disc brakes for road bikes?

Stefan said:

I was chatting with my riding buddies this last weekend and we started
a discussion on why road bike companies have not adopted disc brakes
for road bikes? It seems to me that the greater stopping power would
be a good idea, especially for hilly riding.
I'm curious as to what you all think? Should road bike disc brakes be
created and how come they don't exist today?

Disc specific forks are available for road bikes - I saw a number of
cyclo-cross bikes with discs this year, though only front, not rear.
For road use, I dont think there will be much benefit to be had, discs
excel in wet and muddy conditions, but for their benefits, you have the
penalty of the extra weight to carry, of which roadies tend to not want -
if something is 10g lighter than a competitior, then people buy the 10g
lighter product.
I could see a benefit in touring bikes, but if you are going on a
tour, having to carry spares would be a pain, as although easily got
mail-order, many local bike shops will not keep the disc spares in stock,
whereas they will almost certainly have spares for caliper brakes.
Alan.

--
To reply by e-mail, change the ' + ' to 'plus'.
http://www.dvatc.co.uk - Off-road cycling in the North Midlands.

[email hidden] (Stefan) wrote in news:ac070dd8.0405171024.c6723b1
@posting.google.com:

Quoted message said:

I was chatting with my riding buddies this last weekend and we started
a discussion on why road bike companies have not adopted disc brakes
for road bikes? It seems to me that the greater stopping power would
be a good idea, especially for hilly riding.

Some tandems have disc brakes. Most roadies probably don't want to pay the
weight penalty. Mountain bikers like disc brakes because the work in muddy
conditions, but road bikers don't often have that problem.

"Stefan" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Hi all,

I was chatting with my riding buddies this last weekend and we started
a discussion on why road bike companies have not adopted disc brakes
for road bikes? It seems to me that the greater stopping power would
be a good idea, especially for hilly riding.

I'm curious as to what you all think? Should road bike disc brakes be
created and how come they don't exist today?

Cheers,
Stefan

They do exist:
http://www.avidbike.com/2_cpsdiskbrakes/cps2_2_road.html

They're not hugely popular because the value, if not necessity, of disc
brakes has been largely overstated. Unless you're doing very aggressive
mountain bike riding caliper brakes work fine (and, I'm a pretty aggressive
mountain bike rider). Also, high-performance roadies, the sort who would
benefit most from discs, are notorious gram-counters and discs are much
heavier than caliper brakes.

Now that that is out in the open, I imagine all sorts of arguments will
appear for and against discs. That's not my intention, so don't bother.

Chris

Stefan Bolka said:

I was chatting with my riding buddies this last weekend and we
started a discussion on why road bike companies have not adopted
disc brakes for road bikes? It seems to me that the greater
stopping power would be a good idea, especially for hilly riding.

Quoted message said:

I'm curious as to what you all think? Should road bike disc brakes
be created and how come they don't exist today?

You assume there is a lack of stopping power in your opening
statement. I think you need to substantiate that first. Secondly,
road racing bicycles are the way they are mainly because changing to
discs adds complexity, weight and is not easily integrated with the
controls currently in use. People have been working on that and have
not made any good progress.

If they were actually better, you can bet they wouldn't be on the
sidelines. If they do come into play some day, it will probably be
mainly through people like yourself who favor them unquestionably.
That's how we got higher mechanical dual pivot brakes. There were
enough avocational bicyclists, who make up the bulk of the retail
market, who did not have enough strength to use the previous brakes
with a 4:1 ratio. The same goes for frame fit Silca tire pumps with
which people regularly broke off valve stems and failed to achieve
ridable pressure. Brake lever shifting was introduced in response to
people who could not pedal wile riding one handed... which made
shifting awkwardly difficult.

Jobst Brandt
[email hidden]

Stefan said:

Hi all,
I was chatting with my riding buddies this last weekend and we started a
discussion on why road bike companies have not adopted disc brakes for
road bikes? It seems to me that the greater stopping power would be a
good idea, especially for hilly riding.
I'm curious as to what you all think? Should road bike disc brakes be
created and how come they don't exist today?
Cheers, Stefan

Current big detractions:
1. Weight.
2. Fork and frame attachements and appropriate structural and safety
considerations.
3. Weaker wheels due to decreased spoke support angles.
4. Many different configurations of discs, calipers, mechanical and
hydraulics, etc. (Most don't work well with Brifters)
5. Interference with rack and fender mounting also seem to make them
tough to use for touring.

