Better Braking?

On Thursday, January 30, 2020 at 8:25:18 PM UTC-5, AMuzi wrote:
On 1/30/2020 6:11 PM, Frank Krygowski wrote:
On 1/30/2020 5:18 PM, Tim McNamara wrote:
On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich
wrote:
I've been looking only at the advertisements for direct
mount brakes.
...

The pictures I have seen show the cable entering the brake
exactly like
a sidepull brake, but the pivots are reminiscent of Mafac
Racers with
brazed-on posts.

https://www.cyclingweekly.com/news/l...-future-193731


I have Mafacs with braze-on posts on my randonneuse and
they work
excellently with very good modulation and power; the
Racers are paired
with modern Campy Record brake levers and it is a good
combination for
me. The centerpulls offer excellent clearance for fenders
and
moderately fat tires (700 x 31). The design also allows
the brake pads
to have some clearance from the rims in case the wheel
gets slightly out
of true.

I first heard of centerpulls with brazed on posts about 40
years ago. I considered them when modifying the frame of my
old Raleigh, but went with cantilever bosses instead. But I
suspect the braze-on centerpulls would have worked about as
well.

I've not tried the direct mount brakes, but they do remove
the straddle
wire from the equation. That ought to improve efficiency,
if greater
flexibility wasn't created in the brake arms.

The straddle cable isn't a source of flexibility (if that's
what you're implying) if you shape it ahead of time to run
in a straight line from the saddle to each brake arm. Most
of the lost motion occurs because straddle cables are
naturally straight, and when installed, are bent into a
curve to reach from brake arm to saddle to brake arm. If
there's no curve, there's negligible lost motion.

Somewhere, I've seen photos of rigid links used to replace
the straddle cable. I suppose that might be even better, but
I don't know of a supplier. They might not be hard to
fabricate, if you're into that thing.

Another source of flexibility with center pulls or classic
cantilever brakes is the hanger that stops the brake
housing. Especially on front brakes, that's often a thin
steel or aluminum stamping that flexes a lot. A rigid hanger
greatly improves the brake's feel, IME.

About the website linked above, I have some agreements and
some disagreements. I agree that the chainstays are a
terrible place to mount any brake. Like the guys quoted, I
don't doubt that some of the other purported benefits (aero,
rigidity) exist, but I think the differences are likely
negligible. Especially, there are other ways to get rigidity.

But I strongly agree with the statement near the end:
"However, we think many brands that fit direct-mount brakes
at the chainstay are doing it for trend or marketing reasons."

Because, fashion! Fashion is weird and powerful.


If you pull the lever hard and observe, you'll see the
greatest loss in a CP is the brake plate- the aluminum thing
which connects the two arm pivots. Pivot bolts will visibly
move outward with even moderate lever pressure. That's
minimized with brazed posts and the other losses are
negligible by comparison.

I agree that the flex you're describing exists. Whether or not it's
the greatest source of flex depends how bad things are in the rest
of the system. My first "ten speed" (in 1972) came with Ballilla
center pull brakes. As I recall, the entire system had the rigidity
of aluminum foil.

One of my bikes came (years ago) came with a thin, stamped steel
cable housing stop, the kind with a ring that takes the place of a
threaded headset's washer, and a long arm that hung down in front.
When I squeezed the brakes, I could see it flex downward, and could
feel the brake lever move as it did.

The straightening of the straddle cable I mentioned is a bit
different, in that almost all of that slack is taken up before
significant brake force is applied. There's still a bit of give as
brake force increases from moderate to heavy (which, I think,
affects "progressiveness" during braking). But most of that
slack instead causes lost motion before much force is applied.

Returning to the pivot spread: There was a time when some companies
sold plates to connect the front end of a (front) cantilever's pivot
screws, to prevent that motion. I don't remember such a thing being
sold for center pull brakes back when they were popular, but it
would probably be more useful on that type of brake.

- Frank Krygowski

On 31/01/2020 01:55, John B. wrote:
On Thu, 30 Jan 2020 19:11:13 -0500, Frank Krygowski
wrote:

On 1/30/2020 5:18 PM, Tim McNamara wrote:
On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich
wrote:
I've been looking only at the advertisements for direct mount brakes.
...

