in competitions.


... His rims were pretty robust Alex or some
mid-fi brand.


In the end it doesn't matter. Aluminum is aluminum, except for Sir who
must have access to rims in some high-faultin space-age material. Or
maybe he pussyfoots his MTB when the weather is bad.

Joerg, heroics can also be described as riding a really heavy bike such as yours at any pace above mild.

On Monday, October 30, 2017 at 7:42:51 AM UTC-7, Joerg wrote:
On 2017-10-29 18:02, John B. wrote:
On Sun, 29 Oct 2017 07:59:34 -0700, Joerg
wrote:

On 2017-10-28 17:18, John B. wrote:
On Sat, 28 Oct 2017 08:09:28 -0700, Joerg
wrote:

On 2017-10-27 17:11, John B. wrote:
On Fri, 27 Oct 2017 06:58:27 -0700, Joerg
wrote:

On 2017-10-27 01:11, John B. wrote:
On Wed, 25 Oct 2017 07:53:11 -0700, Joerg
wrote:

On 2017-10-24 17:21, John B. wrote:
On Tue, 24 Oct 2017 11:47:12 -0700, Joerg
wrote:

On 2017-10-24 07:27, wrote:
On Tuesday, October 24, 2017 at 2:19:48 AM UTC-7, John B. wrote:
On Mon, 23 Oct 2017 10:09:20 -0700, Jeff Liebermann
wrote:

On Mon, 23 Oct 2017 12:48:29 +0700, John B.
wrote:

On Sun, 22 Oct 2017 20:51:15 -0700, Jeff Liebermann
wrote:

On Mon, 23 Oct 2017 07:02:08 +0700, John B.
wrote:

But re disc brake cooling F1 car brakes appear to work with
the discs red hot. In the 1,000 degree (F) range. And they
use Carbon Fiber discs too :-) And everyone knows that CF
is better.

"Thermal Conductivity of Carbon Fiber, and other Carbon
Based Materials"
http://www.christinedemerchant.com/carbon_characteristics_heat_conductivity.html


"So...Is Carbon Fiber a good heat conductor?
As usual the answer is "it depends." The short answer is NO
not when regular carbon fiber is made up in regular epoxy and
expected to conduct heat across the thickness. IF a highly
carbonized pan fiber with graphite or diamond added, is
measured for heat transmission in the length of the fiber it
is very good and can rival and exceed copper."

On the other hand, they seem to work pretty well :-) See
https://www.youtube.com/watch?v=h5JcHAEmIYM for a visual
indication of heat dissipation. :-)

Impressive. I'll assume it's a carbon-carbon rotor, since all F1
cars seem to using them.

Undoubtedly so. But if the advantage of "carbon" bikes can be
extolled that a carbon-carbon frame must have twice the bragging
rights :-)


http://www.racecar-engineering.com/technology-explained/f1-2014-explained-brake-systems/


(4 pages)
"A typical road car uses a cast iron brake disc with an organic
brake pad. In an F1 car, though, the same material is used for
both disc and pad, and this material is known as carbon-carbon -
a significantly different material to the carbon-fibre
composites used in the rest of the car" In other words, the F1
brakes are NOT made from CF.

Some detail on Formula 1 brakes:
https://www.youtube.com/watch?v=ev6XTdlKElw

Fun destroying brakes:
https://www.youtube.com/watch?v=KslGsXMgmqg The brake starting
at 4:45 sure looks like CF but I'm not sure.

Maybe twin disk brakes would be easier?
http://nuovafaor.it//public/prodotto/75/nccrop/DOPPIO_FRENO_CROSS_ENDURO.jpg


https://i.ytimg.com/vi/Pvwj-WWlKkg/maxresdefault.jpg
https://gzmyu4ma9b-flywheel.netdna-ssl.com/wp-content/uploads/2011/09/Gatorbrake-dual-hydraulic-front-disc-brakes-carbon-rotors01.jpg


https://lh4.googleusercontent.com/-cDfAFWrGR6Q/VHKPsm-f6YI/AAAAAAAAX10/2FCyj87xs0g/s640/14%2520-%25201.jpg
https://www.minibikecraze.co.uk/wp-content/uploads/bs0978.jpg
https://endless-sphere.com/forums/viewtopic.php?f=28&t=56268

Given the coefficient of friction between a 1.25" wide rubber tire
(32mm) and a wet road probably dragging the feet will work. :-)

Joerg's experience is with full suspension MTB's. These things are
incredibly heavy and long wheelbased. He has his judgement of disks
and it is no doubt quite accurate for his experience and riding.

