Can Disk Brakes flip you over the handle bars?

"Kerry Montgomery" wrote in message
m...

Jobst and Nate,
Just to set some common ground - here is what I think a vented disk brake
rotor looks like:
http://images.outdoorinteractive.net/mgen/530211_oi.jpg

Yeah, I am coming to the conclusion that Jobst doesn't actually understand
the normal definition of 'vented' - that used by most auto-parts suppliers.

Your picture agrees with me and pretty much everybody else.

cheers,
clive

"Nate Nagel" wrote in message
...
Clive George wrote:
"Nate Nagel" wrote in message
...

This is what I was alluding to when I mentioned the improved pedal feel
of drums - the vacuum booster commonly used does make for a far less
direct feel on the brake pedal.


You might find driving a power-braked car amusing - on a proper citroen,
the pedal doesn't move (noticably), but the braking is still proportional
to how hard you press. Coming from an over-assisted conventional car was
an interesting reminder of the difference.

Any modern car equipped with disc brakes. In my driveway, a Chevy
Impala (icky company car) a Porsche 944 and a Ford F-150. All have
vented discs, at least on the front.


Many over here don't have vented. My CX had them (all round :-) ), but
nothing else I've owned. The stuff you've just mentioned comes under
"bigger or faster than normal". Of course with the weight inflation of
cars, they're getting rather more common...

If you'd consider any of those cars "faster than normal" I have the
greatest sympathy for you.

I did carefully say "bigger" first.

Of course Vlad the Impala and the pickup truck are also quite large, and
only one of those two has a good reason for being so. A 944 has many
redeeming qualities, but sparkling acceleration isn't one of them.

Is it broken? 944 wasn't actually _that_ slow, even in N/A form. 137mph top
speed isn't too bad for 1982, and is still faster than many cooking model
cars.

Oddly enough, likely the fastest car I own (I don't know for sure, I
haven't fully tested its capabilities) is also the one with four wheel
drum brakes.

I did have an amusing time recently reading about USian muscle cars - with
hundreds of BHP, but engineered for the 1/4 mile rather than actual speed,
as could be seen by the gearing they came with. Probably a good thing though
given the handling and braking :-)

cheers,
clive

"Tom Sherman" wrote in message
...
[...]
Back in the early days of the 20th Century recumbent revival (e.g.
Hypercycle, the never produced Avatar 1000,) the designers mistakenly
thought that some heel/wheel overlap needed to be avoided. Therefore, the
boom was made very long and the rider was seated almost over the front
wheel. This led to too flexible booms which made climbing and acceleration
poor, poor handling - especially when hitting bumps at speed , and the
bike rotating forward about the front wheel contact patch under hard
braking.

Modern short=wheelbase recumbent sensibly trade off some heel overlap for
proper weight distribution and have none of the above flaws. However, some
of the "experts" tried the earlier designs 25 or 30 years ago and have
closed their minds to later improvements.

Even so, SWB recumbents do not handle well and tend to be squirrely. They
are fine for around town for a few hours, but they are the pits on day long
rides. Also, heel overlap is not a good idea. Sooner or later it will trip
you up.

Regards,

Ed Dolan the Great - Minnesota
aka
Saint Edward the Great - Order of the Perpetual Sorrows - Minnesota

Clive George wrote:
"Nate Nagel" wrote in message
...

Clive George wrote:

"Nate Nagel" wrote in message
...

This is what I was alluding to when I mentioned the improved pedal
feel of drums - the vacuum booster commonly used does make for a far
less direct feel on the brake pedal.



You might find driving a power-braked car amusing - on a proper
citroen, the pedal doesn't move (noticably), but the braking is still
proportional to how hard you press. Coming from an over-assisted
conventional car was an interesting reminder of the difference.

Any modern car equipped with disc brakes. In my driveway, a Chevy
Impala (icky company car) a Porsche 944 and a Ford F-150. All have
vented discs, at least on the front.



Many over here don't have vented. My CX had them (all round :-) ),
but nothing else I've owned. The stuff you've just mentioned comes
under "bigger or faster than normal". Of course with the weight
inflation of cars, they're getting rather more common...


If you'd consider any of those cars "faster than normal" I have the
greatest sympathy for you.


I did carefully say "bigger" first.

Of course Vlad the Impala and the pickup truck are also quite large,
and only one of those two has a good reason for being so. A 944 has
many redeeming qualities, but sparkling acceleration isn't one of them.


Is it broken? 944 wasn't actually _that_ slow, even in N/A form. 137mph
top speed isn't too bad for 1982, and is still faster than many cooking
model cars.

I don't think they had quite as much power over here as in Europe...
mine's an 88, so had 150-something HP from the factory, and I doubt it's
picked up any extra over the years I might have a *slightly* warped
perspective though, as my previous ride was a GTI 1.8T which had Hand of
God Torque(tm) and although it didn't handle as well would just flat out
destroy any 944 (NA) in a straight line.

I would really like to try a turbo 944 some day, but budget etc.


Oddly enough, likely the fastest car I own (I don't know for sure, I
haven't fully tested its capabilities) is also the one with four wheel
drum brakes.


