Bike Stopping distances?

Bob who? writes:

Looking for a chart with bike stopping distances. Perhaps there's
something out there where they compared brake types, pads, tires,
etc - maybe even under wet and dry conditions?

That sounds more like a rider test than a brake test. If you do
straight line, dry road, braking tests with a good rider, he can raise
the rear wheel with the front brake for most brakes. You'll need a
more subjective test than that.

Just recall that the best racing brake on the market was the Campagnolo
Record side pull brake, yet avocational riders complained about not
being able to stop adequately, mainly because they had insufficient
strength in the index and middle finger to , for instance, raise the
rear wheel off the road.

Bicycle shops used the excuse that these were racing brakes and racers
only need to control speed, not stop all the time. Well that is a big
dodge do avoid telling the customer he is a weakling. The faster a
vehicle goes (bicycle , Motorcycle, car, etc) the better the brakes
must be... for stopping.

Anyway, the response was not fast for these complainers because the
mechanical advantage of the 1:1 caliper and 4:1 hand lever could not
be increased without reducing pad clearance. Motor vehicle brakes run
with essentially no clearance, the pads dragging on the discs all the
time... besides which they all have power assist except for mini-cars
and motorcycles.

In order to increase the ME of the brake it had to have a guaranteed
pad retraction on both pads. Off center pads were n0o longer an
option with the 5.6:1 ratio common in brakes today and to achieve that
function, the dual pivot brake was required. Unfortunately it made a
step backward in that the left (front) caliper arm (the one on the off
center pivot) has large angular contact error so that as it wears it
sweeps upward into the tire.

The low pad clearance has caused problems in racing where riders on
climbs noted that while standing, the rear brake made scraping noises
in the wet, the place where grit invariably gets on the rim. To avoid
the dragging brake syndrome, riders opened the brake QR on ascents but
often failed to close it for the descent, thus realizing too late that
the bicycle had only one brake.

To get around that, Campagnolo went back to a center pivot brake in
the rear that has the old 4:1 ratio and large pad clearance. So there
you are, back in the old days again.

Jobst Brandt

wrote:
Bob who? writes:


Looking for a chart with bike stopping distances. Perhaps there's
something out there where they compared brake types, pads, tires,
etc - maybe even under wet and dry conditions?


That sounds more like a rider test than a brake test. If you do
straight line, dry road, braking tests with a good rider, he can raise
the rear wheel with the front brake for most brakes. You'll need a
more subjective test than that.

Just recall that the best racing brake on the market was the Campagnolo
Record side pull brake, yet avocational riders complained about not
being able to stop adequately, mainly because they had insufficient
strength in the index and middle finger to , for instance, raise the
rear wheel off the road.

Bicycle shops used the excuse that these were racing brakes and racers
only need to control speed, not stop all the time. Well that is a big
dodge do avoid telling the customer he is a weakling. The faster a
vehicle goes (bicycle , Motorcycle, car, etc) the better the brakes
must be... for stopping.

Anyway, the response was not fast for these complainers because the
mechanical advantage of the 1:1 caliper and 4:1 hand lever could not
be increased without reducing pad clearance. Motor vehicle brakes run
with essentially no clearance, the pads dragging on the discs all the
time... besides which they all have power assist except for mini-cars
and motorcycles.

In order to increase the ME of the brake it had to have a guaranteed
pad retraction on both pads. Off center pads were n0o longer an
option with the 5.6:1 ratio common in brakes today and to achieve that
function, the dual pivot brake was required. Unfortunately it made a
step backward in that the left (front) caliper arm (the one on the off
center pivot) has large angular contact error so that as it wears it
sweeps upward into the tire.

The low pad clearance has caused problems in racing where riders on
climbs noted that while standing, the rear brake made scraping noises
in the wet, the place where grit invariably gets on the rim.

whoops. that would require lateral deflection jobst - surely you must
be mistaken...

To avoid
the dragging brake syndrome, riders opened the brake QR on ascents but
often failed to close it for the descent, thus realizing too late that
the bicycle had only one brake.

