Antilock braking for bicycles

Wouldn't it be great if you could backpedal your multigear bike and get braking
that would ease the front brake the instant the rear tire started to lift?

I built such a bike in about 1992.

It was a Shimano three speed coaster brake hub, on the cheapest frame I could
get, salvaged from the cleanout of the Hollybrooke condominium bicycle storage
room.

The torque arm was supported by about a 10 x 25 mm cartridge bearing which in
turn was spaced by a shim made from a polyethylene milk jug cap, the kind that
you have to tear the tab off of to open. The rearranged axle lock nuts applied
force from the outside through the now mobilized arm to the large (50mm)
bearing of tiny (individual?) balls that was the left hub cup and cone. The
cartridge bearing was therefore used at extrememly _low_ PV in its designed
function, and at high P, zero V in its thrust ability. Such bearings do have
thrust ability.

The braking action was overly responsive in first, about right in second, and
had a strange behavior in third. I'd say third on that bike was for no-traffic,
no-hill conditions only, but I did ride it 14 miles from Greenwood Drive to
Pickett Rd. to the bike shop and it did work, and I didn't have any accidents.
You could instantly snap the shifter to any brake geometry you'd care so all in
all it was fairly safe.

Well, now I am building the wide range Thunderbolt and I would like to get rid
of this one of about 120 boxes I have lying around. If you'd like to have a go,
all the parts needed are in the box. Sorry, the frame is long gone. No spokes.
No rims. Just the magic hub, fittings, cabling, and caliper brake, a good one
if I remember correctly.

I'd mount the shifter on the seat post and leave the handlebars gloriously
bare, but your taste is not my taste.



My physics project at NVCC:
Google Groups, then "dgoncz" and some of:
ultracapacitor bicycle fluorescent flywheel inverter

4-1-9 Fraud
http://www.secretservice.gov/electronic_evidence.shtml

Doug Goncz writes:

Wouldn't it be great if you could backpedal your multigear bike and
get braking that would ease the front brake the instant the rear
tire started to lift?

Considering that few riders ever brake hard enough to raise the rear
wheel, this is a solution looking for a problem. When people go over
the bars, it is not from braking too hard, but rather from not bracing
rider weight with the arms to keep from sliding off the saddle. The
bicycle subsequently overturns when the rider's legs hit the
handlebar, not from excess braking.

http://draco.acs.uci.edu/rbfaq/FAQ/9.36.html

Jobst Brandt

On the few occasions that I had to brake that hard, I throw my butt as
far back behind the saddle as is reasonably possible and still remain in
control. This helps hold the rear wheel on the ground.

Not perfect, of course. Nothing is. But my cycling brain knows enough
that the rear tire starting to skid is a sure sign that there is no
longer enough weight to safely hold the rear wheel on the ground. At
which point I let up slightly on the front brake.

So far me, rapping on my bed frame, I have not experienced the event
lovingly known as a "face plant".

"May you have the wind at your back.
And a really low gear for the hills!"

Chris Zacho ~ "Your Friendly Neighborhood Wheelman"

Chris'Z Corner
http://www.geocities.com/czcorner

Doug Goncz wrote:
Wouldn't it be great if you could backpedal your multigear bike and get
braking that would ease the front brake the instant the rear tire
started to lift?
I built such a bike in about 1992.
It was a Shimano three speed coaster brake hub, on the cheapest frame I
could get, salvaged from the cleanout of the Hollybrooke condominium
bicycle storage room.
The torque arm was supported by about a 10 x 25 mm cartridge bearing
which in turn was spaced by a shim made from a polyethylene milk jug
cap, the kind that you have to tear the tab off of to open. The
rearranged axle lock nuts applied force from the outside through the now
mobilized arm to the large (50mm) bearing of tiny (individual?) balls
that was the left hub cup and cone. The cartridge bearing was therefore
used at extrememly _low_ PV in its designed function, and at high P,
zero V in its thrust ability. Such bearings do have thrust ability.
The braking action was overly responsive in first, about right in
second, and had a strange behavior in third. I'd say third on that bike
was for no-traffic, no-hill conditions only, but I did ride it 14 miles
from Greenwood Drive to Pickett Rd. to the bike shop and it did work,
and I didn't have any accidents. You could instantly snap the shifter to
any brake geometry you'd care so all in all it was fairly safe.
Well, now I am building the wide range Thunderbolt and I would like to
get rid of this one of about 120 boxes I have lying around. If you'd
like to have a go, all the parts needed are in the box. Sorry, the frame
is long gone. No spokes. No rims. Just the magic hub, fittings, cabling,
and caliper brake, a good one if I remember correctly.
I'd mount the shifter on the seat post and leave the handlebars
gloriously bare, but your taste is not my taste.
My physics project at NVCC: Google Groups, then "dgoncz" and some of:
ultracapacitor bicycle fluorescent flywheel inverter
4-1-9 Fraud http://www.secretservice.gov/electro...ce.shtmlhttp:-
//www.secretservice.gov/electronic_evidence.shtml


