Road Discs

John B. wrote:
On Mon, 25 Sep 2017 08:48:53 -0700 (PDT), Sir Ridesalot
wrote:

On Monday, September 25, 2017 at 11:35:45 AM UTC-4, jbeattie wrote:
On Monday, September 25, 2017 at 7:55:26 AM UTC-7, Frank Krygowski wrote:
Snipped
I have tried some, which is why I'm concerned! Granted, I haven't done long
rides on any. My tests were on bikes belonging to friends, one bike I was
fixing for a bike tourist we were hosting, bikes I tested briefly while
helping a good friend shop for a new bike, and a mountain bike owned by an
acquaintance who let me ride it for maybe half an hour in our local forest
preserve.

The latter was the most upscale bike of the lot. When he traded bikes with me,
he cautioned me "Don't forget, you never need more than one finger on the
brakes." He was right, of course. And I'd be unlikely to forget on that
bike because it had undersized brake levers, plus it was way different than any
of my bikes. But on a road bike with normal sized levers, I'd worry about
forgetting.

I once saw a woman go over the bars because she wasn't familiar with the
reduced lever force of Shimano dual pivots, back when those were new technology.

It seems to me that stopping a bike hard should require a bit of a hard squeeze
on the levers. At least, until bicycles come with something vaguely akin to the
anti-lock brakes on cars. (Anti-pitchover brakes?)

I don't think front discs are a problem for most normal people coming
from a dual pivot or other efficient brake. Rear hydraulic discs do
require some adjustment because they are far more powerful than any
cable operated brake, being that there aren't the usual losses from
cable or housing. I was skidding my rear on the Roubaix, but that
hasn't been an issue on the Norco for some reason. Maybe I'm
acclimated -- or maybe the Roubaix had too much system pressure. The
rear cable disc is no better than a rim brake in dry weather. A rear
dual pivot is actually stronger, but I hope to remedy that problem with
a new rear brake. The first generation Avid BB7s (mine are 13 years
old) had crappy return springs that can't manage all the cable drag,
and the caliper will rub after braking if the pads are set close to the disc.

-- Jay Beattie.

I can easily apply my front Dura Ace AX brake to a force where the rear
wheel lifts a lot and I have to release the front brake lever to avoid going over the bar.

On my MTB with the roller cam rear brake under the chainstays, I can
easily lock up the rear wheel in ant weather = dry or wet.

Cheers

Given that the braking force of a wheeled vehicle is a factor of the
coefficient of friction between the tires and the road I am at a bit
of a loss as to why a disk brake is so much superior to a rim brake as
with vee brakes I can easily skid either the front wheel (very
carefully :-) or the rear wheel, or both wheels together on ordinary
black asphalt pavement, either dry or wet, using two fingers on the
brake lever.

Will disk brakes somehow magically improve this.
--
Cheers,

John B.



I don’t think the question is stopping on wet pavement. I think the
question is stopping with wet rims and pads. I don’t use disc brakes and
generally don’t need them but I’ve recently been caught in a heavy downpour
where my brakes didn’t stop well.

Jay commutes in a hilly, rainy area and says disc brakes work when wet. I
expect he knows what he’s talking about.

--
duane

On Sunday, September 10, 2017 at 12:28:59 AM UTC+2, jbeattie wrote:
So, my SuperSix was crushed in a roof-rack accident and last weak my Roubaix was stolen out of the garage that I left open all night. I've done that many times -- apparently one too many. I'm down to a gravel bike and my commuter -- the reborn warranty CAADX (which is a great bike).

The gravel bike is a pig, but I'll use that for fall/winter/spring sport riding. I want a fast bike, though -- and I've got a line on a nice bike that I can get with rim brakes or discs, but the disc model will not be available until December -- which really means that I get to ride it in dry weather some time around May. I can get a rim brake model by the end of the month.