Superior stopping power and no rim brake track wear are some of the good
things. Rim heating goes too.

There is a future for them. Sheldon Brown wrote an article for Adventure
Cycling magazine that covers many of the issues. I was planning to
provide a link to the article, but it isn't on the site yet.

--

In article <[email hidden]>,

Stefan said:

Hi all,

I was chatting with my riding buddies this last weekend and we started
a discussion on why road bike companies have not adopted disc brakes
for road bikes? It seems to me that the greater stopping power would
be a good idea, especially for hilly riding.

With a decent braking surface (naked aluminum without anodizing), road
brakes have enough power to lift the rear wheel off the ground. More
braking force isn't necessary. The mechanical advantage provided by dual
pivot brakes makes this easy to do from on top of the brake hoods - more
isn't necessarry. That leaves contamination - except in heavy slush/sleet,
you don't get enough gunk on the brakes, and few roadies ride in that
situation.

Quoted message said:

I'm curious as to what you all think? Should road bike disc brakes be
created and how come they don't exist today?

A dual pivot front caliper and single pivot rear are ideal from a
performance/weight standpoint.
--
<a href="http://www.poohsticks.org/drew/">Home Page</a>
Life is a terminal sexually transmitted disease.

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

Hi all,
I was chatting with my riding buddies this last weekend and we started
a discussion on why road bike companies have not adopted disc brakes
for road bikes? It seems to me that the greater stopping power would
be a good idea, especially for hilly riding.
I'm curious as to what you all think? Should road bike disc brakes be
created and how come they don't exist today?

Do you find your current brakes lacking in stopping power? I sure don't.
There is also the extra weight of the disk and caliper as compared to
the current brake standards. Having to build your front wheel
offset to accomodate the brake rotor is going to weaken the wheel. You
should also see the other discussion on wheel ejectiions caused by disc
brakes.
-----------------
Alex

Stefan said:

Hi all,

I was chatting with my riding buddies this last weekend and we started
a discussion on why road bike companies have not adopted disc brakes
for road bikes? It seems to me that the greater stopping power would
be a good idea, especially for hilly riding.

I'm curious as to what you all think? Should road bike disc brakes be
created and how come they don't exist today?

There isn't really anything wrong with the current method; it's light,
fairly cheap and uses a huge disc - the wheel rim. Road forks are also
quite slender and would need to be beefed up considerably for a hub
brake of any kind. Some touring bikes - which are increasingly
MTB-derived - have discs, but they're quite heavily built.

MTBs suffer more from bent wheels and sticky mud, and even there the
case for discs is far from clear.

(Stefan) said:

I was chatting with my riding buddies this last weekend and we
started a discussion on why road bike companies have not adopted
disc brakes for road bikes? It seems to me that the greater
stopping power would be a good idea, especially for hilly riding.

I'm curious as to what you all think? Should road bike disc brakes
be created and how come they don't exist today?

Well, to be pedantic about it caliper brakes are already disk brakes.
;-) Disk brakes are being offered on some road bikes, at least on some
tandems. At this point they weigh more and there are other concerns
about the current design. There's a whole 'nother thread going on
about this right now in rec.bikes.tech and there have been several
threads about some of the other concerns- such as front wheel ejection
from braking forces- if you care to check the archives at Google.

I've never had a problem with standard rim brakes and I see no
advantage to disk brakes for me. Some have pointed out the issue with
rim heating when braking is prolonged, such as when riding in
mountains. I live in flat-to-rolling terrain and have never
encountered this issue. I rode in the Alps for 10 days in 2002 and
while my rims got warm they never overheated. Other people with more
experience than I in the mountains have reported significant issues.
If I was tandeming in the mountains, I could see some value to disk
brakes regarding the heating issue. The odds of this happening for me
are pretty slim, my wife hates climbing with a bike even though she
loves to backpack. There may be some concerns about the disks'
ability to tolerate heating without distorting (see the other thread).

Some report that disk brakes offer a smoother and more easily
modulated feel to the brake lever. I found the opposite, that the
brakes were grabby, but that was a couple of years ago and perhaps
those brakes weren't set up right or the technology has improved.

Tim McNamara said:

I've never had a problem with standard rim brakes and I see no
advantage to disk brakes for me.

my cyclocross/touring bike has a front disc brake & that was primarily to
fix a fork shudder problem (it did that quite nicely) which is another way
of saying i probably wouldn't have done it otherwise.

that said ..