To get around that, Campagnolo went back to a center pivot brake in
the rear that has the old 4:1 ratio and large pad clearance. So there
you are, back in the old days again.

i've seen you repeat that baseless drivel a number of times - so, it was
nothing to do with weight reduction then... [rhetorical] especially
not in the face of lighter dura-ace [***DUAL PIVOT***] calipers...
/especially/ not since the running distance of the pad from the rim is
the same in both cases, but hey jobst, you don't let little things
called facts get in the way of a good opportunity to criticize anything
designed this side of 1970, do you...


Jobst Brandt

See responses below:

cel

wrote in message
...
Bob who? writes:

Looking for a chart with bike stopping distances. Perhaps there's
something out there where they compared brake types, pads, tires,
etc - maybe even under wet and dry conditions?

That sounds more like a rider test than a brake test. If you do
straight line, dry road, braking tests with a good rider, he can raise
the rear wheel with the front brake for most brakes. You'll need a
more subjective test than that.

Just recall that the best racing brake on the market was the Campagnolo
Record side pull brake, yet avocational riders complained about not
being able to stop adequately, mainly because they had insufficient
strength in the index and middle finger to , for instance, raise the
rear wheel off the road.

Bicycle shops used the excuse that these were racing brakes and racers
only need to control speed, not stop all the time. Well that is a big
dodge do avoid telling the customer he is a weakling. The faster a
vehicle goes (bicycle , Motorcycle, car, etc) the better the brakes
must be... for stopping.

Not everyone has a strong grip. Some can benifit from a greater mechanical
advantage, even with the drawbacks as you have stated. Better to be able to
stop well with small clearances, than to have poor braking with a weak grip.


Anyway, the response was not fast for these complainers because the
mechanical advantage of the 1:1 caliper and 4:1 hand lever could not
be increased without reducing pad clearance. Motor vehicle brakes run
with essentially no clearance, the pads dragging on the discs all the
time... besides which they all have power assist except for mini-cars
and motorcycles.

In order to increase the ME of the brake it had to have a guaranteed
pad retraction on both pads. Off center pads were n0o longer an
option with the 5.6:1 ratio common in brakes today and to achieve that
function, the dual pivot brake was required.

Other solutions can be devised, such as longer lever arms on the cable
actuated side of the lever arms, or cam operation as with the Campy deltas,
or current Zero Gravities. As you have mentioned before progressive action
such as the Delta brakes should be avoided. However cam operation can be
made to have a low mechanical advantage until the brakes almost touch the
rims and then to have a constant high mechanical advantage. Athough this
design may be problematic for some to adjust correctely.


Unfortunately it made a
step backward in that the left (front) caliper arm (the one on the off
center pivot) has large angular contact error so that as it wears it
sweeps upward into the tire.

See above.


The low pad clearance has caused problems in racing where riders on
climbs noted that while standing, the rear brake made scraping noises
in the wet, the place where grit invariably gets on the rim. To avoid
the dragging brake syndrome, riders opened the brake QR on ascents but
often failed to close it for the descent, thus realizing too late that
the bicycle had only one brake.

To get around that, Campagnolo went back to a center pivot brake in
the rear that has the old 4:1 ratio and large pad clearance. So there
you are, back in the old days again.

Jobst Brandt

anonymous snipes:

Looking for a chart with bike stopping distances. Perhaps there's
something out there where they compared brake types, pads, tires,
etc - maybe even under wet and dry conditions?

That sounds more like a rider test than a brake test. If you do
straight line, dry road, braking tests with a good rider, he can
raise the rear wheel with the front brake for most brakes. You'll
need a more subjective test than that.

Just recall that the best racing brake on the market was the
Campagnolo Record side pull brake, yet avocational riders
complained about not being able to stop adequately, mainly because
they had insufficient strength in the index and middle finger to ,
for instance, raise the rear wheel off the road.

