MB Disc brakes

The Airman said:

I was thinking of getting a replacement mountain equipped with front and
rear disc brakes, but someone told me some time back about some safety
issue with disc brakes and front wheels falling off?

Is this correct? Is there a safety issue?

Are disc brakes that much better calipers?

Thanks

Try this:

http://groups-beta.google.com/groups?hl=en&q=disc+brakes+annan

Robin Hyooobert

The Airman said:

I was thinking of getting a replacement mountain equipped with front and
rear disc brakes, but someone told me some time back about some safety
issue with disc brakes and front wheels falling off?

Is this correct? Is there a safety issue?

Are disc brakes that much better calipers?

Thanks

if you ride in rain or mud, disk brakes are /way/ better than rim
brakes. hydraulic disk brakes in particular offer very good modulation
& ease of use, with very little, if any, fade.

regarding "the safety issue", it's been discussed at length on this
group many times. bottom line is that the "safety issue" scare is based
on a flawed assumption of the force necessary to cause slippage of an
axle in a fork as a result of disk braking forces. because that
assumption is flawed, it "appears" that forces generated by braking can
eject a front axle from a fork. reality however is that the force
necessary to cause slipage is many times that assumed in the scare,
and that's /before/ you take the fork's "lawyer lips" into account.
hence, the real math accords with what we see in practice: wheels do not
eject.

to be prudent, there is some benefit in using a front skewer that is
known to produce consistently reliable clamping such as the closed cam
shimano & campy type skewers, but the bottom line is that unless you
have outright skewer failure or don't follow manufacturer instructions
on mounting the wheel, you'll have no problems whatsoever.

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

Quoted message said:

I was thinking of getting a replacement mountain equipped with front and
rear disc brakes, but someone told me some time back about some safety
issue with disc brakes and front wheels falling off?

Is this correct? Is there a safety issue?

Are disc brakes that much better calipers?

Thanks

Been using disks for 3 years. Two different systems on three different
forks, two frames.

AFAIK, my wheels have not detached from the fork without me wanting then
too!

Ask who has returned to caliper brakes after using disks?

--
DTW .../\.../\.../\...

I've spent most of my money on mountain biking and windsurfing.
The rest, I've just wasted.

Per The Airman:

Quoted message said:

and front wheels falling off?

Is this correct? Is there a safety issue?

There have been numerous and heated threads about the wheel ejection thing.
My belief is that the lawyer lips make it moot.

One other thing, though: If you're running mechs, be sure to trim the tail of
the cable reasonably cose - like a half inch. Supposedly if the tail is long
enough, it can jam in the brake with catestrophic results if it's the front
brake.

Are they "better"?

Horses for courses. Depends on what you need are.

For the front brake, I wouldn't want anything else but my Hope C2.

For the rear brake, if my calf didn't bang on it all the time I might be using a
v-brake. As it is, I'm happy with an Avid mech.
--
PeteCresswell

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

Quoted message said:

I was thinking of getting a replacement mountain equipped with front

and

Quoted message said:

rear disc brakes, but someone told me some time back about some

safety

Quoted message said:

issue with disc brakes and front wheels falling off?

Is this correct? Is there a safety issue?

Are disc brakes that much better calipers?

Thanks

IMO:

1) Don't use any of the "mechanical" disc brakes. They are all [censored]
because they require the rotor to bend with every actuation. Thus,
with the mech disc brakes, an evenly distributed friction over the
braking surface is impossible and damage by proper use is normal.

2) If using QRs, use closed cam QR. Open-cam QR requires a grossly
inconsistent amount of actuation force to attain clamping force
adequate for front wheel with disc brake. As a result, what may be
good for one wheel installation may allow the wheel to eject after
another installation.

3) Front wheel ejections caused by disc brakes are being prevented by
the retaining lips on fork dropouts. That is, catastrophic
consequences are averted because the axle is kept in the dropouts even
after the QR mechanism has failed. If bikes didn't come with the
so-called lawyer tabs on the dropouts, I think we'd be seeing a lot of
serious injuries caused by the now well-published design flaw that you
have referred to.

