Disk brakes?

I am looking at getting a MTB at around the Deore LX level. Many bikes at
this level use disk brakes. A number of years ago the general consensus
seemed to be that these where heavier, more complicated, put extra strain on
wheels, and did not work as well as cantilevers except in very muddy
conditions. Has this changed to any degree since?

Sticky

I am looking at getting a MTB at around the Deore LX level. Many bikes at
this level use disk brakes. A number of years ago the general consensus
seemed to be that these where heavier, more complicated, put extra strain on
wheels, and did not work as well as cantilevers except in very muddy
conditions. Has this changed to any degree since?

Sticky

Not really.

However (I love that word!), the extra weight is small, the extra
complication relates mainly to the vulnerability of the disk to bending
or warping. Modulation is generally better with rim brakes unless you
go with hydraulic actuation, but that adds a little extra vulnerability
because its more difficult to attempt a repair in a remote location. A
small consideration, really. Removing the wheel can provide the
opportunity for screwing up the pads if the brake lever is pulled,
resulting in overextension of the pads.

The extra strain on wheels is by and large a red herring. If the extra
torque is a problem, then the wheel is marginal for riding anyway. A
hub brake does preclude the radial spoking that some owners find cool.

A disk brake does eliminate a major source of wear on the rim, and
doesn't heat the rim, tire and tube. Excessive heat can be a problem in
some situations.

--
Ted Bennett

Ted Bennett wrote:
I am looking at getting a MTB at around the Deore LX level. Many bikes at
this level use disk brakes. A number of years ago the general consensus
seemed to be that these where heavier, more complicated, put extra strain on
wheels, and did not work as well as cantilevers except in very muddy
conditions. Has this changed to any degree since?

Sticky

Not really.

However (I love that word!), the extra weight is small, the extra
complication relates mainly to the vulnerability of the disk to bending
or warping. Modulation is generally better with rim brakes unless you
go with hydraulic actuation, but that adds a little extra vulnerability
because its more difficult to attempt a repair in a remote location. A
small consideration, really. Removing the wheel can provide the
opportunity for screwing up the pads if the brake lever is pulled,
resulting in overextension of the pads.

The extra strain on wheels is by and large a red herring. If the extra
torque is a problem, then the wheel is marginal for riding anyway. A
hub brake does preclude the radial spoking that some owners find cool.

A disk brake does eliminate a major source of wear on the rim, and
doesn't heat the rim, tire and tube. Excessive heat can be a problem in
some situations.


I was a retro grouch too but having gone to disc brakes I'm a total
convert. No noise, no worn rims, no problems and they WORK! Best thing I
ever did. I use Shimano XT.

Friday

On Jan 26, 10:56 am, Sticky Wicket wrote:
I am looking at getting a MTB at around the Deore LX level. Many bikes at
this level use disk brakes. A number of years ago the general consensus
seemed to be that these where heavier, more complicated, put extra strain on
wheels, and did not work as well as cantilevers except in very muddy
conditions. Has this changed to any degree since?

Sticky

Nope..LX level Vbrakes are better than their discs. If ya gotta have
discs, get hydraulic..which has it's own set of 'issues'.

"Sticky Wicket" wrote in message
...
I am looking at getting a MTB at around the Deore LX level. Many bikes at
this level use disk brakes. A number of years ago the general consensus
seemed to be that these where heavier, more complicated, put extra strain
on
wheels, and did not work as well as cantilevers except in very muddy
conditions. Has this changed to any degree since?

Sticky


There was a long discussion about how a boutique alloy skewer is not strong
enough to counter the massive downward force a disc brake causes on the
front wheel, potentially causing the front wheel to fall off the fork ends.
Whether or not it's true, it did contribute to my already retro-grouchy
dislike for disk brakes.

It's a shame that suspension fork nowadays (and mtb frames) don't even come
with brake studs. There is a reason I haven't bought a mountain frame or
fork newer than '04. V's have a plenty of stopping power for me.

On Fri, 26 Jan 2007 19:18:26 +0000, Ted Bennett wrote:


I am looking at getting a MTB at around the Deore LX level. Many bikes at
this level use disk brakes. A number of years ago the general consensus
seemed to be that these where heavier, more complicated, put extra strain on
wheels, and did not work as well as cantilevers except in very muddy
conditions. Has this changed to any degree since?

Sticky

Not really.

However (I love that word!), the extra weight is small, the extra
complication relates mainly to the vulnerability of the disk to bending
or warping. Modulation is generally better with rim brakes unless you
go with hydraulic actuation, but that adds a little extra vulnerability
because its more difficult to attempt a repair in a remote location. A
small consideration, really. Removing the wheel can provide the
opportunity for screwing up the pads if the brake lever is pulled,
resulting in overextension of the pads.