Bicycle shops used the excuse that these were racing brakes and
racers only need to control speed, not stop all the time. Well
that is a big dodge do avoid telling the customer he is a weakling.
The faster a vehicle goes (bicycle , Motorcycle, car, etc) the
better the brakes must be... for stopping.

Not everyone has a strong grip. Some can benifit from a greater
mechanical advantage, even with the drawbacks as you have
stated. Better to be able to stop well with small clearances, than
to have poor braking with a weak grip.

That doesn't necessarily mean that all riders should be burdened with
the drawbacks of the dual pivot brake. These brakes cannot follow a
wobbly rim and jam if the wheel is out of true with, for instance one
broken spoke.

Anyway, the response was not fast for these complainers because the
mechanical advantage of the 1:1 caliper and 4:1 hand lever could
not be increased without reducing pad clearance. Motor vehicle
brakes run with essentially no clearance, the pads dragging on the
discs all the time... besides which they all have power assist
except for mini-cars and motorcycles.

In order to increase the ME of the brake it had to have a
guaranteed pad retraction on both pads. Off center pads were n0o
longer an option with the 5.6:1 ratio common in brakes today and to
achieve that function, the dual pivot brake was required.

Other solutions can be devised, such as longer lever arms on the
cable actuated side of the lever arms, or cam operation as with the
Campy deltas, or current Zero Gravities. As you have mentioned
before progressive action such as the Delta brakes should be
avoided. However cam operation can be made to have a low mechanical
advantage until the brakes almost touch the rims and then to have a
constant high mechanical advantage. Athough this design may be
problematic for some to adjust correctely.

That is not correct. The size of the human hand is the limit of
travel and that defines the stroke ratio of the mechanism. Variable
ratio brakes have been proven useless many times in the history of
brakes, both in motor vehicles and bicycles. The current brake levers
are well suited to hands but the resulting mechanical advantage, that
is easily altered in the caliper, is limited by the human hand to
brake clearance and lever ratio.

Unfortunately it made a step backward in that the left (front)
caliper arm (the one on the off center pivot) has large angular
contact error so that as it wears it sweeps upward into the tire.

See above.

I see nothing. Please explain. It took a long and well considered
development to arrive at the dual pivot design. It wasn't idly tossed
out there. If you think there is a simpler more useful way to make a
brake self centering, so that lower brake pad clearance is possible,
the bicycling industry would welcome the design.

The low pad clearance has caused problems in racing where riders on
climbs noted that while standing, the rear brake made scraping
noises in the wet, the place where grit invariably gets on the rim.
To avoid the dragging brake syndrome, riders opened the brake QR on
ascents but often failed to close it for the descent, thus
realizing too late that the bicycle had only one brake.

To get around that, Campagnolo went back to a center pivot brake in
the rear that has the old 4:1 ratio and large pad clearance. So
there you are, back in the old days again.

Jobst Brandt

See response below

Sorry, anonymous ~= less spam!

cel

wrote in message
...
anonymous snipes:

Looking for a chart with bike stopping distances. Perhaps there's
something out there where they compared brake types, pads, tires,
etc - maybe even under wet and dry conditions?

That sounds more like a rider test than a brake test. If you do
straight line, dry road, braking tests with a good rider, he can
raise the rear wheel with the front brake for most brakes. You'll
need a more subjective test than that.

Just recall that the best racing brake on the market was the
Campagnolo Record side pull brake, yet avocational riders
complained about not being able to stop adequately, mainly because
they had insufficient strength in the index and middle finger to ,
for instance, raise the rear wheel off the road.

Bicycle shops used the excuse that these were racing brakes and
racers only need to control speed, not stop all the time. Well
that is a big dodge do avoid telling the customer he is a weakling.
The faster a vehicle goes (bicycle , Motorcycle, car, etc) the
better the brakes must be... for stopping.

Not everyone has a strong grip. Some can benifit from a greater
mechanical advantage, even with the drawbacks as you have
stated. Better to be able to stop well with small clearances, than
to have poor braking with a weak grip.

That doesn't necessarily mean that all riders should be burdened with
the drawbacks of the dual pivot brake. These brakes cannot follow a
wobbly rim and jam if the wheel is out of true with, for instance one
broken spoke.


Agreed. However the feeble and weak, or persons of small stature can may
find that dual pivots are a good tradeoff for them. They tend to be lighter
in mass and with properly built wheels with 36 spokes they will only have to
adjust their brake shoes to compensate for the poor arc of dual pivots. I
also find the old side pulls total adequate with the proper brake shoes and
clean rims. They would be the best choice for those with sufficient hand
strength. Single pivot side pulls are still available for those who want
them, athough the high quality ones tend to be used or old stock.

Anyway, the response was not fast for these complainers because the
mechanical advantage of the 1:1 caliper and 4:1 hand lever could
not be increased without reducing pad clearance. Motor vehicle
brakes run with essentially no clearance, the pads dragging on the
discs all the time... besides which they all have power assist
except for mini-cars and motorcycles.

In order to increase the ME of the brake it had to have a
guaranteed pad retraction on both pads. Off center pads were n0o
longer an option with the 5.6:1 ratio common in brakes today and to
achieve that function, the dual pivot brake was required.

Other solutions can be devised, such as longer lever arms on the
cable actuated side of the lever arms, or cam operation as with the
Campy deltas, or current Zero Gravities. As you have mentioned
before progressive action such as the Delta brakes should be
avoided. However cam operation can be made to have a low mechanical
advantage until the brakes almost touch the rims and then to have a
constant high mechanical advantage. Athough this design may be
problematic for some to adjust correctely.

That is not correct. The size of the human hand is the limit of
travel and that defines the stroke ratio of the mechanism. Variable
ratio brakes have been proven useless many times in the history of
brakes, both in motor vehicles and bicycles. The current brake levers
are well suited to hands but the resulting mechanical advantage, that
is easily altered in the caliper, is limited by the human hand to
brake clearance and lever ratio.

Unfortunately it made a step backward in that the left (front)
caliper arm (the one on the off center pivot) has large angular
contact error so that as it wears it sweeps upward into the tire.

See above.

I see nothing. Please explain. It took a long and well considered
development to arrive at the dual pivot design. It wasn't idly tossed
out there. If you think there is a simpler more useful way to make a
brake self centering, so that lower brake pad clearance is possible,
the bicycling industry would welcome the design.

It meat to point out that the Zero Gravity design does not have the drawback
of the short arc on one of the arms. It has a high ratio like a dual pivot,
thus suffers from the poor pad to rim clearance of the dual pivot brakes,
but with the familiar single pivot arc. The cam action appear to function in
a non-progressive way, but I have not measured this quantitatively. Only my
subjective observation. They do suffer from poor centering compared to side
or dual pivots though.

See diagram at:
http://www.competitivecyclist.com/za...RODUCT.ID=1230



The low pad clearance has caused problems in racing where riders on
climbs noted that while standing, the rear brake made scraping
noises in the wet, the place where grit invariably gets on the rim.
To avoid the dragging brake syndrome, riders opened the brake QR on
ascents but often failed to close it for the descent, thus
realizing too late that the bicycle had only one brake.

To get around that, Campagnolo went back to a center pivot brake in
the rear that has the old 4:1 ratio and large pad clearance. So
there you are, back in the old days again.

Jobst Brandt

writes:
See response below

Sorry, anonymous ~= less spam!

cel

You can put your name in there just don't give them your address. On
the other hand, I don't get piles of spam, maybe two or three a day now
and then and my address has been out there for years.

That doesn't necessarily mean that all riders should be burdened
with the drawbacks of the dual pivot brake. These brakes cannot
follow a wobbly rim and jam if the wheel is out of true with, for
instance one broken spoke.

Agreed. However the feeble and weak, or persons of small stature can
may find that dual pivots are a good tradeoff for them. They tend to
be lighter in mass and with properly built wheels with 36 spokes
they will only have to adjust their brake shoes to compensate for
the poor arc of dual pivots. I also find the old side pulls total
adequate with the proper brake shoes and clean rims. They would be
the best choice for those with sufficient hand strength. Single
pivot side pulls are still available for those who want them,
although the high quality ones tend to be used or old stock.

As I said, that shouldn't mean that other brakes are no longer being
made, just because some riders have a weaker grip.

Anyway, the response was not fast for these complainers because
the mechanical advantage of the 1:1 caliper and 4:1 hand lever
could not be increased without reducing pad clearance. Motor
vehicle brakes run with essentially no clearance, the pads
dragging on the discs all the time... besides which they all
have power assist except for mini-cars and motorcycles.

In order to increase the ME of the brake it had to have a
guaranteed pad retraction on both pads. Off center pads were n0o
longer an option with the 5.6:1 ratio common in brakes today and
to achieve that function, the dual pivot brake was required.

Other solutions can be devised, such as longer lever arms on the
cable actuated side of the lever arms, or cam operation as with the
Campy deltas, or current Zero Gravities. As you have mentioned
before progressive action such as the Delta brakes should be
avoided. However cam operation can be made to have a low mechanical
advantage until the brakes almost touch the rims and then to have a
constant high mechanical advantage. Although this design may be
problematic for some to adjust correctly.

That is not correct. The size of the human hand is the limit of
travel and that defines the stroke ratio of the mechanism.
Variable ratio brakes have been proven useless many times in the
history of brakes, both in motor vehicles and bicycles. The
current brake levers are well suited to hands but the resulting
mechanical advantage, that is easily altered in the caliper, is
limited by the human hand to brake clearance and lever ratio.

Unfortunately it made a step backward in that the left (front)
caliper arm (the one on the off center pivot) has large angular
contact error so that as it wears it sweeps upward into the tire.

See above.

I see nothing. Please explain. It took a long and well considered
development to arrive at the dual pivot design. It wasn't idly
tossed out there. If you think there is a simpler more useful way
to make a brake self centering, so that lower brake pad clearance
is possible, the bicycling industry would welcome the design.

It meat to point out that the Zero Gravity design does not have the
drawback of the short arc on one of the arms. It has a high ratio
like a dual pivot, thus suffers from the poor pad to rim clearance
of the dual pivot brakes, but with the familiar single pivot
arc. The cam action appear to function in a non-progressive way, but
I have not measured this quantitatively. Only my subjective
observation. They do suffer from poor centering compared to side or
dual pivots though.

See diagram at:
http://www.competitivecyclist.com/za...RODUCT.ID=1230

A more useful picture is at:

http://tinyurl.com/bsgq5

where the cam is visible and the reason this brake can probably get by
without two pivots. Conspicuous is the return spring that doesn't
have external elephant ears that nearly all springs on caliper brakes
have. Those elephant ears are the center of rotation of the spring
ends and that causes sliding against the brake arm. This brake has
the coil concentric with the pivot bolt and has no sliding motion at
the contacts at the ends of the spring.

It is the sliding motion in a dirty environment that makes single
pivot brakes go off center. Apparently the designer of this brake was
aware of that and used a spring that will not cause off-center brake
pads. I made such a design for Campagnolo calipers but never got any
springs manufactured. With a bit of cleaning now and then, my brakes
work well enough to not warrant this exercise in spring winding
although it might be a nice retrofit that I'm sure others would like.

So the big question is: why do so many web-sites have pictures of the
front of the brake instead of a view that shows how it works? They
seem to love a mystery.

Jobst Brandt

wrote:

The low pad clearance [dual pivot brakes] has caused problems in racing where riders on
climbs noted that while standing, the rear brake made scraping noises
in the wet, the place where grit invariably gets on the rim. To avoid
the dragging brake syndrome, riders opened the brake QR on ascents but
often failed to close it for the descent, thus realizing too late that
the bicycle had only one brake.

To get around that, Campagnolo went back to a center pivot brake in
the rear that has the old 4:1 ratio and large pad clearance. So there
you are, back in the old days again.

Is this willful misinformation?