All the shops are pushing discs, and I did like the discs on the Roubaix and on my gravel bike. I know this is absolutely the wrong group to ask because it's wall-to-wall curmudgeons, but if you were buying your last nice road bike, would you go rim brakes or discs? It will be a dry weather bike or ridden in the rain only because of bad luck. There would be no real weight penalty because the bike is so light to start with. I'm not aero, so I don't care about the aero penalty with discs.

My concern with getting rim brakes is not really even a performance issue because in dry weather, I've never had a problem with rim brakes -- but to listen to the guys at the local shop, rim brakes are going the way of the dodo. I'm worried about buying an antique!

-- Jay Beattie.

Of course Jay knows what he is talking about. The people saying that they can skid their wheels with whatever brakes they use don't get it. I don't want my wheels to skid, I want to slow down in a controlled and predictable manner in all circumstances. In dry conditions, flat terrain and no CF rims any brake system will do.

Lou

On Tuesday, September 26, 2017 at 2:56:47 AM UTC-7, Duane wrote:
John B. wrote:
On Mon, 25 Sep 2017 08:48:53 -0700 (PDT), Sir Ridesalot
wrote:

On Monday, September 25, 2017 at 11:35:45 AM UTC-4, jbeattie wrote:
On Monday, September 25, 2017 at 7:55:26 AM UTC-7, Frank Krygowski wrote:
Snipped
I have tried some, which is why I'm concerned! Granted, I haven't done long
rides on any. My tests were on bikes belonging to friends, one bike I was
fixing for a bike tourist we were hosting, bikes I tested briefly while
helping a good friend shop for a new bike, and a mountain bike owned by an
acquaintance who let me ride it for maybe half an hour in our local forest
preserve.

The latter was the most upscale bike of the lot. When he traded bikes with me,
he cautioned me "Don't forget, you never need more than one finger on the
brakes." He was right, of course. And I'd be unlikely to forget on that
bike because it had undersized brake levers, plus it was way different than any
of my bikes. But on a road bike with normal sized levers, I'd worry about
forgetting.

I once saw a woman go over the bars because she wasn't familiar with the
reduced lever force of Shimano dual pivots, back when those were new technology.

It seems to me that stopping a bike hard should require a bit of a hard squeeze
on the levers. At least, until bicycles come with something vaguely akin to the
anti-lock brakes on cars. (Anti-pitchover brakes?)

I don't think front discs are a problem for most normal people coming
from a dual pivot or other efficient brake. Rear hydraulic discs do
require some adjustment because they are far more powerful than any
cable operated brake, being that there aren't the usual losses from
cable or housing. I was skidding my rear on the Roubaix, but that
hasn't been an issue on the Norco for some reason. Maybe I'm
acclimated -- or maybe the Roubaix had too much system pressure. The
rear cable disc is no better than a rim brake in dry weather. A rear
dual pivot is actually stronger, but I hope to remedy that problem with
a new rear brake. The first generation Avid BB7s (mine are 13 years
old) had crappy return springs that can't manage all the cable drag,
and the caliper will rub after braking if the pads are set close to the disc.

-- Jay Beattie.

I can easily apply my front Dura Ace AX brake to a force where the rear
wheel lifts a lot and I have to release the front brake lever to avoid going over the bar.

On my MTB with the roller cam rear brake under the chainstays, I can
easily lock up the rear wheel in ant weather = dry or wet.

Cheers

Given that the braking force of a wheeled vehicle is a factor of the
coefficient of friction between the tires and the road I am at a bit
of a loss as to why a disk brake is so much superior to a rim brake as
with vee brakes I can easily skid either the front wheel (very
carefully :-) or the rear wheel, or both wheels together on ordinary
black asphalt pavement, either dry or wet, using two fingers on the
brake lever.

Will disk brakes somehow magically improve this.
--
Cheers,

John B.



