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

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.

On Sunday, October 29, 2017 at 9:56:02 AM UTC-7, wrote:
On Saturday, October 28, 2017 at 4:59:49 PM UTC-7, jbeattie wrote:
On Saturday, October 28, 2017 at 3:40:36 PM UTC-7, AMuzi wrote:
On 10/28/2017 4:27 PM, jbeattie wrote:
On Saturday, October 28, 2017 at 12:08:44 PM UTC-7, Sir Ridesalot wrote:
On Saturday, October 28, 2017 at 11:09:18 AM UTC-4, 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 ...

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. You may have never encountered it but I have many times. You reach
in and, after a second or two of nothing, the rim brakes come on but let
off an awful grinding noise. You can literally hear the rim being
tortured but because of a rapidly approaching curve you can't let go. As
I have mentioned before the rims on my old MTB are only 1000mi old but
the front rim is almost shot from all that. Deep grooves.

I stand by my opinion that rim brakes are fair weather brakes. Then they
are fine but not when the going gets tough. Like this kind of weather:

https://www.youtube.com/watch?v=mX_EKybzK4Y


I might comment that I've ridden coaster brakes, drum brakes, rod pull
brakes, cantilever brakes, side pull single pivot caliper brakes,
double pivot caliper, Vee brakes and for one short ride a cable disc
brake. and at the time I rode them I found all the brakes to give
acceptable service. Well with one exception, rim brakes and chrome
plated steel rims were sometimes a bit iffy :-)


Yes, those were the worst. It got a little better with aluminum rims but
not a lot. In the world of automotive such a brake "system" would not
stand the slightest change of being legal.

Finally after many decades the bicycle industry woke up and adopted what
the automotive guys had all along, disc brakes. Why should I accept an
inferior brake system on a new bike when there is a much better one?

Well, when I worked on airplanes I remember that the F-4 had multi
plate disc brakes which provided a tremendous amount of stopping power
in a very small package.


Some tandems have that as well, and of course motorcycles: Two discs up
front. But not stacks of discs.


One supposes that will be next big improvement in bicycle brakes.. Or
perhaps a drag chute for those long downhill's to keep the rims from
melting?


I've thought about it :-)

--
Regards, Joerg

http://www.analogconsultants.com/

Oh ****! I've ridden many hundreds of miles off road in dry and wet sand, mud, heavy rain, rutted roads/trails and did so on an MTB with cantilever brakes and NEVER had trouble stopping either when I needed to or when I wanted too. I've ridden on ice and in 4 inches+ deep snowand also never had trouble stopping.

Perhaps you ride too fast for the conditions/sight lines or you don't keep your brakes adjusted properly.

Really? I have trouble standing up on ice. There is a point at which you don't want super-strong brakes.

-- Jay Beattie.


Yeah me too.
Snow is one thing - I'm used to that- but ice is quite
another. Depending on the recent weather, a frozen slick
patch of ice under snow will dump me right on my ass. We
mere humans would have some trouble with Jobst's famous tour
down a frozen Swiss river.

I live at a whopping 400 feet (about) elevation. The garage in my building is probably 0 feet. That minor elevation change sometimes means the difference between ice and no ice -- so I walk outside in the morning and say f*** this! And then I jump in the car and half-way to work, creeping along in traffic, there is no ice -- and then I regret not riding. So, in order to avoid that regret, I have done some pretty stupid sh** spinning around on ice or hoofing it in my SPDs to get out of my neighborhood and then being freaked out riding over the slick bridges and viaducts into town. I met up with another guy on a bike who was fish-tailing down the road on one of those mornings, and we looked at each other and shook our heads -- "we're a couple of idiots." So, now I'm working on not feeling regret or guilt if I drive. And don't get me going about the dopes who jump into their Malibus with no-season/no-tread tires and crash on the ice and/or snow. I'll slap on the snow tires in November. I really miss studs, but I'm doing penance with studless.

What sort of clothes do you wear to ride to work? And do you change at work or what?

A local job in a very convenient location is probably within riding distance but the position (at HALF of what it should be paying) will probably need neat attire.

I wear cycling clothes, change at work and rotate my work-clothes through the laundry in the lobby of my building. I've always commuted by bike and never worked more than 12 miles from home. There have been periods when I lived within a few miles of work, and I wore my work pants and kept shirts, ties and shoes at work -- which I did mostly in California because it hardly ever rained.

-- Jay Beattie.

On Sunday, October 29, 2017 at 2:02:17 PM UTC-7, jbeattie wrote:
On Sunday, October 29, 2017 at 9:56:02 AM UTC-7, wrote:

What sort of clothes do you wear to ride to work? And do you change at work or what?

A local job in a very convenient location is probably within riding distance but the position (at HALF of what it should be paying) will probably need neat attire.

I wear cycling clothes, change at work and rotate my work-clothes through the laundry in the lobby of my building. I've always commuted by bike and never worked more than 12 miles from home. There have been periods when I lived within a few miles of work, and I wore my work pants and kept shirts, ties and shoes at work -- which I did mostly in California because it hardly ever rained.

Thanks for the advice Jay.