I have disks on a much lighter and shorter wheelbased bike. I know
the failings up close and personal. I simply cannot imagine WHY a
person would want a more complicated system than that offered by the
Campy Skeleton brakes.


The reason can be summed up in one word: Rain :-)

But last Sunday I started out my "weekend" ride in the rain. It had
been raining nearly all night and the roads had a lot of water on them
- note we have been having floods here in Bangkok lately - but it
appeared that the rain was ending so off I went.

Unfortunately my weather forecasting facility wasn't working very well
and I rode 20 Km of a 30 Km ride in light rain and flooded roads in
many places. I was splashing through water in some places and cars
were splashing through (and splashing me) in others.

Of course, Sunday is much lighter traffic then on work days but still,
Bangkok is rated as one of the cities with the most chaotic traffic
in the world, and I did have to stop suddenly several time, on flooded
roads with wet wheels and brakes.

My brakes worked just as they do in the dry. Back brake stops me
somewhat slowly and front brake stops rather suddenly, both brakes
together provides best stopping. No long wait after grabbing a brake
lever although I did think of you with your stopping problems and I
have the feeling that the brake lever pressure might be a tiny bit
more to stop in the rain but if it was it was so little that it
couldn't be quantified.

But of course I am using quality brake pads. Why it costs me US$12.12
a wheel just for pads alone.... but they do last a year or more..


It seems Californian rain and Thai rain aren't the same. When it rains
heavily and I have to do a surprise emergency stop after not having used
the brakes for a while there is 1-2sec of nada, absolutely nothing. It
makes no difference whatsoever whether I use $17 high-falutin Koolstop
rain-rated pads or $4 Clarks pads. The experience of other riders around
here and in this NG is similar.

Which, to be honest, I find a little mystifying as I've had pretty
constant success with conventional brakes.

Frankly, I can't believe this is solely because I'm somehow so
uniquely skilled or that y'all are all in the awkward squad

I do see a number of people here and many who are not here who seem to
have ridden for years using conventional brakes without complaint and
some of the blogs I read don't even talk about brakes. Dave Moulton,
for example. An old fellow, used to race bikes, came to the U.S. in
about 1979 and built frames commercially for years, now retired, has
one entry in his blog about brakes - "centering side pull brakes"..

Another blog from the long distance side of the bicycleing world, The
Blayleys, who are into Audex's and who apparently each ride in the
neighborhood of 10,000 miles annually, mentions Vee brakes in
reference to a Tandem while a photo of them on a tandem on their web
page shows disc brakes. On the other hand, when she discusses a "good
brevet bike she simply says that the "brakes must clear the fenders
and probably long reach caliper brakes will suffice".

In short, it seems that brakes just don't seem to be a hot subject in
much of the cycling fraternity.


To a large part that is because most cyclist will not ride in driving
rain. Some do and those know exactly how that delay with rim brakes
feels. Occasionally it is called "free fall" because that's how it feels
like.

Well, the Blayleys state that the husband, John, has ridden 10 - 17
thousand miles a year for the past 25 years and the wife, Pamela, has
ridden from 10 - 14 thousand miles a year for the past 20 years, or
another way to put it might be that together they have ridden from 20
- 30 thousand miles a year for the past 20 years.

Somehow I suspect that they may have encountered rain in that period.


And grandpa has driven his cars without safety belts yet survived ....


Well, since you mentioned it. My two grandfathers, neither of whom
ever had a road accident. One died at 92 and the other at 87. My
father never had a road accident although he did get a speeding ticket
once, died at 87. My mother had one "accident", a guy ran a red light
and tee-boned her car, no speeding tickets, died at 86. All deaths
were considered "natural".

Do you really believe that safety belts would have benefited them?