I don’t think the question is stopping on wet pavement. I think the
question is stopping with wet rims and pads. I don’t use disc brakes and
generally don’t need them but I’ve recently been caught in a heavy downpour
where my brakes didn’t stop well.

Jay commutes in a hilly, rainy area and says disc brakes work when wet. I
expect he knows what he’s talking about.

I certainly know what I like. A good dual pivot will stop you in the rain, although you may get a little free-fall before braking starts. My issue was the brake-lathe effect in wet weather. One of my work cohorts commutes year round, mostly flat and farther than I do on a daily basis. He was replacing his front rim every year to two years. He finally got tired of paying for rim swaps and bought an on-sale Fuji with cable discs.

Braking is also more rapid and positive with a well adjusted disc. A poorly adjusted cable disc is worse than a dual pivot, which is an argument for hydraulic discs on wet weather bikes. I really like the way the hydraulic discs modulate on the Norco. The rear brake was too powerful on the stolen Roubaix, and I had to get used to that -- although it did seem to relax over time, maybe due to pad wear-in. Anyway, there are pros and cons, but I wouldn't build a year-round wet weather commuter or CX/gravel bike with rim brakes. On a road race bike, I would (and did) go with rim brakes, although hydraulic discs are still a reasonable choice and a good choice on a bike with CF rims that will be raced in spring classics. My nice bike will only get wet because I didn't plan well -- and poor braking will be my penance.

-- Jay Beattie.

On Tuesday, September 26, 2017 at 7:18:33 AM UTC-7, jbeattie wrote:
On Tuesday, September 26, 2017 at 2:56:47 AM UTC-7, Duane wrote:
John B. wrote:
On Mon, 25 Sep 2017 08:48:53 -0700 (PDT), Sir Ridesalot
wrote:

On Monday, September 25, 2017 at 11:35:45 AM UTC-4, jbeattie wrote:
On Monday, September 25, 2017 at 7:55:26 AM UTC-7, Frank Krygowski wrote:
Snipped
I have tried some, which is why I'm concerned! Granted, I haven't done long
rides on any. My tests were on bikes belonging to friends, one bike I was
fixing for a bike tourist we were hosting, bikes I tested briefly while
helping a good friend shop for a new bike, and a mountain bike owned by an
acquaintance who let me ride it for maybe half an hour in our local forest
preserve.

The latter was the most upscale bike of the lot. When he traded bikes with me,
he cautioned me "Don't forget, you never need more than one finger on the
brakes." He was right, of course. And I'd be unlikely to forget on that
bike because it had undersized brake levers, plus it was way different than any
of my bikes. But on a road bike with normal sized levers, I'd worry about
forgetting.

I once saw a woman go over the bars because she wasn't familiar with the
reduced lever force of Shimano dual pivots, back when those were new technology.

It seems to me that stopping a bike hard should require a bit of a hard squeeze
on the levers. At least, until bicycles come with something vaguely akin to the
anti-lock brakes on cars. (Anti-pitchover brakes?)

I don't think front discs are a problem for most normal people coming
from a dual pivot or other efficient brake. Rear hydraulic discs do
require some adjustment because they are far more powerful than any
cable operated brake, being that there aren't the usual losses from
cable or housing. I was skidding my rear on the Roubaix, but that
hasn't been an issue on the Norco for some reason. Maybe I'm
acclimated -- or maybe the Roubaix had too much system pressure. The
rear cable disc is no better than a rim brake in dry weather. A rear
dual pivot is actually stronger, but I hope to remedy that problem with
a new rear brake. The first generation Avid BB7s (mine are 13 years
old) had crappy return springs that can't manage all the cable drag,
and the caliper will rub after braking if the pads are set close to the disc.

-- Jay Beattie.

I can easily apply my front Dura Ace AX brake to a force where the rear
wheel lifts a lot and I have to release the front brake lever to avoid going over the bar.

On my MTB with the roller cam rear brake under the chainstays, I can
easily lock up the rear wheel in ant weather = dry or wet.