The pictures I have seen show the cable entering the brake exactly like
a sidepull brake, but the pivots are reminiscent of Mafac Racers with
brazed-on posts.

https://www.cyclingweekly.com/news/l...-future-193731

I have Mafacs with braze-on posts on my randonneuse and they work
excellently with very good modulation and power; the Racers are paired
with modern Campy Record brake levers and it is a good combination for
me. The centerpulls offer excellent clearance for fenders and
moderately fat tires (700 x 31). The design also allows the brake pads
to have some clearance from the rims in case the wheel gets slightly out
of true.

I first heard of centerpulls with brazed on posts about 40 years ago. I
considered them when modifying the frame of my old Raleigh, but went
with cantilever bosses instead. But I suspect the braze-on centerpulls
would have worked about as well.

I've not tried the direct mount brakes, but they do remove the straddle
wire from the equation. That ought to improve efficiency, if greater
flexibility wasn't created in the brake arms.

The straddle cable isn't a source of flexibility (if that's what you're
implying) if you shape it ahead of time to run in a straight line from
the saddle to each brake arm. Most of the lost motion occurs because
straddle cables are naturally straight, and when installed, are bent
into a curve to reach from brake arm to saddle to brake arm. If there's
no curve, there's negligible lost motion.

Somewhere, I've seen photos of rigid links used to replace the straddle
cable. I suppose that might be even better, but I don't know of a
supplier. They might not be hard to fabricate, if you're into that thing.

Another source of flexibility with center pulls or classic cantilever
brakes is the hanger that stops the brake housing. Especially on front
brakes, that's often a thin steel or aluminum stamping that flexes a
lot. A rigid hanger greatly improves the brake's feel, IME.

About the website linked above, I have some agreements and some
disagreements. I agree that the chainstays are a terrible place to mount
any brake. Like the guys quoted, I don't doubt that some of the other
purported benefits (aero, rigidity) exist, but I think the differences
are likely negligible. Especially, there are other ways to get rigidity.

But I strongly agree with the statement near the end: "However, we think
many brands that fit direct-mount brakes at the chainstay are doing it
for trend or marketing reasons."

Because, fashion! Fashion is weird and powerful.

I've installed center pull, cantilever, single pivot caliper, double
pivot caliper and vee brakes on the same bike at one time or another
and it seems to me that the determining factor, brake pad composition
aside, in braking power is the ratio between the brake arm, pivot to
cable attachment, and the arm on which the brake pad is mounted,
pivot to pad mounting, i.e,, the mechanical advantage of the brake,
and in reality nothing else seems to matter. The most powerful brakes
I ever had on that bike were cheap old vee brakes which, mounted on
the previous canti lever studs, had the brake pad at the lowest
possible position on the brake arms and thus the highest mechanical
advantage between the cable attachment and the pad.

Note that brake arm length and ratio also effect the cable pull
necessary to apply the brakes and I am talking about only the
effectiveness of the brake itself. And the brake levers themselves
have a mechanical advantage that will also effect braking.

While I never installed disc brakes on that bike I have brake tested
bikes with discs and if the ability to stop the wheel from turning is
a measurement of braking efficiency then any of the more efficient rim
brakes were equal in braking efficiency to the discs.

This exactly my experience as well over various brakes. You have to go
some way to get bad braking, it's usually the setup. Well setup rim
brakes work as well as discs, but imho, there are other reasons for
moving to discs. Half of my bikes are disc, the other half lack bosses
or they would be, but not for reasons of braking power except may be in
wet, and definitely in ice, but I don't cycle in icing conditions much.

On 31/01/2020 05:35, Frank Krygowski wrote:
On Thursday, January 30, 2020 at 8:25:18 PM UTC-5, AMuzi wrote:
On 1/30/2020 6:11 PM, Frank Krygowski wrote:
On 1/30/2020 5:18 PM, Tim McNamara wrote:
On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich
wrote:
I've been looking only at the advertisements for direct
mount brakes.
...

The pictures I have seen show the cable entering the brake
exactly like
a sidepull brake, but the pivots are reminiscent of Mafac
Racers with
brazed-on posts.

https://www.cyclingweekly.com/news/l...-future-193731


I have Mafacs with braze-on posts on my randonneuse and
they work
excellently with very good modulation and power; the
Racers are paired
with modern Campy Record brake levers and it is a good
combination for
me. The centerpulls offer excellent clearance for fenders
and
moderately fat tires (700 x 31). The design also allows
the brake pads
to have some clearance from the rims in case the wheel
gets slightly out
of true.