Counting on luck alone is not smart. The father of a friend's wife died
from the consequences of a minor fender bender at an intersection
because he didn't wear a belt. That accident was 100% survivable. Or
would have been ...

So one of your friends died in a traffic accident and four of my
ancestors never had an accident at all. Thus safety belts are a good
idea?


Yes, they are. Ask any ER doctor who is old enough to remember the days
before safety belts and before motorcycle helmets. The folks who do or
did emergency surgery on traffic accident victims. My wife used to work
there so we know.

Before motorcycle safety helmets people would present in ER's with lots of serious looking head wounds that would turn out to be mostly superficial and the occasional skull fracture. Now they usually present at the morgue with over-confidence caused fatal concussion without skull fractures.

The number of motorcycle deaths before and after "safety" helmets has not changed.

There were little to no head injuries on racing motorcycles simply because they weren't generally involved in high speed collisions.

There doesn't seem to be any concern about the false claim that helmets save lives. Instead helmets save minor head wounds in minor accidents.

On Monday, October 30, 2017 at 7:51:42 AM UTC-7, Joerg wrote:
On 2017-10-29 19:59, Frank Krygowski wrote:
On 10/29/2017 10:59 AM, Joerg wrote:
On 2017-10-28 17:18, John B. wrote:
On Sat, 28 Oct 2017 08:09:28 -0700, Joerg


Well, since you mentioned it. My two grandfathers, neither of whom
ever had a road accident. One died at 92 and the other at 87. My
father never had a road accident although he did get a speeding ticket
once, died at 87. My mother had one "accident", a guy ran a red light
and tee-boned her car, no speeding tickets, died at 86. All deaths
were considered "natural".

Do you really believe that safety belts would have benefited them?


Counting on luck alone is not smart. The father of a friend's wife
died from the consequences of a minor fender bender at an intersection
because he didn't wear a belt. That accident was 100% survivable. Or
would have been ...

I'd be interested to see the difference in one's lifetime odds of dying
in a traffic crash wearing seatbelts vs. not wearing them. I suspect the
difference isn't tremendous, since most people die of other things anyway.


It is tremendous for people who drive a lot. Example from your state:

http://www.springfieldnewssun.com/ne...oDZWpZQRBIpdJ/

For me it probably wouldn't matter much because my car mileage is now
below 1000mi/year but I never drive without belt. Ever.

And again, like with bicycle incidents death is not the only concern.
There is a far larger number of people suffering what is termed
life-changing accidents. Where there are serious longterm consequences.
This can be all the way from a permanent limp to a wheelchair.


Having said that: I do buckle up each time I ride or drive. That's
mostly because there is some benefit, and zero detriment.

However, I willingly ride in my friend's Model A that has no belts. When
our daughter got married, they rode from the wedding to the reception in
an elegant antique car with no belts, and nobody worried about the
possible tragedy of a wedding day fatality.

And if I, as a passenger, have to take my seatbelt off to reach
something in the back seat, remove a jacket or whatever, I don't hesitate.


Short episodes or rides in an antique car are different. Most serious
accident happen in foul weather and during commutes. Or when the other
drivers is hopelessly soused.

I don't think that you have anything to worry about. In the US you have about 10 fatalities for every three trillion miles traveled. The chances of your getting in a wreck as a passenger in a car for the perhaps a minute out of your seatbelt is negligible.

On 2017-10-29 12:57, wrote:
On Sunday, October 29, 2017 at 10:02:12 AM UTC-7, Joerg wrote:
On 2017-10-29 09:45, wrote:
On Saturday, October 28, 2017 at 8:09:18 AM UTC-7, Joerg wrote:

And grandpa has driven his cars without safety belts yet survived
...

For people who do not shy away from unpaved roads or use a lot of
singletrack and ride in the rain there is a much more extreme
issue: Wet mud.

There is NO brake the is proof against wet mud. In fact it is perhaps
worse on a disk since the additional pressure of the pads can turn
the silicon present in most muds into cutting instruments that on rim
brakes cuts into the rubber show rather than the hard and thin disk
pad.


Actually, no. I've had mud literally dripping from the calipers which
had become barely recognizable brownish blobs. The only thing that
happens is that they make an awful grinding noise just like muddy rim
brakes do. With the two major differences that they still come on full
force immediately and that this grinding does not eat up aluminum.
Aluminum as one of the braking surfaces plain does not make any sense,
certainly not in a muddy environment.

A downside of bicycle disc brakes is that in contrast to most motor
vehicles the rotors have "vent holes" and weight weenie spiders. This
results in rather fast heat-up and in "brake mousse" when you plow
through thick vegetation on an overgrown trail. Mashed star-thistle and
other weeds get shredded and a sort of pulp develops which cakes up in
the holes of the rotor. It doesn't diminish the brake force but lets of
a bad stench. One of the reasons why I carry a Swiss Army knife in a
pocket. Not in a pannier, so I can whip it out in seconds. This also
helps in poking out the giant mud clump that forms behind the BB and can
prevent the rear wheel from turning.

Joerg - that additional noise is wear.


Sure. However, the rotors last thousands of miles, cost around $20 and
take only minutes to change. The pads cost $2/pair for ceramic-based
material (like motorcycles have) and last around 1000mi depending on
turf and weather. That is way more hassle than with a motor vehicle but
way less hassle than swapping out a shot rim.

I started riding again in fall 2013, using an older model MTB with
almost zero miles on it. By the end of 2013 it had around 1000mi on it
and the front rim looks horrible.

The problem in our area is this: Mud contains granules of decomposed
granite. Rubber pads need water diverter grooves and the granules lodge
in these grooves. They also pierce the rubber itself and lodge in there.
When pulling the lever that lets of a horrid grinding noise. Coming down
a hill you have to keep the brake engaged and you can literally hear the
rim being tortured all the way to the bottom of the hill. On flat
surfaces you have to stop and pry out the granules. On a rainy day that
means stopping every few miles. I stand by my opinion that rim brakes
are inadequate for any serious MTB riding.

--
Regards, Joerg

http://www.analogconsultants.com/

On 10/29/2017 7:09 PM, Frank Krygowski wrote:
On 10/29/2017 12:02 PM, wrote:
On Friday, October 27, 2017 at 6:04:58 PM UTC-7, Frank
Krygowski wrote:
On 10/27/2017 8:42 PM, John B. wrote:
On Fri, 27 Oct 2017 08:06:33 -0700 (PDT),
wrote:

On Friday, October 27, 2017 at 1:24:49 AM UTC-7, John
B. wrote:
On Thu, 26 Oct 2017 13:37:00 -0400, Radey Shouman
wrote:

Joerg writes:

On 2017-10-24 17:21, John B. wrote:
On Tue, 24 Oct 2017 11:47:12 -0700, Joerg

wrote:

[ ... ]

The reason can be summed up in one word: Rain :-)

But last Sunday I started out my "weekend" ride in
the rain. It had
been raining nearly all night and the roads had a
lot of water on them
- note we have been having floods here in Bangkok
lately - but it
appeared that the rain was ending so off I went.

Unfortunately my weather forecasting facility
wasn't working very well
and I rode 20 Km of a 30 Km ride in light rain and
flooded roads in
many places. I was splashing through water in some
places and cars
were splashing through (and splashing me) in others.

Of course, Sunday is much lighter traffic then on
work days but still,
Bangkok is rated as one of the cities with the
most chaotic traffic
in the world, and I did have to stop suddenly
several time, on flooded
roads with wet wheels and brakes.

My brakes worked just as they do in the dry. Back
brake stops me
somewhat slowly and front brake stops rather
suddenly, both brakes
together provides best stopping. No long wait after
grabbing a brake
lever although I did think of you with your
stopping problems and I
have the feeling that the brake lever pressure
might be a tiny bit
more to stop in the rain but if it was it was so
little that it
couldn't be quantified.

But of course I am using quality brake pads. Why it
costs me US$12.12
a wheel just for pads alone.... but they do last a
year or more.