I did have an amusing time recently reading about USian muscle cars -
with hundreds of BHP, but engineered for the 1/4 mile rather than actual
speed, as could be seen by the gearing they came with. Probably a good
thing though given the handling and braking :-)

yeah, some of the larger ones were borderline irresponsible, e.g.
Hemi-powered midsize MoPars with disc brakes *optional* - a Studebaker
isn't so bad as it is a fairly light car and their drum brakes were
better than most. Handling was never a big priority as even most
"sporty" American cars were really primarily people haulers and long
distance tourers; if you wanted to go around corners fast you needed to
look to something European. The Corvette being the only real notable
mass-market exception that comes to mind...

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Edward Dolan wrote:
"Tom Sherman" wrote in message
...
[...]
Back in the early days of the 20th Century recumbent revival (e.g.
Hypercycle, the never produced Avatar 1000,) the designers mistakenly
thought that some heel/wheel overlap needed to be avoided. Therefore, the
boom was made very long and the rider was seated almost over the front
wheel. This led to too flexible booms which made climbing and acceleration
poor, poor handling - especially when hitting bumps at speed , and the
bike rotating forward about the front wheel contact patch under hard
braking.

Modern short=wheelbase recumbent sensibly trade off some heel overlap for
proper weight distribution and have none of the above flaws. However, some
of the "experts" tried the earlier designs 25 or 30 years ago and have
closed their minds to later improvements.

Even so, SWB recumbents do not handle well and tend to be squirrely. They
are fine for around town for a few hours, but they are the pits on day long
rides.

My short-wheelbase recumbents (RANS Rocket, Earth Cycles Sunset
Lowracer) are easy to ride, even after I have hammered to the point of
exhaustion on a double metric century.

Also, heel overlap is not a good idea. Sooner or later it will trip
you up.

Not a big deal as long as there is nothing for the crank to hit. Crank
to wheel overlap can dump you in a hurry. Of course, that can only
happen at low speed, and a low speed fall on a recumbent is trivial
compared to doing the same on an upright.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

Nate Nagel wrote:
[...] The three major shortcomings
of drum brakes in general are 1) brakes often undersized for the
vehicle, exacerbating other problems (not an issue on my car, but, say,
the 9" front drums on an old Dart are an insult to common sense.)[...]

I drove the early 1970's Plymouth sibling for a bit, and the brakes were
about as effective as using just the hand brake on a proper automobile.
The only thing worse was the steering, which felt like a wheel mounted
to a bearing, with absolutely no feedback. The rest of the car was
hardly better.

No wonder Chrysler would have gone bankrupt without corporate welfare.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

aka Jobst Brandt wrote:
[...]
That's why heavy trucks still use drum brakes, drums having large
surface to reject heat by forced convection. Highways have long dual
tired skid marks because the response to brake application cannot be
well controlled with drum brakes.[...]

Herr Brandt must not have driven a 2002-2005 Honda Civic, which has rear
drum brakes but exhibits none of the ills that Brandt claims are
inherent to drums.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

aka Jobst Brandt wrote:
[...]
OK! You keep making these claims and show no reason or reference for
them. Just inspect BMW cars and note that even their large "sport
cars"do not have holes in the disks.[...]

Like these vented rotors for BMW's?
http://www.global-b2b-network.com/direct/dbimage/10318396/Brake_Rotor_For_BMW_and_BENZ.jpg

No holes on the braking surface, but radial holes between the surfaces.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

Nate Nagel wrote:
Clive George wrote:
[...]
I did have an amusing time recently reading about USian muscle cars -
with hundreds of BHP, but engineered for the 1/4 mile rather than
actual speed, as could be seen by the gearing they came with. Probably
a good thing though given the handling and braking :-)

yeah, some of the larger ones were borderline irresponsible, e.g.
Hemi-powered midsize MoPars with disc brakes *optional* - a Studebaker
isn't so bad as it is a fairly light car and their drum brakes were
better than most. Handling was never a big priority as even most
"sporty" American cars were really primarily people haulers and long
distance tourers; if you wanted to go around corners fast you needed to
look to something European. The Corvette being the only real notable
mass-market exception that comes to mind...

Not mass market by any stretch of the imagination, but a USian car with
a big V-8 that likely gave Signore Ferrari sleepless nights:
http://www.legendarymotorsport.com/Portals/0/Good.jpg.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

Clive George wrote:
"Nate Nagel" wrote in message
...

This is what I was alluding to when I mentioned the improved pedal
feel of drums - the vacuum booster commonly used does make for a far
less direct feel on the brake pedal.

You might find driving a power-braked car amusing - on a proper citroen,
the pedal doesn't move (noticably), but the braking is still
proportional to how hard you press. Coming from an over-assisted
conventional car was an interesting reminder of the difference.

Any modern car equipped with disc brakes. In my driveway, a Chevy
Impala (icky company car) a Porsche 944 and a Ford F-150. All have
vented discs, at least on the front.

Many over here don't have vented. My CX had them (all round :-) ), but
nothing else I've owned. The stuff you've just mentioned comes under
"bigger or faster than normal". Of course with the weight inflation of
cars, they're getting rather more common...

Bigger and faster than normal for the EU, but not for NA.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful