Rim vs. disc brakes

Leo Lichtman said:

I don't understand why disc brakes exist on bicycles. Are they better? It
looks like the rim has better leverage, and no added weight.

They exist because people will buy them, and in most cases pay a
premium to get them.

Whether thay are needed or valuable is a matter of opinion in some
cases, and a matter of specific circumstances in others.

In long descents at speed, a disc brake will not cause rim
overheating; for those who use tubulars, this could be a crucial
advantage.

In very wet and muddy conditions, a disc brake's performance can be
better or more predictable than a rim brake's, though this is almost
entirely dependent upon the specific systems being compared; I
personally have a front disc that's not as effective as the rim brake
on two of my other bikes, either wet or dry.

Many disc brake users find that the discs' stopping power is easier to
modulate; others find that to achieve the same level of braking, the
disc must be applied with much greater force. These varying (but not
necessarily conflicting) observations may be due in part to the fact
that there is no standard for comparison; there's quite a bit of
variation in rim brake performance, and in disc brake performance.

Only the individual rider can determine if discs provide any advantage
*for them*, and it should be noted that in some cases, the advantage
(in either direction) may be definable only as "they're better because
I like them more than the other ones."

--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Surrealism is a pectinated ranzel.

Leo Lichtman said:

I don't understand why disc brakes exist on bicycles. Are they better?
It looks like the rim has better leverage, and no added weight.
--
Leo Lichtman
[email hidden]

Tandems have so much weight and go so fast downhill with all that weight
and only slightly higher aero resistance over single rider bikes that if
rim brakes were relied upon soley one could overheat and blow the tube.

Rim brakes are substantially affected by mud, dirt, and water, so
mountain bikes in environs likely to recieve this exposure need a
braking system that won't fail due the environs.

Commuting bikes need reliable rain brakes, so a drum or disc can satisfy
that requirement.

Road bikes and recumbents generally riding on dry pavement usually rely
on the lighter and less expensive rim brakes.

--

Leo-<< I don't understand why disc brakes exist on bicycles. Are they better?
It
looks like the rim has better leverage, and no added weight. >><BR><BR>

Great for muddy, really wet conditions, huge downhills, rides where wacking a
rim is a large proibability. NO use on a standard road bike. Unique forks,
hubs, levers(Hydraulic) framesets, higher weight, cost, complexity. Answer to a
not asked question, like tubeless on a road bike.

Mavic sure is behind this 'craze' 100%. A way to sell more of their goofy
wheel.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

Leo Lichtman said:

I don't understand why disc brakes exist on bicycles. Are they
better? It looks like the rim has better leverage, and no added
weight.

I can save you some time and the rest of us some bandwidth. Go to
www.google.com and click on 'Groups.' Then navigate your way to
rec.bicycles.tech and search for 'disk brakes' and read the thousands
of posts already written about this.

The short answer is that disk brakes are good for muddy conditions.
Disk or drum brakes are good for tandems being ridden in mountainous
terrain where lots of braking can cause problems with rims
overheating. Other than that, they are an answer to a problem that
didn't exist.

The cons for disk brakes are weight, incompatibility with road levers
(IIUC), and the risk of your front wheel coming out of the dropouts.

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

Quoted message said:

I don't understand why disc brakes exist on bicycles. Are they better? It
looks like the rim has better leverage, and no added weight.

I find a rear disc on my tourer is less easily fouled by luggage than
conventional brakes, where stuff on the rack or the tops of paniers
did get in the way of the brakes.

Also more consistent in the wet than rim brakes, easier to adjust for
optimal performance.

Still works without rubbing when I buckle the wheel.

But performance gains in good conditions, no.

Andrew Webster

Like usual -- in this group you get "experts" chiming in with their half
baked knowledge.

I have built up a Kona Major Jake with disc brakes, I use this both as a CX
bike and my city bike. Its wonderful to fly through the city, and know that
you can easily stop from any speed with two finger pressure. On big decents,
you can control your speed without worrying about fade, as these puppies
work better once their hot.

I have Avid Ball Bearing mechanical brakes, which are specifically for road
levers, and are 100% compatible with them (I guess the experts don't know
everything).

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

Quoted message said:

Leo Lichtman said:

I don't understand why disc brakes exist on bicycles. Are they
better? It looks like the rim has better leverage, and no added
weight.

I can save you some time and the rest of us some bandwidth. Go to
www.google.com and click on 'Groups.' Then navigate your way to
rec.bicycles.tech and search for 'disk brakes' and read the thousands
of posts already written about this.

The short answer is that disk brakes are good for muddy conditions.
Disk or drum brakes are good for tandems being ridden in mountainous
terrain where lots of braking can cause problems with rims
overheating. Other than that, they are an answer to a problem that
didn't exist.

The cons for disk brakes are weight, incompatibility with road levers
(IIUC), and the risk of your front wheel coming out of the dropouts.

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.711 / Virus Database: 467 - Release Date: 6/28/2004

"Qui si parla Campagnolo " <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Leo-<< I don't understand why disc brakes exist on bicycles. Are they

better?

Quoted message said:

It
looks like the rim has better leverage, and no added weight. >><BR><BR>

Great for muddy, really wet conditions, huge downhills, rides where

wacking a

Quoted message said:

rim is a large proibability. NO use on a standard road bike. Unique forks,
hubs, levers(Hydraulic) framesets, higher weight, cost, complexity. Answer

to a

Quoted message said:

not asked question, like tubeless on a road bike.

Mavic sure is behind this 'craze' 100%. A way to sell more of their goofy
wheel.

Heh heh, yeah Mavic goofy wheels. I couldn't agree more on that one. I'll
never buy another Mavic.

BTW, I remember mountain biker Roland Green held out on disc upgrades for
his trusty XTR v-brakes for about 2 years before the powers that be forced
his hand. He's now riding a dual suspension disc beast (not sure if it's
helping him).

JayofMontreal said:

Like usual -- in this group you get "experts" chiming in with their
half baked knowledge.

Whereas you know better, eh?

Quoted message said:

I have built up a Kona Major Jake with disc brakes, I use this both
as a CX bike and my city bike. Its wonderful to fly through the
city, and know that you can easily stop from any speed with two
finger pressure. On big decents, you can control your speed without
worrying about fade, as these puppies work better once their hot.

Huh. I can stop my road bike with one or two finger pressure with my
rim brakes (Campy 9 sp Ergo levers and Sun Tour Superbe Pro calipers).
Not a problem. I've never experienced brake fade in the 35 years I've
been riding bikes. Oh well. Perhaps I'm just not an extreme rad cool
biker dude like you, eh? Or perhaps I just know how to descend.

At least I know enough not to top post, however.

Quoted message said:

I have Avid Ball Bearing mechanical brakes, which are specifically
for road levers, and are 100% compatible with them (I guess the
experts don't know everything).

*I'm* not an expert, didn't know that and thank you for the data
point.

jack-<< BTW, I remember mountain biker Roland Green held out on disc upgrades
for
his trusty XTR v-brakes for about 2 years before the powers that be forced
his hand. He's now riding a dual suspension disc beast (not sure if it's
helping him).

Quoted message said:

Quoted message said:

<BR><BR>

Helped his wallet no doubt.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

In article <[email hidden]>, JayofMontreal

Quoted message said:

Like usual -- in this group you get "experts" chiming in with their half
baked knowledge.

I have built up a Kona Major Jake with disc brakes, I use this both as a CX
bike and my city bike. Its wonderful to fly through the city, and know that
you can easily stop from any speed with two finger pressure. On big decents,
you can control your speed without worrying about fade, as these puppies
work better once their hot.

I have Avid Ball Bearing mechanical brakes, which are specifically for road
levers, and are 100% compatible with them (I guess the experts don't know
everything).

Regular brakes, be it caliper or V-brakes, will stop easily with 1 or 2
finger pressure on big descents. In fact, I do it all the time on my
full suspension and my folding Bike Friday.. What most people don't
realise is that, what make the brakes stop well are good brake pads.

Sadly, stock pads or cheap replacement pads are just plain useless.
They do not stop very well and require too much pressure to achieve any
decent braking.
For example, the lousy pads that came with my Bike Friday were the no
names POS. I can't even stop properly on a 4% grade downhill -- I have
to put my foot down. It's that bad. Guess what.. Once I have
upgraded the pads to Koolstop Salmon pads on the front and rear, they
stop my bike even on a long Mt Seymour downhill ride (10% grade) with
little to no effort at all. That's how much an improvement good pads
can stop a bike.

In article <[email hidden]>, Andrew

Webster said:

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

Quoted message said:

I don't understand why disc brakes exist on bicycles. Are they better? It
looks like the rim has better leverage, and no added weight.

I find a rear disc on my tourer is less easily fouled by luggage than
conventional brakes, where stuff on the rack or the tops of paniers
did get in the way of the brakes.

Good racks like those made by Old Man Mountain do not have these
issues. In fact, cheapo racks do not hold up to the abuse of long
distance touring anyhow.

Quoted message said:

Also more consistent in the wet than rim brakes, easier to adjust for
optimal performance.

If you use good pads -- Koolstop Salmon or another one a friend is
using which is a triple compound, stopping in the wet is no problem. I
know this well because I live in the wet coast of Vancouver.

Quoted message said:

Still works without rubbing when I buckle the wheel.

Except that it doesn't work when the rotor gets warped. Prolong
heating of the rotor or even during transport can warp it. It's harder
to true a warped rotor than a wheel. I know.. A friend of mine had 2
rotors damaged during his flight to Moab. SOL I guess.

Quoted message said:

But performance gains in good conditions, no.

Cable disc brakes can suffer the same performance degradation as rim
brakes -- cable friction caused by water accumulation and muck. When
the cables get muck and corrosion due to you not cleaning them, their
performance will degrade overtime. That's why hydraulic is a bit more
superior in this department. By hydro brakes can be messy to set up
and touring with hydros mean you need to carry a bleed kit and oil.

Disc brakes are good for what they are and if you get them free already
with the new bike, I see no reason to do anything but ride the bike.
But if the original poster is contemplating on putting disc to increase
stopping power, I would suggest the poster to replace brake cables,
housings and good pads before plunging mega bucks on a disc system.

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

Quoted message said:

I don't understand why disc brakes exist on bicycles. Are they better? It
looks like the rim has better leverage, and no added weight.

If you bend your rim, you still have brakes. Some claim more braking power,
but canti's have plenty of power for me.
-------------
Alex

Leo Lichtman said:

I don't understand why disc brakes exist on bicycles. Are they better? It
looks like the rim has better leverage, and no added weight.

Others have mentioned discs' improved stopping power over rim brakes,
but this simply isn't true. Those who say discs stop harder are
unaccustomed to how powerful rim brakes can be, and are probably in no
position to be able use that kind of braking power anyway.

Others have mentioned discs' tolerance of wet and messy weather
conditions and rim damage. These are genuine benefits They also
eliminate rim abrasive wear and a large amount of the filth that gets
splattered all over rim-braked bikes in wet weather.

However, I see the chief benefits of discs in their separation of
braking issues from other design choices related to the rims and
tires. There are many "given" design attributes of bicycles that are
not in fact preferred, but rather imposed by the design of rim brakes.

Use discs, and your bike no longer cares what wheel size you are
using. All rim brakes place _some_ constraint on tire size, for
instance. Discs do not. Rim brakes work with at most a couple of
similar rim diameters. Discs will brake whatever is laced to them.

Discs allow the use of any rim width that fits within a given frame.
Snowbikes, for instance, use extra-wide rims for flotation, and brake
stud placement was nonstandard as a result-- meaning that the only
wheels that would go in your snowbike were snowbike wheels. With
discs, you can put snowbike wheels and cross-country racing wheels and
road bike wheels all on the same frame.

Likewise, discs allow the rim to be composed of any material,
regardless of whether that material is suitable to withstand braking
friction. Carbon fiber, wood, nylon, painted metal; it doesn't
matter.

Discs allow vehicles with stub axle wheels (trikes, quads, Cannondale
Lefty etc.) to have adequate braking without gratuitous arches over
the tires. Drum brakes were formerly used for this and have many of
the benefits of discs, but strong braking is not one of them.

Disc brakes can be placed elsewhere in the drivetrain than at the
wheel (like on the axle of a trike).

These are some of the advantages and possibilities that disc brakes
make available. If no such advantages apply, then rim brakes will do
the job more cheaply, with less weight. But to say rim brakes are
better for all bikes is defining "bikes" pretty unimaginatively.

Chalo Colina

David said:

Andrew Webster said:

I find a rear disc on my tourer is less easily fouled by luggage than
conventional brakes, where stuff on the rack or the tops of paniers
did get in the way of the brakes.

Good racks like those made by Old Man Mountain do not have these
issues. In fact, cheapo racks do not hold up to the abuse of long
distance touring anyhow.

Quality racks by Tubus, Jandd, Nitto, Bruce Gordon, Sakkit, and others
do have those issues sometimes. Old Man Mountain racks are an
imaginative solution to the problem of mounting a rack on a frame
without enough braze-ons, but they are not the strongest or largest
racks out there despite being pretty heavy.

All else equal, it is a good thing that OMM racks free up space at the
seatstays, but they are not the equal of other racks in all other
respects.

Chalo Colina

I am the OP. Thank you, all. I now know a lot more than I did, about
brakes, and about bikers. It seems as though strongly held, conflicting
views can be correct, depending on your point of view and your particular
needs.

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

Quoted message said:

Leo Lichtman said:

I don't understand why disc brakes exist on bicycles. Are they better? It
looks like the rim has better leverage, and no added weight.

Others have mentioned discs' improved stopping power over rim brakes,
but this simply isn't true. Those who say discs stop harder are
unaccustomed to how powerful rim brakes can be, and are probably in no
position to be able use that kind of braking power anyway.

Others have mentioned discs' tolerance of wet and messy weather
conditions and rim damage. These are genuine benefits They also
eliminate rim abrasive wear and a large amount of the filth that gets
splattered all over rim-braked bikes in wet weather.

However, I see the chief benefits of discs in their separation of
braking issues from other design choices related to the rims and
tires. There are many "given" design attributes of bicycles that are
not in fact preferred, but rather imposed by the design of rim brakes.

Use discs, and your bike no longer cares what wheel size you are
using. All rim brakes place _some_ constraint on tire size, for
instance. Discs do not. Rim brakes work with at most a couple of
similar rim diameters. Discs will brake whatever is laced to them.

Discs allow the use of any rim width that fits within a given frame.
Snowbikes, for instance, use extra-wide rims for flotation, and brake
stud placement was nonstandard as a result-- meaning that the only
wheels that would go in your snowbike were snowbike wheels. With
discs, you can put snowbike wheels and cross-country racing wheels and
road bike wheels all on the same frame.

Likewise, discs allow the rim to be composed of any material,
regardless of whether that material is suitable to withstand braking
friction. Carbon fiber, wood, nylon, painted metal; it doesn't
matter.

Discs allow vehicles with stub axle wheels (trikes, quads, Cannondale
Lefty etc.) to have adequate braking without gratuitous arches over
the tires. Drum brakes were formerly used for this and have many of
the benefits of discs, but strong braking is not one of them.

Disc brakes can be placed elsewhere in the drivetrain than at the
wheel (like on the axle of a trike).

These are some of the advantages and possibilities that disc brakes
make available. If no such advantages apply, then rim brakes will do
the job more cheaply, with less weight. But to say rim brakes are
better for all bikes is defining "bikes" pretty unimaginatively.

Chalo Colina

If you listed all the problems with disc brakes in the same manner you
listed all the benefits ( as obscure as they may be) this post would
be about 3 times as long.

On 13 Jul 2004 09:47:12 -0700, [email hidden] (Evan

Evans) said:

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

Quoted message said:

Leo Lichtman said:

I don't understand why disc brakes exist on bicycles. Are they better? It
looks like the rim has better leverage, and no added weight.

Others have mentioned discs' improved stopping power over rim brakes,
but this simply isn't true. Those who say discs stop harder are
unaccustomed to how powerful rim brakes can be, and are probably in no
position to be able use that kind of braking power anyway.

Others have mentioned discs' tolerance of wet and messy weather
conditions and rim damage. These are genuine benefits They also
eliminate rim abrasive wear and a large amount of the filth that gets
splattered all over rim-braked bikes in wet weather.

However, I see the chief benefits of discs in their separation of
braking issues from other design choices related to the rims and
tires. There are many "given" design attributes of bicycles that are
not in fact preferred, but rather imposed by the design of rim brakes.

Use discs, and your bike no longer cares what wheel size you are
using. All rim brakes place _some_ constraint on tire size, for
instance. Discs do not. Rim brakes work with at most a couple of
similar rim diameters. Discs will brake whatever is laced to them.

Discs allow the use of any rim width that fits within a given frame.
Snowbikes, for instance, use extra-wide rims for flotation, and brake
stud placement was nonstandard as a result-- meaning that the only
wheels that would go in your snowbike were snowbike wheels. With
discs, you can put snowbike wheels and cross-country racing wheels and
road bike wheels all on the same frame.

Likewise, discs allow the rim to be composed of any material,
regardless of whether that material is suitable to withstand braking
friction. Carbon fiber, wood, nylon, painted metal; it doesn't
matter.

Discs allow vehicles with stub axle wheels (trikes, quads, Cannondale
Lefty etc.) to have adequate braking without gratuitous arches over
the tires. Drum brakes were formerly used for this and have many of
the benefits of discs, but strong braking is not one of them.

Disc brakes can be placed elsewhere in the drivetrain than at the
wheel (like on the axle of a trike).

These are some of the advantages and possibilities that disc brakes
make available. If no such advantages apply, then rim brakes will do
the job more cheaply, with less weight. But to say rim brakes are
better for all bikes is defining "bikes" pretty unimaginatively.

Chalo Colina

If you listed all the problems with disc brakes in the same manner you
listed all the benefits ( as obscure as they may be) this post would
be about 3 times as long.

Dear Evan,

What do you see as practical disadvantages to disc brakes?

Curiously,

Carl Fogel

RE/

Quoted message said:

What do you see as practical disadvantages to disc brakes?

I'm not Evan...and I use disc brakes on both my mountain bikes (v and canti on
the utility bike)... but here's a couple:

- Sensitivity To Contamination With Oil: I use Rohloff hubs and they weep oil.
Extra bumpy approach to a descent? Yikes!!!!! no rear brake.... Almost did me
in once when the descent was on loose/slippery/wet stones - the front wheel kept
locking and the rear brake was doing nothing.

- Availability Of Replacement Pads: Different disc brakes need different pads.
Not all bike shops carry even the most basic (like Avid...)...whereas I'd think
you can purchase rim pads almost anywhere.

- Reduced Repairability: I've had bikes vandalized while chained to, say, a
lightpost and one thing that was done was to cut the brake cables. Quick, easy
recovery at any bike shop...and even the possibility of a jury rig. Not so with
hydraulics.

- Steal Appeal: I'd imagine that if there were five bikes chained to a rack and
somebody only had time to steal one, they'd go for the one with disc brakes.

The last two were definately stretches, and I still like my discs...
--
PeteCresswell

In article <[email hidden]>, Chalo

Quoted message said:

David said:

Andrew Webster said:

I find a rear disc on my tourer is less easily fouled by luggage than
conventional brakes, where stuff on the rack or the tops of paniers
did get in the way of the brakes.

Good racks like those made by Old Man Mountain do not have these
issues. In fact, cheapo racks do not hold up to the abuse of long
distance touring anyhow.

Quality racks by Tubus, Jandd, Nitto, Bruce Gordon, Sakkit, and others
do have those issues sometimes. Old Man Mountain racks are an
imaginative solution to the problem of mounting a rack on a frame
without enough braze-ons, but they are not the strongest or largest
racks out there despite being pretty heavy.

All else equal, it is a good thing that OMM racks free up space at the
seatstays, but they are not the equal of other racks in all other
respects.

Chalo Colina

Actually, Bruce Gordon racks are not the strongest out there either
despite being also heavy.

How do I know this? That's because, I used to work for a company that
sponsored Pierre Bouchard and Janick Lemieux of the "Wheels On Fire" on
their first Asian trip and currently their Rings Of Fire tour and their
2 BG racks broke at the welds in 2 places!!

To be fair, I had toured extensively off and on the road with OMM racks
and had so far been satisfied with its durability and performance. If
I subject it to the same amount of stress and wear as Pierre and Janick
did to their BGs, my OMM racks will for sure break. But keep in mind
that even the best and toughest racks out there can break at the welds
under extreme stress.