Cheers

Given that the braking force of a wheeled vehicle is a factor of the
coefficient of friction between the tires and the road I am at a bit
of a loss as to why a disk brake is so much superior to a rim brake as
with vee brakes I can easily skid either the front wheel (very
carefully :-) or the rear wheel, or both wheels together on ordinary
black asphalt pavement, either dry or wet, using two fingers on the
brake lever.

Will disk brakes somehow magically improve this.
--
Cheers,

John B.



I don’t think the question is stopping on wet pavement. I think the
question is stopping with wet rims and pads. I don’t use disc brakes and
generally don’t need them but I’ve recently been caught in a heavy downpour
where my brakes didn’t stop well.

Jay commutes in a hilly, rainy area and says disc brakes work when wet. I
expect he knows what he’s talking about.

I certainly know what I like. A good dual pivot will stop you in the rain, although you may get a little free-fall before braking starts. My issue was the brake-lathe effect in wet weather. One of my work cohorts commutes year round, mostly flat and farther than I do on a daily basis. He was replacing his front rim every year to two years. He finally got tired of paying for rim swaps and bought an on-sale Fuji with cable discs.

Braking is also more rapid and positive with a well adjusted disc. A poorly adjusted cable disc is worse than a dual pivot, which is an argument for hydraulic discs on wet weather bikes. I really like the way the hydraulic discs modulate on the Norco. The rear brake was too powerful on the stolen Roubaix, and I had to get used to that -- although it did seem to relax over time, maybe due to pad wear-in. Anyway, there are pros and cons, but I wouldn't build a year-round wet weather commuter or CX/gravel bike with rim brakes. On a road race bike, I would (and did) go with rim brakes, although hydraulic discs are still a reasonable choice and a good choice on a bike with CF rims that will be raced in spring classics. My nice bike will only get wet because I didn't plan well -- and poor braking will be my penance.

-- Jay Beattie.

You know, I've used all brakes in all sorts of conditions and I sure as hell never had "free fall" since all it takes is to drag your brakes a little before you require them. Do you really ride bikes?

I am getting the idea that this group is a bunch of people who used to ride bikes 10 or more years ago. Joerg and Lou seems to be the only ones that know what's going on.

On 9/26/2017 4:38 AM, James wrote:
On 26/09/17 13:06, Frank Krygowski wrote:
On 9/25/2017 6:00 PM, jbeattie wrote:
Â*People are willing to accept the weight and aerodynamic penalty with
discs, apparently on the belief that ordinary rim brakes are
inadequate or because they want to use CF wheels. Who knows.

Many people are willing to accept anything that's in fashion in their
own little world. Fashion is amazingly powerful, and doesn't need to
make any particular sense.

At least we can claim that disc brakes are marginally more useful than
tattoos.


If a person wants to use wheels with CFRP rims, a bike with disc brakes
makes sense.

CFRP rims with rim brakes usually work ok in dry conditions provided the
correct brake blocks are used.Â* Some CFRP rims can be damaged if the
wrong pads are used, and some have been damaged even with the "correct"
pads.

But in wet conditions, the braking performance is generally very much
worse.

Disc brakes solve those problems, and allow rim manufacturers to save
more grams because there's no need for a braking surface.

I'm not saying there are never benefits to disc brakes, and I don't
think anyone else is saying that.

I would never tell Jay he shouldn't use discs; his commuting regimen in
hilly, rainy Portland is perfect for them.

So yes, discs have some advantages. They also have some disadvantages,
and those disadvantages become known only through discussions something
like this one. Advertisers are certainly not going to spend much time
listing the disadvantages.

And the typical consumer isn't going to think about these things at all,
beyond "Oooh, disc brakes. They use them on motorcycles, so that's what
I need! I'll never buy a bike without them things!"