On 10/29/2017 11:08 AM, wrote:
And if you DO try [to move into the traffic lane] you have cars behind you honking their horns.

Aww. Too bad!

--
- Frank Krygowski

On 10/29/2017 12:00 PM, wrote:
On Friday, October 27, 2017 at 5:55:22 PM UTC-7, Frank Krygowski wrote:
On 10/27/2017 5:40 PM, wrote:
On Friday, October 27, 2017 at 9:39:06 AM UTC-7, Frank Krygowski wrote:
On 10/27/2017 11:06 AM, wrote:
On Friday, October 27, 2017 at 1:24:49 AM UTC-7, John B. wrote:
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.

In my experience, the trick is to plan ahead. If I've got to move left
to avoid parked cars, etc. I tend to do it earlier rather than later.

And it may be different in other places, I suppose. (Over the years,
we've heard lots of "But the drivers HERE are really mean!") But the
shopping trip I make almost daily by bike has me leaving the store on a
street that's wide enough to share for about one block; then it gets
narrow. I stay to the right for the first part, but move left for the
narrow part. It sometimes involves looking over my shoulder at the next
motorist and signaling left to sort of negotiate; but I can't recall a
time when I wasn't allowed to merge left.

Sometimes I have to be a bit pushy. Riding in downtown Pittsburgh a few
weeks ago I came to an oddball intersection. (Pittsburgh has many.) I
had to turn right then immediately move into a left turn lane at a
traffic light.

A woman driving an SUV from the opposite direction wanted to turn left
into the same space I was using, and she tried to intimidate me into
staying at the curb. I just looked at her and kept my path, and she
stayed back.

Of course, when the light finally turned green and our ways parted, she
blared her horn. Because, you know, it was SO frustrating to have to sit
behind a bicycle, instead of being ten feet further ahead at the traffic
light!

Exactly how do you plan ahead for someone opening their door?

I don't ride in a door zone. Ever.

So you don't ride in the bike lanes. Virtually all but the very newest are in the door zone.

We have blessedly few bike lanes around here. But you're right; when a
bike lane puts me in a door zone, I don't use the bike lane. This is
specifically permissible under Ohio law ORC 4511.55(C).

If most of your bike lanes are in the door zone, and despite that you're
really required to ride there, you need much better bicycling advocacy.

--
- Frank Krygowski

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.

--
- Frank Krygowski

On Sunday, October 29, 2017 at 8:22:35 AM UTC-7, wrote:
On Friday, October 27, 2017 at 5:11:29 PM UTC-7, John B. wrote:

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.

For three years while between jobs I road almost continuously including several long distance tours each year. I barely made 10,000 miles per year and usually only cleared that hurdle with a last minute sprint. So unless the Blayley's are on a continuous tour I would question those miles.

Nah, there are people who have no family, no weeknight gig in the local community band, no garage beer-brewing operation, no lawn mowing, no house painting, etc., etc. They get on their bikes and grind-out miles. Usually not races -- but some sort of odd-ball endurance event for the marginally socialized. I'm like you, I rode 10K years when I was racing. I mostly lived in an apartment, and my wife was also racing. No kids. Rode every night after work and both days on the weekend. Hung out with other cyclists. After a while, you say f*** that! I'm going skiing! Or I'm doing something that is not riding.

I rode with some of these people on a few rides with a local "touring" club including this one guy who was a bicycle zombie -- you couldn't get him to talk. He just had this crazed 200 yard stare down the road . . . grinding, grinding. Okey-dokey. You have yourself a good ride, there! I'd drop back and talk with the disgruntled divorced guys for a while. A lot of these people did staggering miles. But they weren't my cup of tea.

-- Jay Beattie.

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?

--
Cheers,

John B.

On Sun, 29 Oct 2017 08:08:25 -0700 (PDT), wrote:

And if you DO try you have cars behind you honking their horns.

I'm pretty sure that the last time someone honked at me, I was in New
York -- and we moved here in the first year of the new millennium.

In Albany County, New York, honking upon seeing a bicycle on a county
road was part of the culture. Some of them forgot, and honked *after*
passing. Often, one could inhibit the honk by riding in the middle of
the lane, then shifting into the right wheel track after conspicuously
turning one's head.

Honking didn't happen on city streets.

--
Joy Beeson
joy beeson at comcast dot net
http://wlweather.net/PAGEJOY/

On Sun, 29 Oct 2017 08:22:33 -0700 (PDT), wrote:

On Friday, October 27, 2017 at 5:11:29 PM UTC-7, John B. wrote:

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.

For three years while between jobs I road almost continuously including several long distance tours each year. I barely made 10,000 miles per year and usually only cleared that hurdle with a last minute sprint. So unless the Blayley's are on a continuous tour I would question those miles.


YOU might. But the Husband, John, who doesn't have driver's license.
for a number of years rode 17 miles to work and 17 miles back.
Assuming a 5 day work week and a two week vacation period, that is
8,500 miles a year just to get to work and back. All you need is a
couple of the longer brevets and you hit 10,000.

"Longer brevet" like the Boston - Montreal - Boston was essentially a
1,200 Km, non stop, bicycle ride... or at least as non stop as you can
make it :-)
--
Cheers,

John B.