Quoted message said:

Some have pointed out the issue with
rim heating when braking is prolonged, such as when riding in
mountains. I live in flat-to-rolling terrain and have never
encountered this issue. I rode in the Alps for 10 days in 2002 and
while my rims got warm they never overheated. Other people with more
experience than I in the mountains have reported significant issues.

they are definitely better w/r/t heating. but a rim brake can take a fair
bit of heating .. it takes a lot of steep, very technical descents to make
it happen. i'm in the mountains and it's pretty rare for me that it gets
that bad. but it is nice not to have to worry (except of course that now
you all have me watching my q/r ;-) ..

Quoted message said:

If I was tandeming in the mountains, I could see some value to disk
brakes regarding the heating issue.

[snip]

Quoted message said:

There may be some concerns about the disks'
ability to tolerate heating without distorting (see the other thread).

well, that'd probably be well after a similiar rim brake setup was out of
commission, anyway.

Quoted message said:

Some report that disk brakes offer a smoother and more easily
modulated feel to the brake lever. I found the opposite, that the
brakes were grabby, but that was a couple of years ago and perhaps
those brakes weren't set up right or the technology has improved.

mine modulate just fine and they are certainly not grabby. they "feel"
different (and i believe me i know, my rear is still a canti) but there's
nothing in the least objectionable about them (avid mech).

& tim, they kick ass in the snow ;-)
--
david reuteler
[email hidden]

Quoted message said:

why road bike companies have not adopted disc brakes for road bikes?

They have no motive to do so.

Quoted message said:

It seems to me that the greater stopping power would
be a good idea, especially for hilly riding.

Disks have stopping power greater than good rim brakes only in some
circumstances: rain, mist, mud, hot-braking mountain descent, and
similar conditions to which most roadies do not intentionally subject
themselves. They wouldn't put up with the additional weight, anyway.

(Stefan) said:

I was chatting with my riding buddies this last weekend and we started
a discussion on why road bike companies have not adopted disc brakes
for road bikes? It seems to me that the greater stopping power would
be a good idea, especially for hilly riding.

I'm curious as to what you all think? Should road bike disc brakes be
created and how come they don't exist today?

You assume that disc brakes are more powerful than rim brakes. They
are not. That is immaterial for most riders anyway, who have more
potential braking torque than they are able to use regardless which
type of brakes they employ.

The chief advantage of disc brakes is that they separate the rims's
structural duties from its braking duties. This allows good braking
to be maintained even if the rim is contaminated or bent, which are
not everyday concerns for road cyclists.

The "feel" improvements attributed to disc brakes are actually due to
the hydraulics or fully-housed cables that control them, and not to
the discs themselves. There are hydraulic rim brakes available, which
offer similar improvements in "feel" along with more maximum braking
power than discs can offer.

I use discs on a couple of my bikes, for the primary purpose of
allowing fatter tires than would otherwise be convenient to install,
and for the secondary purpose of eliminating rim wear and its
attendant filth resulting from wet riding. I do not use them to get
more or better braking than is available from rim brakes, because they
don't offer that.

Chalo Colina

"Chalo" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

[email hidden] (Stefan) wrote:
I do not use them to get
more or better braking than is available from rim brakes, because they
don't offer that.

Really? I find a DISTINCT difference between Avid V-brakes (SD 7) and
Avid's cable-actuated disc brakes. I weigh 200lbs, so maybe it can be
attributed to larger weights, but overall the disc brakes are substantially
more powerful than rim brakes.

Jan

RE/

Quoted message said:

I'm curious as to what you all think? Should road bike disc brakes be
created and how come they don't exist today?

One recollection I have of my road bike was that it was kind of scarey to ride
in the rain.... So maybe I would have gone for a front disc....
--
PeteCresswell

(Pete Cresswell) said:

RE/

Quoted message said:

I'm curious as to what you all think? Should road bike disc brakes be
created and how come they don't exist today?

One recollection I have of my road bike was that it was kind of scarey to ride
in the rain.... So maybe I would have gone for a front disc....

I've heard a lot of people complain that they feel their brakes are
useless in the rain. I have no problems at all myself. I'm more
concerned about reduced traction on the road surface, because I can more
easily lock my rim brakes when they're wet!

Given that, how about another alternative for heavy weather - roller
brakes? They seem to be the ticket not for road riding, but rather for
all-weather commuting.