I first heard of centerpulls with brazed on posts about 40
years ago. I considered them when modifying the frame of my
old Raleigh, but went with cantilever bosses instead. But I
suspect the braze-on centerpulls would have worked about as
well.

I've not tried the direct mount brakes, but they do remove
the straddle
wire from the equation. That ought to improve efficiency,
if greater
flexibility wasn't created in the brake arms.

The straddle cable isn't a source of flexibility (if that's
what you're implying) if you shape it ahead of time to run
in a straight line from the saddle to each brake arm. Most
of the lost motion occurs because straddle cables are
naturally straight, and when installed, are bent into a
curve to reach from brake arm to saddle to brake arm. If
there's no curve, there's negligible lost motion.

Somewhere, I've seen photos of rigid links used to replace
the straddle cable. I suppose that might be even better, but
I don't know of a supplier. They might not be hard to
fabricate, if you're into that thing.

Another source of flexibility with center pulls or classic
cantilever brakes is the hanger that stops the brake
housing. Especially on front brakes, that's often a thin
steel or aluminum stamping that flexes a lot. A rigid hanger
greatly improves the brake's feel, IME.

About the website linked above, I have some agreements and
some disagreements. I agree that the chainstays are a
terrible place to mount any brake. Like the guys quoted, I
don't doubt that some of the other purported benefits (aero,
rigidity) exist, but I think the differences are likely
negligible. Especially, there are other ways to get rigidity.

But I strongly agree with the statement near the end:
"However, we think many brands that fit direct-mount brakes
at the chainstay are doing it for trend or marketing reasons."

Because, fashion! Fashion is weird and powerful.


If you pull the lever hard and observe, you'll see the
greatest loss in a CP is the brake plate- the aluminum thing
which connects the two arm pivots. Pivot bolts will visibly
move outward with even moderate lever pressure. That's
minimized with brazed posts and the other losses are
negligible by comparison.

I agree that the flex you're describing exists. Whether or not it's
the greatest source of flex depends how bad things are in the rest
of the system. My first "ten speed" (in 1972) came with Ballilla
center pull brakes. As I recall, the entire system had the rigidity
of aluminum foil.

One of my bikes came (years ago) came with a thin, stamped steel
cable housing stop, the kind with a ring that takes the place of a
threaded headset's washer, and a long arm that hung down in front.
When I squeezed the brakes, I could see it flex downward, and could
feel the brake lever move as it did.

The straightening of the straddle cable I mentioned is a bit
different, in that almost all of that slack is taken up before
significant brake force is applied. There's still a bit of give as
brake force increases from moderate to heavy (which, I think,
affects "progressiveness" during braking). But most of that
slack instead causes lost motion before much force is applied.

Returning to the pivot spread: There was a time when some companies
sold plates to connect the front end of a (front) cantilever's pivot
screws, to prevent that motion. I don't remember such a thing being
sold for center pull brakes back when they were popular, but it
would probably be more useful on that type of brake.

These things?

https://www.google.co.uk/search?q=bi...booster+plates

On Friday, January 31, 2020 at 12:48:29 AM UTC-8, Tosspot wrote:
On 31/01/2020 05:35, Frank Krygowski wrote:
On Thursday, January 30, 2020 at 8:25:18 PM UTC-5, AMuzi wrote:
On 1/30/2020 6:11 PM, Frank Krygowski wrote:
On 1/30/2020 5:18 PM, Tim McNamara wrote:
On Wed, 29 Jan 2020 17:30:02 -0800 (PST), Tom Kunich
wrote:
I've been looking only at the advertisements for direct
mount brakes.
...

The pictures I have seen show the cable entering the brake
exactly like
a sidepull brake, but the pivots are reminiscent of Mafac
Racers with
brazed-on posts.

https://www.cyclingweekly.com/news/l...-future-193731


I have Mafacs with braze-on posts on my randonneuse and
they work
excellently with very good modulation and power; the
Racers are paired
with modern Campy Record brake levers and it is a good
combination for
me. The centerpulls offer excellent clearance for fenders
and
moderately fat tires (700 x 31). The design also allows
the brake pads
to have some clearance from the rims in case the wheel
gets slightly out
of true.

