Do I want disc brakes?

I am used to rim brakes.

But I am in the market for a new bike, and the ones that interest me
come with disc brakes.

Do I want disc brakes?

Or should I limit my choice of bikes to those with rim brakes?

Most of my riding is on streets and urban dirt paths. I want the
ability to go off-road occassionally; but by off-road, I mean
relatively tame mountain trails, not downhill racing and jumps. In
any case, I do not anticipate biking in sloppy (wet) conditions.

WhatsUp wrote:

I am used to rim brakes.

But I am in the market for a new bike, and the ones that interest me
come with disc brakes.

Do I want disc brakes?

Or should I limit my choice of bikes to those with rim brakes?

Most of my riding is on streets and urban dirt paths. *I want the
ability to go off-road occassionally; but by off-road, I mean
relatively tame mountain trails, not downhill racing and jumps. *In
any case, I do not anticipate biking in sloppy (wet) conditions.

I think discs will more than likely be a letdown for you. They have
more points of failure and not surprisingly, more frequent failures
(as defined by problems requiring some mechanical attention rather
than those that leave you walking). Compared to rim brakes, they are
more likely to drag, make noise, or get bungled in the course of
routine bike parking and storage. Hydraulics are a nuisance to
maintain and generally not field-serviceable. Mechanical discs are
just as demanding to set up as rim brakes.

Discs are a compromise with some of the advantages of rim brakes
(strong momentary braking power, responsive lever feel) and some of
the advantages of drum brakes (all-weather reliability, relative
cleanliness, no rim wear). But they require more maintenance and
intervention than rim brakes and a whole lot more than drums. Though
discs are plenty strong for general use, they can't dissipate as much
continuous braking energy as good rim brakes. And while they are much
cleaner than rim brakes, they are not nearly as clean as drum or
coaster brakes.

Disc brakes offer no power advantage, no weight advantage, and no
reliability advantage. All you get for your trouble and expense is
improved tolerance of filth and rim damage and maybe nicer lever feel
(if you're lucky).

Chalo

On 2009-07-15, Chalo wrote:
[...]
Though discs are plenty strong for general use, they can't dissipate
as much continuous braking energy as good rim brakes.

Are you sure about that? Although a disk is smaller, it can run hotter.
So I don't know whether it's a better dissipator overall or not.

How much hotter though is the problem-- you don't get tyre blowoff but
you do get fluid boiling and probably pad fade. Someone posted a link to
a test once that found that disk brakes actually did not work any better
on long descents.

They should be better, but it doesn't mean they are.

Ben C wrote:
Are you sure about that? Although a disk is smaller, it can run
hotter.

In the only test I've seen the larger disks ran at sustained 700W
dissipation, which is in the range of rims.


How much hotter though is the problem-- you don't get tyre blowoff
but you do get fluid boiling and probably pad fade.

Some vendors have started to offer heat sinks at the caliper and
recommend metal brake tubing for heavy duty...


They should be better, but it doesn't mean they are.

Adding size and weight they can be, as any motor vehicle disk brake
demonstrates. Cyclist tend to be shy on the weight side 8)

--
MfG/Best regards
helmut springer panta rhei

On Jul 15, 2:28*am, WhatsUp wrote:
I am used to rim brakes.

But I am in the market for a new bike, and the ones that interest me
come with disc brakes.

Do I want disc brakes?

Or should I limit my choice of bikes to those with rim brakes?

Most of my riding is on streets and urban dirt paths. *I want the
ability to go off-road occassionally; but by off-road, I mean
relatively tame mountain trails, not downhill racing and jumps. *In
any case, I do not anticipate biking in sloppy (wet) conditions.

Remember the 'reasons' for discs on a bicycle(not the market speak).
Great for wet, muddy, sloppy and great when you have a high
possibility of wacking the rim, but still need to 'get out' of the
area you are in. More expensive, more complicated(particularly
hydraulics). For your 'needs', I think v brakes would be fine and
dandy.