As far back as 1987, Campy was making detented sliding pin QRs mounted
in brake levers/bodies. These don't cause brake power loss when left
"open" as do caliper-mounted cam-style QRs, since there is no change in
cable length (cam QRs) or pivot points.

Maybe I missed an early iteration, but if all the dual pivot Campagnolo
brakes had this kind of QR (as do my older C Record "convertibles" and
a couple of sets of newer Chorus D brakes), when/how would a
Campy-equipped rider lose braking power by forgetting to click his pins
back "in" to "closed" position? The worst possible, you miss your first
grab at the lever because it opens a little further with the QR open.
But the brakes are there. No problem, no correction needed.

No, with the pin-style QRs for DP and centerpull calipers alike, we are
not "back in the old days" because Campy "D" brakes did not go back to
the inferior cam QR for the rear brake. --D-y

anonymous snipes:

The low pad clearance [dual pivot brakes] has caused problems in
racing where riders on climbs noted that while standing, the rear
brake made scraping noises in the wet, the place where grit
invariably gets on the rim. To avoid the dragging brake syndrome,
riders opened the brake QR on ascents but often failed to close it
for the descent, thus realizing too late that the bicycle had only
one brake.

To get around that, Campagnolo went back to a center pivot brake in
the rear that has the old 4:1 ratio and large pad clearance. So
there you are, back in the old days again.

Is this willful misinformation?

As far back as 1987, Campy was making detented sliding pin QRs
mounted in brake levers/bodies. These don't cause brake power loss
when left "open" as do caliper-mounted cam-style QRs, since there is
no change in cable length (cam QRs) or pivot points.

Oh? And you believe these riders could have used such brake levers
and that Campagnolo recently came up with this single pivot rear brake
so that we can have two kinds of calipers gratuitously. I think you
haven't analyzed the problem.

Maybe I missed an early iteration, but if all the dual pivot
Campagnolo brakes had this kind of QR (as do my older C Record
"convertibles" and a couple of sets of newer Chorus D brakes),
when/how would a Campy-equipped rider lose braking power by
forgetting to click his pins back "in" to "closed" position? The
worst possible, you miss your first grab at the lever because it
opens a little further with the QR open. But the brakes are there.
No problem, no correction needed.

This type of brake QR has the problem that it has too short a throw to
open the pads sufficiently to allow easy wheel changes. When that is
added to the higher mechanical advantage of the dual pivot brake you
have no QR, just a little more pad clearance.

No, with the pin-style QRs for DP and centerpull calipers alike, we
are not "back in the old days" because Campy "D" brakes did not go
back to the inferior cam QR for the rear brake.

I don't understand what this means. What features are you talking
about?

Jobst Brandt

wrote:

anonymous snipes:
Snipe? Wow, from the pro. Thanks!

("I" wrote):

As far back as 1987, Campy was making detented sliding pin QRs
mounted in brake levers/bodies. These don't cause brake power loss
when left "open" as do caliper-mounted cam-style QRs, since there is
no change in cable length (cam QRs) or pivot points.

(JB replied):

Oh? And you believe these riders could have used such brake levers
and that Campagnolo recently came up with this single pivot rear brake
so that we can have two kinds of calipers gratuitously.

No x3. Responding to your:

The low pad clearance [dual pivot brakes] has caused problems in
racing where riders on climbs noted that while standing, the rear
brake made scraping noises in the wet, the place where grit
invariably gets on the rim. To avoid the dragging brake syndrome,
riders opened the brake QR on ascents but often failed to close it
for the descent, thus realizing too late that the bicycle had only
one brake.

To get around that, Campagnolo went back to a center pivot brake in
the rear that has the old 4:1 ratio and large pad clearance. So
there you are, back in the old days again.

Since no braking power is lost with the sliding pin QRs left open,
Campy users didn't lose brake power by forgetting to close them. Other
brands with caliper mounted cam QR's, possible.

I think you
haven't analyzed the problem.

I think you find dual pivot brakes unacceptable. I think you don't like
pin QRs, either.