I first heard of centerpulls with brazed on posts about 40
years ago. I considered them when modifying the frame of my
old Raleigh, but went with cantilever bosses instead. But I
suspect the braze-on centerpulls would have worked about as
well.

I've not tried the direct mount brakes, but they do remove
the straddle
wire from the equation. That ought to improve efficiency,
if greater
flexibility wasn't created in the brake arms.

The straddle cable isn't a source of flexibility (if that's
what you're implying) if you shape it ahead of time to run
in a straight line from the saddle to each brake arm. Most
of the lost motion occurs because straddle cables are
naturally straight, and when installed, are bent into a
curve to reach from brake arm to saddle to brake arm. If
there's no curve, there's negligible lost motion.

Somewhere, I've seen photos of rigid links used to replace
the straddle cable. I suppose that might be even better, but
I don't know of a supplier. They might not be hard to
fabricate, if you're into that thing.

Another source of flexibility with center pulls or classic
cantilever brakes is the hanger that stops the brake
housing. Especially on front brakes, that's often a thin
steel or aluminum stamping that flexes a lot. A rigid hanger
greatly improves the brake's feel, IME.

About the website linked above, I have some agreements and
some disagreements. I agree that the chainstays are a
terrible place to mount any brake. Like the guys quoted, I
don't doubt that some of the other purported benefits (aero,
rigidity) exist, but I think the differences are likely
negligible. Especially, there are other ways to get rigidity.

But I strongly agree with the statement near the end:
"However, we think many brands that fit direct-mount brakes
at the chainstay are doing it for trend or marketing reasons."

Because, fashion! Fashion is weird and powerful.


If you pull the lever hard and observe, you'll see the
greatest loss in a CP is the brake plate- the aluminum thing
which connects the two arm pivots. Pivot bolts will visibly
move outward with even moderate lever pressure. That's
minimized with brazed posts and the other losses are
negligible by comparison.

I agree that the flex you're describing exists. Whether or not it's
the greatest source of flex depends how bad things are in the rest
of the system. My first "ten speed" (in 1972) came with Ballilla
center pull brakes. As I recall, the entire system had the rigidity
of aluminum foil.

One of my bikes came (years ago) came with a thin, stamped steel
cable housing stop, the kind with a ring that takes the place of a
threaded headset's washer, and a long arm that hung down in front.
When I squeezed the brakes, I could see it flex downward, and could
feel the brake lever move as it did.

The straightening of the straddle cable I mentioned is a bit
different, in that almost all of that slack is taken up before
significant brake force is applied. There's still a bit of give as
brake force increases from moderate to heavy (which, I think,
affects "progressiveness" during braking). But most of that
slack instead causes lost motion before much force is applied.

Returning to the pivot spread: There was a time when some companies
sold plates to connect the front end of a (front) cantilever's pivot
screws, to prevent that motion. I don't remember such a thing being
sold for center pull brakes back when they were popular, but it
would probably be more useful on that type of brake.

These things?

https://www.google.co.uk/search?q=bi...booster+plates

Yup. http://www.velo-pages.com/main.php?g...serialNumber=2 The Spence Wolf Cuptertino Bike Shrine version that was popular in the late '70s early '80s. With Scott/Mathauser brake shoes/pads. All these kludges were intended to produce braking as good as a Campy NR, begging the question of why one didn't buy NR -- or even the Shimano equivalent.

-- Jay Beattie.

On 1/31/2020 3:48 AM, Tosspot wrote:
On 31/01/2020 05:35, Frank Krygowski wrote:

Returning to the pivot spread: There was a time when some companies
sold plates to connect the front end of a (front) cantilever's pivot
screws, to prevent that motion. I don't remember such a thing being
sold for center pull brakes back when they were popular, but it
would probably be more useful on that type of brake.

These things?

https://www.google.co.uk/search?q=bi...booster+plates

Yes, those are the ones. I wonder why they were never marketed for
things like the 1970s Weinmann center pull brakes?

One possibility is that mountain bikers were frequently in situations
where they applied lots of brake force, and noticed the "spread" of the
bosses.

Another way of putting that is, despite the tales of various heroes,
most road bikers never brake really hard. So they wouldn't have made
much practical difference on road bikes.