Look around. Bicycles with rim brakes at the same price point as those
with discs often have better 'stuff' them, like suspension.

On Jul 15, 3:28*am, WhatsUp wrote:
I am used to rim brakes.

But I am in the market for a new bike, and the ones that interest me
come with disc brakes.

Do I want disc brakes?

Or should I limit my choice of bikes to those with rim brakes?

Most of my riding is on streets and urban dirt paths. *I want the
ability to go off-road occassionally; but by off-road, I mean
relatively tame mountain trails, not downhill racing and jumps. *In
any case, I do not anticipate biking in sloppy (wet) conditions.

What kinda bike is it? If it's a mtb, you're pretty much stuck with
discs. Not the worst thing in the world as the cheaper cable operated
models by Hayes and Tektro have evolved beyond 100% suck (first
generation Deore anyone? Ugh)

I pretty much agree with Chalo, especially considering that you don't
ride in wet conditions.

On Jul 15, 1:28*am, WhatsUp wrote:
I am used to rim brakes.
[....]
Do I want disc brakes?

Thanks for all the constructive comments so far. Pretty much
confirmed what I thought I had heard about disc brakes in the past.

On Jul 15, 8:23*am, landotter wrote:
On Jul 15, 3:28*am, WhatsUp wrote:

I am used to rim brakes.

But I am in the market for a new bike, and the ones that interest me
come with disc brakes.

Do I want disc brakes?

Or should I limit my choice of bikes to those with rim brakes?

Most of my riding is on streets and urban dirt paths. *I want the
ability to go off-road occassionally; but by off-road, I mean
relatively tame mountain trails, not downhill racing and jumps. *In
any case, I do not anticipate biking in sloppy (wet) conditions.

What kinda bike is it? If it's a mtb, you're pretty much stuck with
discs. Not the worst thing in the world as the cheaper cable operated
models by Hayes and Tektro have evolved beyond 100% suck (first
generation Deore anyone? Ugh)

I pretty much agree with Chalo, especially considering that you don't
ride in wet conditions.

Nothing feels as positive and modulates as well as a dual pivot, but I
am perfectly happy with the discs on my commuter. The only problem I
have had (after learning how to properly adjust them) was pad wear,
and the fact that I can dial them down and wear them out until the
return springs hit the rotors. In other words, if I am not paying
attention to wear, I can get myself in to trouble.

If I lived in Arizona or some other dry climate, I wouldn't bother
with them -- except on a tandem, where rim heat build up with two
large riders would be a problem, and unlike Chalo, I do not find drum
brakes that effective as a primary brake, but then maybe I have not
used a good drum brake in the past. -- Jay Beattie.

"WhatsUp" wrote in message
...
On Jul 15, 1:28 am, WhatsUp wrote:
I am used to rim brakes.
[....]
Do I want disc brakes?

Thanks for all the constructive comments so far. Pretty much
confirmed what I thought I had heard about disc brakes in the past.

I can only speak from my experience, I've got hydraulic discs on
my mtn bike and cantilever rim on my road bike.

I've never had any problem with the discs. There's been no maintainance.
They are very responsive. I've had occassional squeaks that disappeared.

I've never had any problem with rims. I have to adjust them occasionally.
They do slip a bit when wet whereas the discs are always solid.
Crap has gotten between the pad and the rim and there are scratches/gouges
but I haven't noticed any effect on the braking.

When I remove a wheel I have to deflate the tire to get it past the rim
brakes.
No problem pulling a wheel with a disc brake................
BUT_____if the lever gets squeezed and the pads press together without
a disc in between you may be f***ed, they can stick together and I've heard
it can be impossible to separate them again. Not wanting that outcome I
have
always stuck a piece of cardboard between them when the wheel is out.

I'd prefer disc's on a mtn bike especially on a sloppy trail or steep
downhills..
I've never felt that the lesser "performance" of rims was any
problem on any ride on my road bike, even in the wet.
I'd never knock discs for reliability or performance and in my opinion
it's a "better" brake but in my experience it's a lot more than I need
for braking on the road.