This type of brake QR has the problem that it has too short a throw to
open the pads sufficiently to allow easy wheel changes. When that is
added to the higher mechanical advantage of the dual pivot brake you
have no QR, just a little more pad clearance.

Aha! Right I was-- no, a DP brake won't follow a wavy rim like a
centerpull. Point taken. However, I use "real" sized, correctly labeled
23mm tires, no problem with wheel changes on the front. Pops right out
of there, I do it all the time. I don't need to run the (front) DP pads
right up against the rim, and there's plenty of brake power for my use
here in the hills of Austin. If I were in the mountains, maybe I'd use
the front adjuster, just as I've done, from need, with a centerpull
brake.

(Me again, in what with a reread seems to be plain English):
No, with the pin-style QRs for DP and centerpull calipers alike, we
are not "back in the old days" because Campy "D" brakes did not go
back to the inferior cam QR for the rear brake.

(JB):
I don't understand what this means. What features are you talking
about?

Why, the thrill of leaving the old cam QR open by mistake, of course.
That's "old days".
--Dustoynonymous

anonymous snipes again:


anonymous snipes:

Snipe? Wow, from the pro. Thanks!

Main Entry: snipe
Function: intransitive verb
Inflected Form(s): sniped; sniping

1 : to shoot at exposed individuals (as of an enemy's forces) from a
usually concealed point of vantage

I think that describes your rude and anonymous style accurately.

("I" wrote):

As far back as 1987, Campy was making detented sliding pin QRs
mounted in brake levers/bodies. These don't cause brake power
loss when left "open" as do caliper-mounted cam-style QRs, since
there is no change in cable length (cam QRs) or pivot points.

Oh? And you believe these riders could have used such brake levers
and that Campagnolo recently came up with this single pivot rear
brake so that we can have two kinds of calipers gratuitously.

No x3. Responding to your:

The low pad clearance [dual pivot brakes] has caused problems in
racing where riders on climbs noted that while standing, the rear
brake made scraping noises in the wet, the place where grit
invariably gets on the rim. To avoid the dragging brake
syndrome, riders opened the brake QR on ascents but often failed
to close it for the descent, thus realizing too late that the
bicycle had only one brake.

To get around that, Campagnolo went back to a center pivot brake
in the rear that has the old 4:1 ratio and large pad clearance.
So there you are, back in the old days again.

Since no braking power is lost with the sliding pin QRs left open,
Campy users didn't lose brake power by forgetting to close
them. Other brands with caliper mounted cam QR's, possible.

I think you haven't analyzed the problem.

I think you find dual pivot brakes unacceptable. I think you don't
like pin QRs, either.

What makes you think I find dual pivot brakes unacceptable?

This type of brake QR has the problem that it has too short a throw
to open the pads sufficiently to allow easy wheel changes. When
that is added to the higher mechanical advantage of the dual pivot
brake you have no QR, just a little more pad clearance.

Aha! Right I was-- no, a DP brake won't follow a wavy rim like a
centerpull. Point taken. However, I use "real" sized, correctly
labeled 23mm tires, no problem with wheel changes on the front.

I don't see how that helps people who ride other sizes of tires and
need a QR on the brakes to make a wheel change. Please explain how
that would work for such riders.

Pops right out of there, I do it all the time. I don't need to run
the (front) DP pads right up against the rim, and there's plenty of
brake power for my use here in the hills of Austin. If I were in
the mountains, maybe I'd use the front adjuster, just as I've done,
from need, with a centerpull brake.

Yes, go on. How does this address the problems I mentioned?

(Me again, in what with a reread seems to be plain English):

No, with the pin-style QRs for DP and centerpull calipers alike,
we are not "back in the old days" because Campy "D" brakes did not
go back to the inferior cam QR for the rear brake.

I don't understand what this means. What features are you talking
about?

Why, the thrill of leaving the old cam QR open by mistake, of course.
That's "old days".

I think I responded to a non responding thread. This is not making
progress.

Jobst Brandt