Doug

Doesn’t quite fit the definition of antilock brakes. Locking occurs whe
the tires are not spinning, or a mild locking related phenomenon know
as wheel slip occurs when the tire is moving at different speed than th
ground beneath it (wheel is slower than ground in braking)

Antilock brakes release brakes that are moving slower than the pavemen
beneath the tires. Automotive antilock brakes release and reapply brake
up to fifty times per second, at least that was typical in 1989-199
time frame when I was writing antilock brake controller software as a
engineer at General Motors- I haven’t really kept up with the ABS brak
technology since I left General Motors in 1993 so it’s conceivabl
release cycles are faster nowdays

You can endo without locking the front, just decel fast enough to creat
a moment about the front contact patch caused by the decel of the rider-bike
position greater than the moment behind the patch caused by the gravity
position of the rider-bike

I think you’ve omitted details of your Anti-Flip Braking (AFB?) system

Was your 3 speed hub on the rear with movement of the arm operating
linkage to the front to release the brake

As for antilock bicycle brakes- here’s an all mechanical ABS brak
system: http://www.blackbirdsf.org/brake_obs...s/brovedani.jp
http://www.blackbirdsf.org/brake_obs...ovedani_man.pd
www.blackbirdsf.org/brake_obscura


-works by using a roller cam on the rim to lift the pads periodically
Since this manufacturer is a supplier of automotive brake components
I’m not sure if this was produced for the bike market or was merely
concept demonstration by someone in the ABS field

Unfortunately, modulation is only wheelspeed dependent


-

Jobst Brandt wrote:
Doug Goncz writes:
Wouldn't it be great if you could backpedal your multigear bike and
get braking that would ease the front brake the instant the rear tire
started to lift?
Considering that few riders ever brake hard enough to raise the rear
wheel, this is a solution looking for a problem. When people go over the
bars, it is not from braking too hard, but rather from not bracing rider
weight with the arms to keep from sliding off the saddle. The bicycle
subsequently overturns when the rider's legs hit the handlebar, not from
excess braking.
http://draco.acs.uci.edu/rbfaq/FAQ/9...cs.uci.edu/rb-
faq/FAQ/9.36.html
Jobst Brandt


Endo’s and rear tire lifts are a result of having a moment about th
front contact patch caused by the bike-rider mass times the decel rat
times the center or gravity (cg) height over the ground exceeding th
competing moment caused by the mass times the distance the cg trails th
front contact patch. Bracing harder on the handlebars transfers th
force of the decelling rider to the handlebars, but does not change th
location of the rider-bike combination’s cg nor remove it from th
system. Somewhere between a .5 and .65G decell, road bikes endo

I’ve endoed many times on my road bikes never having left my seat

Short wheelbase recumbents flip under braking with the rider not eve
leaving the seat, bracing with the handlebars has little to do wit
whether the rider would leave the seat on a swb bent during braking

Another way of looking at it is when you brace with the arms on th
handlebars, you are forcing the handlebars forward about the contac
patch. The same rider mass that forces the rear down under gravity i
inertia resisting velocity change under braking and forcing th
handlebars forward of the front contact patch


-

meb wrote:

Doesn’t quite fit the definition of antilock brakes. Locking occurs when
the tires are not spinning, or a mild locking related phenomenon known
as wheel slip occurs when the tire is moving at different speed than the
ground beneath it (wheel is slower than ground in braking).