It seems Californian rain and Thai rain aren't the
same. When it rains
heavily and I have to do a surprise emergency stop
after not having
used the brakes for a while there is 1-2sec of nada,
absolutely
nothing. It makes no difference whatsoever whether I
use $17
high-falutin Koolstop rain-rated pads or $4 Clarks
pads. The
experience of other riders around here and in this
NG is similar.

I don't understand the difference myself. When it's
really raining,
meaning there's a continuous film of water on the
road and a rooster
tail shooting forward off the front tire, I ride like
a little old lady,
because of the delay in braking. Especially when
it's dark, and leaves
and other blown down crap cover the road.

I suspect that may be the secret. I've never been
"doored", perhaps
because if I have to ride past a line of parked cars
where a door
might be opened I either slow down or ride further
enough away that a
door wouldn't hit me.

Here the bike lane can be so narrow that the car door
on a two-door totally covers the lane and there's no
place to dodge because passing cars will spot that and
not let you out.

If the choice is to run into a car door or be run over
by a car then I
think I'd get off and walk.

In practice, at least in my experience, the actual choice
is between the
_risk_ of getting hit by an opening door, and the
_risk_ of a motorist
deliberately running me over from behind.

In my experience, the latter risk is almost zero.
Consider, we're almost
certainly talking about a place where there are
witnesses, because the
situation requires people parking, getting out of their
cars, opposing
traffic that would prevent the guy behind from changing
lanes, etc.
There just aren't that many psychopaths who would risk
prison terms by
deliberately running you over, especially because it
would slow them down.

On the other hand, the person doing the dooring doesn't
have to be a
psychopath. He just has to be inattentive. There are lots
and lots of
those people.

Now, for corroboration: I have definitely had situations
where a door
popped open, and I would have been doored if I had been
riding within
reach. But while I've occasionally (but rarely) had
motorists honk or
yell when I claim a lane, I've never had one run me over.

And let's remember that dooring can be fatal. If the door
snags your
right handlebar, the bike whips to the right and you are
instantaneously
thrown to the left, directly into the path of the cars
you were so
worried about.

Where would these witnesses come from? The cars that
simply continued driving?

I don't know, Tom, but let me repeat: I've had some
motorists act displeased when I've ridden at lane center.
I've never had one run me over. I've never known another
cyclist who had that happen.

It doesn't pay to be timid. Man up.


I ride as you describe. But I understand everyone makes his
own choice about risk and behavior. The outliers (e.g.,
spaced out texting idiots) are outliers:

http://www.startribune.com/probation...ver/397338931/

But society does not value pedestrian or cyclist lives.

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

On 2017-10-30 08:33, wrote:
On Monday, October 30, 2017 at 7:40:16 AM UTC-7, Joerg wrote:
On 2017-10-30 07:13, jbeattie wrote:

[...]


Weight, mileage and weather conditions. Like I said, I work with
a guy who commutes every day about 12 miles each way, and he was
going through rims about every two years or less. He just
switched to cable discs. He's a big guy.


That's the other difference. I am almost what MTB riders call a
clyde. Tall and over 200lbs. Plus usually around 20lbs of baggage
on the bike. This is not unusual at all. The owner of the LBS where
I bought my MTB weighs over 250lbs and he's all muscle, no fat,
rides in competitions.


... His rims were pretty robust Alex or some mid-fi brand.


In the end it doesn't matter. Aluminum is aluminum, except for Sir
who must have access to rims in some high-faultin space-age
material. Or maybe he pussyfoots his MTB when the weather is bad.

Joerg, heroics can also be described as riding a really heavy bike
such as yours at any pace above mild.


That's not heroic because it doesn't come with additional risk. Over
time you just build up a lot of leg muscle. This also helps for rides
with the road bike like yesterday. I rode along a canal bike path purely
for exercise. It's otherwise a boring ride but ... no speed limit ...
woohoo! The path sometimes tunnels underneath roads and such but for
some obstacles it runs above, steep sections. With enough leg muscle you
don't have to shift, just leave it in high gear, put on the coals so you
reach 25mph or more at the bottom, keep the torque on until it crests
and then let it coast back down. I didn't shift at all until I reached
the Cosumnes River where I had my snack break. Four years ago I couldn't
have done that.

--
Regards, Joerg

http://www.analogconsultants.com/