Of course, those Weinmann brakes were used mostly back in the day when
you squeezed the levers, you came to a stop, and figured that was good.
We're now in days where every aspect of a bike's controls must exhibit
the grace and sensitivity of a fine violin. :-/


--
- Frank Krygowski

On 1/31/2020 10:21 AM, jbeattie wrote:
On Friday, January 31, 2020 at 12:48:29 AM UTC-8, Tosspot wrote:
On 31/01/2020 05:35, Frank Krygowski wrote:

Returning to the pivot spread: There was a time when some companies
sold plates to connect the front end of a (front) cantilever's pivot
screws, to prevent that motion. I don't remember such a thing being
sold for center pull brakes back when they were popular, but it
would probably be more useful on that type of brake.

These things?

https://www.google.co.uk/search?q=bi...booster+plates

Yup. http://www.velo-pages.com/main.php?g...serialNumber=2 The Spence Wolf Cuptertino Bike Shrine version that was popular in the late '70s early '80s.

Huh! I hadn't seen those.

With Scott/Mathauser brake shoes/pads. All these kludges were intended to produce braking as good as a Campy NR, begging the question of why one didn't buy NR -- or even the Shimano equivalent.
Well, then as now, people bought the brakes that were attached to the
bike when they saw it on the showroom floor.

Most people are not connoisseurs. They're more affected by advertising
copy than by finely perceived differences in performance.

(That's true even of most who claim to be connoisseurs.)

--
- Frank Krygowski

On Friday, January 31, 2020 at 8:47:13 AM UTC-8, Frank Krygowski wrote:
On 1/31/2020 10:21 AM, jbeattie wrote:
On Friday, January 31, 2020 at 12:48:29 AM UTC-8, Tosspot wrote:
On 31/01/2020 05:35, Frank Krygowski wrote:

Returning to the pivot spread: There was a time when some companies
sold plates to connect the front end of a (front) cantilever's pivot
screws, to prevent that motion. I don't remember such a thing being
sold for center pull brakes back when they were popular, but it
would probably be more useful on that type of brake.

These things?

https://www.google.co.uk/search?q=bi...booster+plates

Yup. http://www.velo-pages.com/main.php?g...serialNumber=2 The Spence Wolf Cuptertino Bike Shrine version that was popular in the late '70s early '80s.

Huh! I hadn't seen those.

With Scott/Mathauser brake shoes/pads. All these kludges were intended to produce braking as good as a Campy NR, begging the question of why one didn't buy NR -- or even the Shimano equivalent.
Well, then as now, people bought the brakes that were attached to the
bike when they saw it on the showroom floor.

Most people are not connoisseurs. They're more affected by advertising
copy than by finely perceived differences in performance.

What advertising copy? If you were buying custom-modified Mafac brakes from Spence Wolf's shop, you were a connoisseur -- albeit one who marched to a different drummer. Spence was also responsible for launching Phil Wood and one of my favorite bikes of the era, Caylor. He then went with a lot of the PNW builders -- Merz, Rodriguez, Erickson -- and Lighthouse bikes by Tim Neenan of Santa Cruz who brought us the original Stumpjumper. Spence was kind of the Gertrude Stein of bike shop owners. I don't know if he had anything on the showroom floor that was an OTC bike.

These days, just to get advertising copy, you have to be a little bit of a connoisseur and subscribe to Bicycling or VeloNews or some other bicycle publication. The only way I know about bikes is because of my son and friends who are in the business. It is much less common to buy a bare frame these days and you are tied to a lot of OE equipment -- often proprietary -- for better or mostly worse. A lot of parts are also fit only for the showroom, like wheels. They are just bike stands on mid-fi bikes and even somewhat high-end bikes. Back in the day, a nice bike had nice wheels. You can spend $4K on a bike that has disposable wheels.

-- Jay Beattie.

On 1/31/2020 12:31 PM, jbeattie wrote:
On Friday, January 31, 2020 at 8:47:13 AM UTC-8, Frank Krygowski wrote:
On 1/31/2020 10:21 AM, jbeattie wrote:
On Friday, January 31, 2020 at 12:48:29 AM UTC-8, Tosspot wrote:
On 31/01/2020 05:35, Frank Krygowski wrote:

Returning to the pivot spread: There was a time when some companies
sold plates to connect the front end of a (front) cantilever's pivot
screws, to prevent that motion. I don't remember such a thing being
sold for center pull brakes back when they were popular, but it
would probably be more useful on that type of brake.