We're supposed to be better than that. We should consider both
advantages and disadvantages. It happens to be my judgment that for
almost all road cyclists, the disadvantages outweigh the advantages.
Almost everyone would be better off with more normal brakes.

--
- Frank Krygowski

On 9/26/2017 8:11 AM, wrote:


Of course Jay knows what he is talking about. The people saying that they can skid their wheels with whatever brakes they use don't get it. I don't want my wheels to skid, I want to slow down in a controlled and predictable manner in all circumstances. In dry conditions, flat terrain and no CF rims any brake system will do.

Have you had problems in dry conditions in hilly terrain? So far I haven't.


--
- Frank Krygowski

On Tuesday, September 26, 2017 at 10:33:21 AM UTC-7, wrote:
On Tuesday, September 26, 2017 at 7:18:33 AM UTC-7, jbeattie wrote:
On Tuesday, September 26, 2017 at 2:56:47 AM UTC-7, Duane wrote:
John B. wrote:
On Mon, 25 Sep 2017 08:48:53 -0700 (PDT), Sir Ridesalot
wrote:

On Monday, September 25, 2017 at 11:35:45 AM UTC-4, jbeattie wrote:
On Monday, September 25, 2017 at 7:55:26 AM UTC-7, Frank Krygowski wrote:
Snipped
I have tried some, which is why I'm concerned! Granted, I haven't done long
rides on any. My tests were on bikes belonging to friends, one bike I was
fixing for a bike tourist we were hosting, bikes I tested briefly while
helping a good friend shop for a new bike, and a mountain bike owned by an
acquaintance who let me ride it for maybe half an hour in our local forest
preserve.

The latter was the most upscale bike of the lot. When he traded bikes with me,
he cautioned me "Don't forget, you never need more than one finger on the
brakes." He was right, of course. And I'd be unlikely to forget on that
bike because it had undersized brake levers, plus it was way different than any
of my bikes. But on a road bike with normal sized levers, I'd worry about
forgetting.

I once saw a woman go over the bars because she wasn't familiar with the
reduced lever force of Shimano dual pivots, back when those were new technology.

It seems to me that stopping a bike hard should require a bit of a hard squeeze
on the levers. At least, until bicycles come with something vaguely akin to the
anti-lock brakes on cars. (Anti-pitchover brakes?)

I don't think front discs are a problem for most normal people coming
from a dual pivot or other efficient brake. Rear hydraulic discs do
require some adjustment because they are far more powerful than any
cable operated brake, being that there aren't the usual losses from
cable or housing. I was skidding my rear on the Roubaix, but that
hasn't been an issue on the Norco for some reason. Maybe I'm
acclimated -- or maybe the Roubaix had too much system pressure. The
rear cable disc is no better than a rim brake in dry weather. A rear
dual pivot is actually stronger, but I hope to remedy that problem with
a new rear brake. The first generation Avid BB7s (mine are 13 years
old) had crappy return springs that can't manage all the cable drag,
and the caliper will rub after braking if the pads are set close to the disc.

-- Jay Beattie.

I can easily apply my front Dura Ace AX brake to a force where the rear
wheel lifts a lot and I have to release the front brake lever to avoid going over the bar.

On my MTB with the roller cam rear brake under the chainstays, I can
easily lock up the rear wheel in ant weather = dry or wet.

Cheers

Given that the braking force of a wheeled vehicle is a factor of the
coefficient of friction between the tires and the road I am at a bit
of a loss as to why a disk brake is so much superior to a rim brake as
with vee brakes I can easily skid either the front wheel (very
carefully :-) or the rear wheel, or both wheels together on ordinary
black asphalt pavement, either dry or wet, using two fingers on the
brake lever.

Will disk brakes somehow magically improve this.
--
Cheers,

John B.



I don’t think the question is stopping on wet pavement. I think the
question is stopping with wet rims and pads. I don’t use disc brakes and
generally don’t need them but I’ve recently been caught in a heavy downpour
where my brakes didn’t stop well.