Just my 2 cents,

Mykal

"D T W .../\..." <[email hidden]> wrote in message
news:vheCe.1911$Im3.1621@trndny07...

Quoted message said:

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

Quoted message said:

I was thinking of getting a replacement mountain equipped with front and
rear disc brakes, but someone told me some time back about some safety
issue with disc brakes and front wheels falling off?

Is this correct? Is there a safety issue?

Are disc brakes that much better calipers?

Thanks

Been using disks for 3 years. Two different systems on three different
forks, two frames.

AFAIK, my wheels have not detached from the fork without me wanting then
too!

Ask who has returned to caliper brakes after using disks?

I have, to reap the weight savings on an XC bike.

--
Phil, Squid-in-Training

On Sat, 16 Jul 2005 14:26:59 GMT, "The Airman" <[email hidden]>

Quoted message said:

I was thinking of getting a replacement mountain equipped with front and
rear disc brakes, but someone told me some time back about some safety
issue with disc brakes and front wheels falling off?

Is this correct? Is there a safety issue?

Are disc brakes that much better calipers?

Front wheel ejection may happen in certain circumstances. Some
incidents have been traced to improper skewer adjustment, but others
have no such simple explanation. All such events are apparently quite
rare, however. Although the issue has been brought to the attention
of the USCPSC, no need had been established for a recall linked to
disk brake wheel ejection of the last time I checked.

As for whether disk brakes are "better", the answer is situational.
If you do a lot of riding in wet areas, disc brakes may be more useful
due to their greater immunity to problems in that sort of usage. Some
rim brakes tend to lose effectiveness when wet, and some tend to
become rim eaters when wet and/or dirty. In dry, clean conditions, a
disc brake may still be an advantage if you make a lot of long decents
in which you must ride the brakes hard enough that tire overheating
could be an issue. If neither of these is an issue for you, then
there may not be a strong reason for choosing discs. Some people just
like the way they work (from an operational feel standpoint) better
than rim brakes; that's a personal preference issue rather than a
technical performance matter, though.

Rear disc brakes are widely viewed as a waste of money, however, even
when a front disc is deemed useful. YMMV. I've had both, and I find
rear discs to offer no significant advantage. That's just my
preference; others disagree, and have their own reasons.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

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

Quoted message said:

As for whether disk brakes are "better", the answer is situational.
If you do a lot of riding in wet areas, disc brakes may be more useful
due to their greater immunity to problems in that sort of usage. Some
rim brakes tend to lose effectiveness when wet, and some tend to
become rim eaters when wet and/or dirty. In dry, clean conditions, a
disc brake may still be an advantage if you make a lot of long decents
in which you must ride the brakes hard enough that tire overheating
could be an issue. If neither of these is an issue for you, then
there may not be a strong reason for choosing discs. Some people just
like the way they work (from an operational feel standpoint) better
than rim brakes; that's a personal preference issue rather than a
technical performance matter, though.

Disks do not distort the rim, nor are they as likely to have variations in
braking force due to variations of the braking surface; when steering _and_
braking on a hard surface it is possible that those two factors will permit
the rider to come closer to the limit of traction.

jtaylor said:

Disks do not distort the rim,

Good rim brakes don't, either, in most cases.

Quoted message said:

nor are they as likely to have variations in
braking force due to variations of the braking surface; when steering _and_
braking on a hard surface it is possible that those two factors will permit
the rider to come closer to the limit of traction.

From personal experience, some disks tend to warp, and some develop
irregular wear and/or irregular surfaces, all of which can result in
brake pulsation every bit as bad as that of a rim that's not true or
is worn unevenly...and not all disk brakes are even as effective as an
average rim brake in dry conditions. While a *good* disc brake will
be better than a *poor* rim brake, the same holds true in the other
direction. There mere fact that some disc brake systems work well
does not mean that they're all that good, and the fact that some rim
brakes exhibit problems does not mean that they all will. Intelligent
choices are based on individual characteristics and needs, not blanket
assumptions.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Per D T W .../\...:

Quoted message said:

Ask who has returned to caliper brakes after using disks?

I tried to for the rear brake, but my calf kept banging on the v-brake.
--
PeteCresswell