JP

On Jul 15, 9:28*am, WhatsUp wrote:
I am used to rim brakes.

But I am in the market for a new bike, and the ones that interest me
come with disc brakes.

Do I want disc brakes?

Or should I limit my choice of bikes to those with rim brakes?

Most of my riding is on streets and urban dirt paths. *I want the
ability to go off-road occassionally; but by off-road, I mean
relatively tame mountain trails, not downhill racing and jumps. *In
any case, I do not anticipate biking in sloppy (wet) conditions.

I've had all the brake types you'll find mentioned here, and on my
current bikes have discs, modern drum brakes, hydraulic rim brakes.

Discs are tiresome and expensive, high maintenance items, and fragile
too in stupid ways. They're not necessarily all that nice to ride with
for relaxation because they have modulation problems. They need to be
set up just so to stop better than other kinds of brakes; that defeats
their theoretical advantages except in competition.

Shimano's roller brokes in their latest -70/75 incarnation have the
same stopping power as discs and very low maintenance (once a year or
not until they start complaining, if you wish). The only downside is
that the best roller brakes need attention to how you apply them, just
like disc brakes; they are more easily modulated than discs but
nowhere near perfect in that respect.

It is a pity that roller brakes aren't more common in the States
because they would be your ideal solution. I use rollerbraked bikes in
the same sort of environment that you envisage.

I also have hydraulic rim brakes by Magura, and these are the best
compromise between the stopping power of roller brakes and discs on
the one hand, and on the other hand the ultra-low maintenance of
roller brakes and the tractability and stopping power of rim brakes.
They cost no more than really good mechanical rim brakes and are
totally maintenance free. Check that again: zero maintenance (huge
numbers are thrown about by RBT Magura rim brake owners for pad
mileages).

So, an order of (personal) preference in cases where racing or extreme
competition or very hard usage do not dictate high-maintenance discs:

1. Roller brakes of the latest Shimano type.

2. Hydraulic rim brakes.

3. Good mechanical rim brakes.

4. Disc brakes. (Cheap hydraulics are not worth having, the good
mechanicals require frequent adjustment but work reliably if regularly
checked and maintained, the expensive hydraulics can be messy to
service. Swings and roundabouts.)

Less maintenance means more riding time. Brakes should be fit-and-
forget parts: those are numbers 1 and 2 above. Note that Shimano's
roller brakes are the cheapest option of all.

Butbutbut... If the only bike that will make you happy comes only with
disc brakes, *learn to ride with them, learn to maintain them*: it
will be the price of the pleasure the rest of the bike provides. The
truth is, almost any brakes will do for most riding; that every
component should be the extreme best is a pose of the RBT macho men,
who like to pretend they ride on the limit all the time, whereas the
truth is that most of us never even reach halfway to the limit.

I have an example: I had no experience with the Magura hydraulic rim
brakes, indeed considered them a gimmick for cafe wannabes. But my
Utopia Kranich, which I really, really wanted for the frame and tyre
formats (my entire shortlist was only two bikes in all the world),
came only with a choice of hydraulic brakes, either disc or rim. For a
while i toyed with the idea of taking the discs, at least the known
evil, then I opted for the new experience, took the Magura hydraulics,
and have been very happy with them, especially their main feature
which is that of all the brake types I know they are the most docile,
requiring no thought, so that I have more attention for everything
else, even when speeding downhill; they also stop more than well
enough and even in the wet are not noticeably inferior to disc
brakes.

But the point isn't that the brakes have worked out better than I
expected; even if they were only as good as cheap mechanical rim
brakes, I would have been over the moon because the rest of the bike
is so pleasing in fit and operation, so good to look at and touch,
that I'm always keen to ride. I shudder when I think I could have
chosen a less well-fitting bike because it had roller brakes, and not
had the superb fit...

Sun's shining. Off to ride!

Andre Jute
Visit Jute on Bicycles at
http://www.audio-talk.co.uk/fiultra/...20CYCLING.html