-Collin

Stefan Bolka said:

Quoted message said:

I was chatting with my riding buddies this last weekend and we
started a discussion on why road bike companies have not adopted
disc brakes for road bikes? It seems to me that the greater
stopping power would be a good idea, especially for hilly riding.

Quoted message said:

I'm curious as to what you all think? Should road bike disc brakes
be created and how come they don't exist today?

You assume there is a lack of stopping power in your opening
statement.

After riding a rainy half-century yesterday, I would have to agree.
It's been a long time since I rode a freewheeling bike in wet
conditions, and it was sometimes scary. Not scary enough to keep me
from hitting 42 mph on one of the descents though! (A new record for my
Thorn Raven http://sheldonbrown.org/throrn.)

Quoted message said:

I think you need to substantiate that first. Secondly,
road racing bicycles are the way they are mainly because changing to
discs adds complexity, weight and is not easily integrated with the
controls currently in use. People have been working on that and have
not made any good progress.

Not clear if Bolka is referring to _racing_ equipment when he says
"road" though that is often used as a synonym.

Quoted message said:

If they were actually better, you can bet they wouldn't be on the
sidelines. If they do come into play some day, it will probably be
mainly through people like yourself who favor them unquestionably.
That's how we got higher mechanical dual pivot brakes. There were
enough avocational bicyclists, who make up the bulk of the retail
market, who did not have enough strength to use the previous brakes
with a 4:1 ratio. The same goes for frame fit Silca tire pumps with
which people regularly broke off valve stems and failed to achieve
ridable pressure. Brake lever shifting was introduced in response to
people who could not pedal wile riding one handed... which made
shifting awkwardly difficult.

Yes, and in the automotive world, electric starters came along 'cause
effete drivers were too wussy to turn the crank like a Real Man.

Then the synchromesh transmission was introduced for the benefit of
klutzes who couldn't manage to learn the simple technique of
double-clutching...and don't get me started about safety glass,
seatbelts and power steering!...

Sheldon "Those Were The Days...?" Brown
+----------------------------------------------------------+
| The people who live in a Golden Age usually go around |
| complaining how yellow everything looks. |
| -- Randall Jarrell |
+----------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

In article <[email hidden]>, Sheldon Brown

Quoted message said:

After riding a rainy half-century yesterday, I would have to agree.
It's been a long time since I rode a freewheeling bike in wet
conditions, and it was sometimes scary. Not scary enough to keep me
from hitting 42 mph on one of the descents though! (A new record for my
Thorn Raven http://sheldonbrown.org/throrn.)

This is better:

http://www.sheldonbrown.org/thorn/

luke

Quoted message said:

Then the synchromesh transmission was introduced for the benefit of
klutzes who couldn't manage to learn the simple technique of
double-clutching...and don't get me started about safety glass,
seatbelts and power steering!...

Sheldon "Those Were The Days...?" Brown

Ever been to the workshop area of an old farm? All those belts going every
which-way with no protective covers... yikes, I never looked hard enough,
but I'm sure they must have had an emergency saw stashed in a safe place
just for quick amputations...

--Mike--
(Who spent a fair amount of time on the Grandparent's farm as a kid, and
thought the workshop area was really cool)
Chain Reaction Bicycles
http://www.ChainReactionBicycles.com

Mike Jacoubowsky said:

Quoted message said:

Then the synchromesh transmission was introduced for the benefit of
klutzes who couldn't manage to learn the simple technique of
double-clutching...and don't get me started about safety glass,
seatbelts and power steering!...

Sheldon "Those Were The Days...?" Brown

Ever been to the workshop area of an old farm? All those belts going every
which-way with no protective covers... yikes, I never looked hard enough,
but I'm sure they must have had an emergency saw stashed in a safe place
just for quick amputations...

--Mike--
(Who spent a fair amount of time on the Grandparent's farm as a kid, and
thought the workshop area was really cool)
Chain Reaction Bicycles
http://www.ChainReactionBicycles.com

Dear Mike,

Little need for emergency saws. The powered belts usually pull the
fingers and limbs into the pulleys at a brisk enough pace to separate
things just as effectively as gears, chains, and other mechanical
hazards.

You can confirm this by spending half an hour counting fingers at a
hardware or auto parts counter patronized by farmers and ranchers.
You'll meet a surprising number of nine-fingered ladies, too.

Of course, they might all be penitent Yakuza members, but the John
Deere caps suggest otherwise.

Carl Fogel