These things?

https://www.google.co.uk/search?q=bi...booster+plates

Yup. http://www.velo-pages.com/main.php?g...serialNumber=2 The Spence Wolf Cuptertino Bike Shrine version that was popular in the late '70s early '80s.

Huh! I hadn't seen those.

With Scott/Mathauser brake shoes/pads. All these kludges were intended to produce braking as good as a Campy NR, begging the question of why one didn't buy NR -- or even the Shimano equivalent.
Well, then as now, people bought the brakes that were attached to the
bike when they saw it on the showroom floor.

Most people are not connoisseurs. They're more affected by advertising
copy than by finely perceived differences in performance.

What advertising copy? If you were buying custom-modified Mafac brakes from Spence Wolf's shop, you were a connoisseur -- albeit one who marched to a different drummer. Spence was also responsible for launching Phil Wood and one of my favorite bikes of the era, Caylor. He then went with a lot of the PNW builders -- Merz, Rodriguez, Erickson -- and Lighthouse bikes by Tim Neenan of Santa Cruz who brought us the original Stumpjumper. Spence was kind of the Gertrude Stein of bike shop owners. I don't know if he had anything on the showroom floor that was an OTC bike.

These days, just to get advertising copy, you have to be a little bit of a connoisseur and subscribe to Bicycling or VeloNews or some other bicycle publication. The only way I know about bikes is because of my son and friends who are in the business. It is much less common to buy a bare frame these days and you are tied to a lot of OE equipment -- often proprietary -- for better or mostly worse. A lot of parts are also fit only for the showroom, like wheels. They are just bike stands on mid-fi bikes and even somewhat high-end bikes. Back in the day, a nice bike had nice wheels. You can spend $4K on a bike that has disposable wheels.

"What advertising copy?" Sheesh! The advertising copy that got them to
look at the Trek, or Giant, or whatever bike they lusted after in the shop!

IOW, you missed my point entirely. First, most people did not go into
shops looking for customized Mafac brakes. Most people never heard of
Mafac brakes. Most people (assuming they wanted something fancier than a
Huffy) went into a Schwinn shop, and the sophisticated ones went into a
Raleigh shop. They looked at the in-store catalogs and saw "Powerful
centerpull brakes!" and thought "Gosh, those centerpull brakes sure are
powerful." A few of them even wandered in here and said "Centerpull
brakes are more powerful than sidepulls" and got reamed by Jobst. Remember?

By and large, people buy what they're told to buy. Today people are told
"disc brakes are SO much safer!" in part because manufacturers are
putting disc brakes on so many bikes. So people who never had a problem
with any caliper brake won't buy a bike without disc brakes.

But the industry survives on churning. Perhaps the next churn will be
direct mount brakes. Maybe _Buycycling_ reviews (ghost-written by
manufacturers?) will begin saying "Direct mounts stop just as well and
are lighter and more aerodynamic." Maybe articles will snark about noise
and short disc pad life and bent rotors. Maybe touring articles will
talk about being stranded in the Himalayas and having to re-bleed discs
using only yak spit. And manufacturer's catalogs will say "Sleek,
aerodynamic direct pull brakes!"

If that's the way it goes, people will wander into shops and say "You
mean _all_ your bikes have _discs_?? This is 2023!!!"

--
- Frank Krygowski

On Fri, 31 Jan 2020 09:31:04 -0800 (PST), jbeattie
wrote:

Spence was kind of the Gertrude Stein of bike shop owners.

OM effing' G, that was frickin' hilarious!

On Friday, January 31, 2020 at 11:47:53 AM UTC-8, Frank Krygowski wrote:
On 1/31/2020 12:31 PM, jbeattie wrote:
On Friday, January 31, 2020 at 8:47:13 AM UTC-8, Frank Krygowski wrote:
On 1/31/2020 10:21 AM, jbeattie wrote:
On Friday, January 31, 2020 at 12:48:29 AM UTC-8, Tosspot wrote:
On 31/01/2020 05:35, Frank Krygowski wrote:

Returning to the pivot spread: There was a time when some companies
sold plates to connect the front end of a (front) cantilever's pivot
screws, to prevent that motion. I don't remember such a thing being
sold for center pull brakes back when they were popular, but it
would probably be more useful on that type of brake.