Jay commutes in a hilly, rainy area and says disc brakes work when wet. I
expect he knows what he’s talking about.

I certainly know what I like. A good dual pivot will stop you in the rain, although you may get a little free-fall before braking starts. My issue was the brake-lathe effect in wet weather. One of my work cohorts commutes year round, mostly flat and farther than I do on a daily basis. He was replacing his front rim every year to two years. He finally got tired of paying for rim swaps and bought an on-sale Fuji with cable discs.

Braking is also more rapid and positive with a well adjusted disc. A poorly adjusted cable disc is worse than a dual pivot, which is an argument for hydraulic discs on wet weather bikes. I really like the way the hydraulic discs modulate on the Norco. The rear brake was too powerful on the stolen Roubaix, and I had to get used to that -- although it did seem to relax over time, maybe due to pad wear-in. Anyway, there are pros and cons, but I wouldn't build a year-round wet weather commuter or CX/gravel bike with rim brakes. On a road race bike, I would (and did) go with rim brakes, although hydraulic discs are still a reasonable choice and a good choice on a bike with CF rims that will be raced in spring classics. My nice bike will only get wet because I didn't plan well -- and poor braking will be my penance.

-- Jay Beattie.

You know, I've used all brakes in all sorts of conditions and I sure as hell never had "free fall" since all it takes is to drag your brakes a little before you require them. Do you really ride bikes?

I can guaranty you that I have ridden in the rain more than you. I've ridden most every day for the last 50 years, 33 of those in Portland -- year round, in snow and ice, too. Well, not so much ice anymore. You probably don't see this much in Oakland: https://www.youtube.com/watch?v=jo-XnPJRJVg
https://www.youtube.com/watch?v=p31FqlkSPXs

When I'm coming down out of the West Hills in heavy rain (10-20% descents on broken pavement), I can get a free fall effect when first applying the brakes. You don't always drag brakes, and one revolution picks up a whole new wheel full of water, so there will always have an initial braking effort -- light or hard, and a lag time between effort and any stopping at all. That lag feels like free fall because you're squeezing the brakes and nothing is happening. YMMV.

-- Jay Beattie.

On 26/09/2017 2:39 PM, jbeattie wrote:
On Tuesday, September 26, 2017 at 10:33:21 AM UTC-7, wrote:
On Tuesday, September 26, 2017 at 7:18:33 AM UTC-7, jbeattie wrote:
On Tuesday, September 26, 2017 at 2:56:47 AM UTC-7, Duane wrote:
John B. wrote:
On Mon, 25 Sep 2017 08:48:53 -0700 (PDT), Sir Ridesalot
wrote:

On Monday, September 25, 2017 at 11:35:45 AM UTC-4, jbeattie wrote:
On Monday, September 25, 2017 at 7:55:26 AM UTC-7, Frank Krygowski wrote:
Snipped
I have tried some, which is why I'm concerned! Granted, I haven't done long
rides on any. My tests were on bikes belonging to friends, one bike I was
fixing for a bike tourist we were hosting, bikes I tested briefly while
helping a good friend shop for a new bike, and a mountain bike owned by an
acquaintance who let me ride it for maybe half an hour in our local forest
preserve.

The latter was the most upscale bike of the lot. When he traded bikes with me,
he cautioned me "Don't forget, you never need more than one finger on the
brakes." He was right, of course. And I'd be unlikely to forget on that
bike because it had undersized brake levers, plus it was way different than any
of my bikes. But on a road bike with normal sized levers, I'd worry about
forgetting.

I once saw a woman go over the bars because she wasn't familiar with the
reduced lever force of Shimano dual pivots, back when those were new technology.

It seems to me that stopping a bike hard should require a bit of a hard squeeze
on the levers. At least, until bicycles come with something vaguely akin to the
anti-lock brakes on cars. (Anti-pitchover brakes?)

I don't think front discs are a problem for most normal people coming
from a dual pivot or other efficient brake. Rear hydraulic discs do
require some adjustment because they are far more powerful than any
cable operated brake, being that there aren't the usual losses from
cable or housing. I was skidding my rear on the Roubaix, but that
hasn't been an issue on the Norco for some reason. Maybe I'm
acclimated -- or maybe the Roubaix had too much system pressure. The
rear cable disc is no better than a rim brake in dry weather. A rear
dual pivot is actually stronger, but I hope to remedy that problem with
a new rear brake. The first generation Avid BB7s (mine are 13 years
old) had crappy return springs that can't manage all the cable drag,
and the caliper will rub after braking if the pads are set close to the disc.

-- Jay Beattie.

I can easily apply my front Dura Ace AX brake to a force where the rear
wheel lifts a lot and I have to release the front brake lever to avoid going over the bar.

On my MTB with the roller cam rear brake under the chainstays, I can
easily lock up the rear wheel in ant weather = dry or wet.

Cheers

Given that the braking force of a wheeled vehicle is a factor of the
coefficient of friction between the tires and the road I am at a bit
of a loss as to why a disk brake is so much superior to a rim brake as
with vee brakes I can easily skid either the front wheel (very
carefully :-) or the rear wheel, or both wheels together on ordinary
black asphalt pavement, either dry or wet, using two fingers on the
brake lever.

Will disk brakes somehow magically improve this.
--
Cheers,

John B.



I don’t think the question is stopping on wet pavement. I think the
question is stopping with wet rims and pads. I don’t use disc brakes and
generally don’t need them but I’ve recently been caught in a heavy downpour
where my brakes didn’t stop well.

Jay commutes in a hilly, rainy area and says disc brakes work when wet. I
expect he knows what he’s talking about.

I certainly know what I like. A good dual pivot will stop you in the rain, although you may get a little free-fall before braking starts. My issue was the brake-lathe effect in wet weather. One of my work cohorts commutes year round, mostly flat and farther than I do on a daily basis. He was replacing his front rim every year to two years. He finally got tired of paying for rim swaps and bought an on-sale Fuji with cable discs.

Braking is also more rapid and positive with a well adjusted disc. A poorly adjusted cable disc is worse than a dual pivot, which is an argument for hydraulic discs on wet weather bikes. I really like the way the hydraulic discs modulate on the Norco. The rear brake was too powerful on the stolen Roubaix, and I had to get used to that -- although it did seem to relax over time, maybe due to pad wear-in. Anyway, there are pros and cons, but I wouldn't build a year-round wet weather commuter or CX/gravel bike with rim brakes. On a road race bike, I would (and did) go with rim brakes, although hydraulic discs are still a reasonable choice and a good choice on a bike with CF rims that will be raced in spring classics. My nice bike will only get wet because I didn't plan well -- and poor braking will be my penance.

-- Jay Beattie.

You know, I've used all brakes in all sorts of conditions and I sure as hell never had "free fall" since all it takes is to drag your brakes a little before you require them. Do you really ride bikes?

I can guaranty you that I have ridden in the rain more than you. I've ridden most every day for the last 50 years, 33 of those in Portland -- year round, in snow and ice, too. Well, not so much ice anymore. You probably don't see this much in Oakland: https://www.youtube.com/watch?v=jo-XnPJRJVg
https://www.youtube.com/watch?v=p31FqlkSPXs

When I'm coming down out of the West Hills in heavy rain (10-20% descents on broken pavement), I can get a free fall effect when first applying the brakes. You don't always drag brakes, and one revolution picks up a whole new wheel full of water, so there will always have an initial braking effort -- light or hard, and a lag time between effort and any stopping at all. That lag feels like free fall because you're squeezing the brakes and nothing is happening. YMMV.


I can tell you that when I got caught in the thunderstorm last June, it
took some distance to stop and with the low visibility, traffic and the
lightning it was not a pleasant experience. I'm not sure I'd call it
freefall but it was like I had no brakes. This was on relatively flat
ground. We all had pretty much the same experience and ended up finding
shelter until it slacked up.

On Monday, September 25, 2017 at 6:44:56 PM UTC-7, John B. wrote:
On Mon, 25 Sep 2017 08:48:53 -0700 (PDT), Sir Ridesalot
wrote:

On Monday, September 25, 2017 at 11:35:45 AM UTC-4, jbeattie wrote:
On Monday, September 25, 2017 at 7:55:26 AM UTC-7, Frank Krygowski wrote:
Snipped
I have tried some, which is why I'm concerned! Granted, I haven't done long
rides on any. My tests were on bikes belonging to friends, one bike I was
fixing for a bike tourist we were hosting, bikes I tested briefly while
helping a good friend shop for a new bike, and a mountain bike owned by an
acquaintance who let me ride it for maybe half an hour in our local forest
preserve.

The latter was the most upscale bike of the lot. When he traded bikes with me,
he cautioned me "Don't forget, you never need more than one finger on the
brakes." He was right, of course. And I'd be unlikely to forget on that
bike because it had undersized brake levers, plus it was way different than any
of my bikes. But on a road bike with normal sized levers, I'd worry about
forgetting.

I once saw a woman go over the bars because she wasn't familiar with the
reduced lever force of Shimano dual pivots, back when those were new technology.

It seems to me that stopping a bike hard should require a bit of a hard squeeze
on the levers. At least, until bicycles come with something vaguely akin to the
anti-lock brakes on cars. (Anti-pitchover brakes?)

I don't think front discs are a problem for most normal people coming from a dual pivot or other efficient brake. Rear hydraulic discs do require some adjustment because they are far more powerful than any cable operated brake, being that there aren't the usual losses from cable or housing. I was skidding my rear on the Roubaix, but that hasn't been an issue on the Norco for some reason. Maybe I'm acclimated -- or maybe the Roubaix had too much system pressure. The rear cable disc is no better than a rim brake in dry weather. A rear dual pivot is actually stronger, but I hope to remedy that problem with a new rear brake. The first generation Avid BB7s (mine are 13 years old) had crappy return springs that can't manage all the cable drag, and the caliper will rub after braking if the pads are set close to the disc.

-- Jay Beattie.

I can easily apply my front Dura Ace AX brake to a force where the rear wheel lifts a lot and I have to release the front brake lever to avoid going over the bar.

On my MTB with the roller cam rear brake under the chainstays, I can easily lock up the rear wheel in ant weather = dry or wet.

Cheers

Given that the braking force of a wheeled vehicle is a factor of the
coefficient of friction between the tires and the road I am at a bit
of a loss as to why a disk brake is so much superior to a rim brake as
with vee brakes I can easily skid either the front wheel (very
carefully :-) or the rear wheel, or both wheels together on ordinary
black asphalt pavement, either dry or wet, using two fingers on the
brake lever.

Will disk brakes somehow magically improve this.

Not until you state it correctly.

On Tuesday, September 26, 2017 at 8:10:04 PM UTC+2, Frank Krygowski wrote:
On 9/26/2017 8:11 AM, wrote:


Of course Jay knows what he is talking about. The people saying that they can skid their wheels with whatever brakes they use don't get it. I don't want my wheels to skid, I want to slow down in a controlled and predictable manner in all circumstances. In dry conditions, flat terrain and no CF rims any brake system will do.

Have you had problems in dry conditions in hilly terrain? So far I haven't.


--
- Frank Krygowski

Huh, where did I said that? Fyi, all my road bikes have rimbrakes. Always had. Only my FS mountainbike and my cross bike have hydraulic disk brakes. So I know the advantages and disadvantages of both. Do you, by own experience or only from heresay?

Lou