The extra strain on wheels is by and large a red herring. If the extra
torque is a problem, then the wheel is marginal for riding anyway. A
hub brake does preclude the radial spoking that some owners find cool.

A disk brake does eliminate a major source of wear on the rim, and
doesn't heat the rim, tire and tube. Excessive heat can be a problem in
some situations.

I put Avid BB7 Mechanical Disks on my Rockhopper and haven't regretted it.
I get a little brake squeel once in a while but that doesn't affect
their stopping power which I feel is superior to rim brakes especially
in wet weather.
From what I've been told the BB7's modulate as well as hydraulic disks.
I'll have an opinion on that soon as the bike I have on layaway
is equipped with Avid Juicy 5 hydraulic disks.
and changing brake pads is a lot easier than on rim brakes.
One other small plus is not having to wipe your rims down after
each ride.
If you ride in wet and/or muddy conditions discs are the way to go.
I'll never use rim brakes on my mountain bike(s) again.

Bellsouth Ijit 2.0 wrote:

There was a long discussion about how a boutique alloy skewer is not strong
enough to counter the massive downward force a disc brake causes on the
front wheel, potentially causing the front wheel to fall off the fork ends.
Whether or not it's true, it did contribute to my already retro-grouchy
dislike for disk brakes.


Not true, at least on most US-market bikes. The reason is the "lawyer
lips" that are designed to keep the front wheel attached even if the QR
is flipped open. 15 years ago I could flip the front QR and the wheel
would fall right out the drops--but now, aside from the "laywer lips", a
couple bikes I've bought have arrived with the fork blades spayed
outwards a few mm--making inadvertent disconnection even more unlikely.
You have to flip open the QR and then you still have to fight the fork
blades to unscrew the QR for a bit. --I'm not certain US needed both
these "features" but we are getting them anyway. :\

I haven't tried a big disk on a MTB [hard-use] fork however; disk brakes
came along just as I was losing interest in hardcore MTB riding. Back
then a disk brake was a $500 custom-shop gadget that would only mount to
a $700 Manitou fork....
~

"Sticky Wicket" wrote in message
...
I am looking at getting a MTB at around the Deore LX level. Many bikes at
this level use disk brakes. A number of years ago the general consensus
seemed to be that these where heavier, more complicated, put extra strain
on
wheels, and did not work as well as cantilevers except in very muddy
conditions. Has this changed to any degree since?

Sticky


Plus points for discs (principally hydraulics):
No rim wear
work in wet/mud
don't eat pads in a single wet ride
better modulation than Vs
less/no adjustment as pads wear
no 'cable' adjustments (open systems)
potentially fewer problems if you buckle a wheel
possibly easier routing for rear brake on full-suspension frames

Plus points for Vs:
cheaper
lighter
no nasty hydraulic fluids
Possibly simpler to fix in the field (I can't actually remember the last
time I had to do major brake surgery in the field though)

Here in the UK (it rains) discs are very popular. Plenty of shops doing a
good trade in converting bikes from V to disc. Hope seem to be doing very
nicely!

Skippy
E&OE

Sticky Wicket wrote:
I am looking at getting a MTB at around the Deore LX level. Many bikes at
this level use disk brakes. A number of years ago the general consensus
seemed to be that these where heavier, more complicated, put extra strain on
wheels, and did not work as well as cantilevers except in very muddy
conditions. Has this changed to any degree since?

Sticky

stop listening to retrogrouches and try them. if you're not prepared to
put up with better braking, better wear in the wet, better bent wheel
tolerance, better performance in the wet and [with hydraulics] better
modulation, then yes, cantilevers are for you.

On Sat, 27 Jan 2007 06:50:53 -0600, DougC wrote:

Not true, at least on most US-market bikes. The reason is the "lawyer
lips" that are designed to keep the front wheel attached even if the QR
is flipped open.

Is there a Specification for the lawyer lips in the USA? The UK, and I
think ISO, Spec reads:

"9.4.4.2 Wheel retention with open quick-release
With the quick-release mechanism fully open and the brake system
disconnected or released, the wheel shall not detach from the fork
when a force of 100N is applied to the wheel radially outwards and
in line with the drop out slots."

To save you reaching for your calculator, 100N is 22.5lbf, or less than
the weight of most bikes. So the lawyer lips are not intended to hold
against the weight of the bike, let alone the forces created by braking.


Mike