These things?

https://www.google.co.uk/search?q=bi...booster+plates

Yup. http://www.velo-pages.com/main.php?g...serialNumber=2 The Spence Wolf Cuptertino Bike Shrine version that was popular in the late '70s early '80s.

Huh! I hadn't seen those.

With Scott/Mathauser brake shoes/pads. All these kludges were intended to produce braking as good as a Campy NR, begging the question of why one didn't buy NR -- or even the Shimano equivalent.
Well, then as now, people bought the brakes that were attached to the
bike when they saw it on the showroom floor.

Most people are not connoisseurs. They're more affected by advertising
copy than by finely perceived differences in performance.

What advertising copy? If you were buying custom-modified Mafac brakes from Spence Wolf's shop, you were a connoisseur -- albeit one who marched to a different drummer. Spence was also responsible for launching Phil Wood and one of my favorite bikes of the era, Caylor. He then went with a lot of the PNW builders -- Merz, Rodriguez, Erickson -- and Lighthouse bikes by Tim Neenan of Santa Cruz who brought us the original Stumpjumper. Spence was kind of the Gertrude Stein of bike shop owners. I don't know if he had anything on the showroom floor that was an OTC bike.

These days, just to get advertising copy, you have to be a little bit of a connoisseur and subscribe to Bicycling or VeloNews or some other bicycle publication. The only way I know about bikes is because of my son and friends who are in the business. It is much less common to buy a bare frame these days and you are tied to a lot of OE equipment -- often proprietary -- for better or mostly worse. A lot of parts are also fit only for the showroom, like wheels. They are just bike stands on mid-fi bikes and even somewhat high-end bikes. Back in the day, a nice bike had nice wheels. You can spend $4K on a bike that has disposable wheels.

"What advertising copy?" Sheesh! The advertising copy that got them to
look at the Trek, or Giant, or whatever bike they lusted after in the shop!

IOW, you missed my point entirely. First, most people did not go into
shops looking for customized Mafac brakes. Most people never heard of
Mafac brakes. Most people (assuming they wanted something fancier than a
Huffy) went into a Schwinn shop, and the sophisticated ones went into a
Raleigh shop. They looked at the in-store catalogs and saw "Powerful
centerpull brakes!" and thought "Gosh, those centerpull brakes sure are
powerful." A few of them even wandered in here and said "Centerpull
brakes are more powerful than sidepulls" and got reamed by Jobst. Remember?

By and large, people buy what they're told to buy. Today people are told
"disc brakes are SO much safer!" in part because manufacturers are
putting disc brakes on so many bikes. So people who never had a problem
with any caliper brake won't buy a bike without disc brakes.

But the industry survives on churning. Perhaps the next churn will be
direct mount brakes. Maybe _Buycycling_ reviews (ghost-written by
manufacturers?) will begin saying "Direct mounts stop just as well and
are lighter and more aerodynamic." Maybe articles will snark about noise
and short disc pad life and bent rotors. Maybe touring articles will
talk about being stranded in the Himalayas and having to re-bleed discs
using only yak spit. And manufacturer's catalogs will say "Sleek,
aerodynamic direct pull brakes!"

If that's the way it goes, people will wander into shops and say "You
mean _all_ your bikes have _discs_?? This is 2023!!!"

--
- Frank Krygowski

Jay likes to fly with the best equipment. Anything wrong with that? I felt disk brakes to be dangerously strong in that you could unknowingly put them on FAR too hard and got over the top of the bike. So I'm not wild about them.

I think originally it was an attempt to improve braking for the pro's but it sure as hell didn't and it had a lot of added drag and weight. They seemed to have improved that with the 140 mm disks and the flat mounts for the actuators but the only thing I believe them to be good for is prolonging the life of the wheel rims.

Since the pro's get a new bike or 5 every year I don't know that it matters how long the wheels last. They are bought new every year if you don't have a wheel sponsor.

One of the things I didn't like is that you had to set the rim brakes up with a slight forward bias so that when you applied the brakes the bending of the mounting shaft would bring the brake shoes into direct flat contact.

With the direct mount brakes there isn't hardly any flex so you can mount the brakes so they start with a full brake shoe contact on the rims. No shudder and no excessive wear on the brake path on the rim from that shuttering..

BUT in either case if you buy up you have to get special brakes one way or the other. And it won't be long before all of the over-the-counter bikes have one type or the other and the center-mounts will disappear.