Antilock brakes release brakes that are moving slower than the pavement
beneath the tires. Automotive antilock brakes release and reapply brakes
up to fifty times per second, at least that was typical in 1989-1991
time frame when I was writing antilock brake controller software as an
engineer at General Motors- I haven’t really kept up with the ABS brake
technology since I left General Motors in 1993 so it’s conceivable
release cycles are faster nowdays.

You can endo without locking the front, just decel fast enough to create
a moment about the front contact patch caused by the decel of the rider-bike-
position greater than the moment behind the patch caused by the gravity-
position of the rider-bike.


I think you’ve omitted details of your Anti-Flip Braking (AFB?) system.

Was your 3 speed hub on the rear with movement of the arm operating a
linkage to the front to release the brake?

As for antilock bicycle brakes- here’s an all mechanical ABS brake
system: http://www.blackbirdsf.org/brake_obs.../brovedani.jpg
http://www.blackbirdsf.org/brake_obs...vedani_man.pdf
www.blackbirdsf.org/brake_obscura/



-works by using a roller cam on the rim to lift the pads periodically.
Since this manufacturer is a supplier of automotive brake components,
I’m not sure if this was produced for the bike market or was merely a
concept demonstration by someone in the ABS field.

Unfortunately, modulation is only wheelspeed dependent.

A very simple mechanical Anti-Flip braking system was illustrated in the
Bicycling Science book by Wilson and Whitt. That system works by having
the rider only have direct control over the rear brake which operates in
the usual fashion on the rim but is mounted on a spring-loaded sliding
mount so that it moves forward as a result of engaging the rear rim.
There is a cable attached to the moving rear brake mechanism that then
pulls on the front brake which provides the bulk of the stopping power.

So the front brake cable is pulled by the reaction force on the
rear brake and the moment the rear wheel starts to leave the ground this
reaction force is reduced and that partially releases the front brake to
prevent a flip.

The rider can therefore pull as hard as he wants on the brake lever and
the bicycle will automatically stop with a deceleration that is just on
the verge of lifting the rear wheel off the ground. Of course he
better have a firm grasp on the handlebars so he doesn't fly off the
bike anyway. The leverage of the cable pull on the front brake can be
adjusted depending on how much of a 'power brakes' effect is desired by
the rider.

Peter wrote:
meb wrote:
Doesn’t quite fit the definition of antilock brakes. Locking occurs
when the tires are not spinning, or a mild locking related phenomenon
known as wheel slip occurs when the tire is moving at different speed
than the ground beneath it (wheel is slower than ground in braking).

Antilock brakes release brakes that are moving slower than the
pavement beneath the tires. Automotive antilock brakes release and
reapply brakes up to fifty times per second, at least that was typical
in 1989-1991 time frame when I was writing antilock brake controller
software as an engineer at General Motors- I haven’t really kept up
with the ABS brake technology since I left General Motors in 1993 so
it’s conceivable release cycles are faster nowdays.

You can endo without locking the front, just decel fast enough to
create a moment about the front contact patch caused by the decel of
the rider-bike- position greater than the moment behind the patch
caused by the gravity- position of the rider-bike.


I think you’ve omitted details of your Anti-Flip Braking (AFB?)
system.

Was your 3 speed hub on the rear with movement of the arm operating a
linkage to the front to release the brake?

As for antilock bicycle brakes- here’s an all mechanical ABS brake
system: http://www.blackbirdsf.org/brake_obscur-
http://www.blackbirdsf.org/brake_obscur-
a/images/brovedani.jpg http://www.blackbirdsf.org/brake_o-
http://www.blackbirdsf.org/brake_o- bscura/brovedani_man.pdf
www.blackbirdsf.org/brake_obscura/



-works by using a roller cam on the rim to lift the pads periodically.
Since this manufacturer is a supplier of automotive brake components,
I’m not sure if this was produced for the bike market or was merely a
concept demonstration by someone in the ABS field.

Unfortunately, modulation is only wheelspeed dependent.
A very simple mechanical Anti-Flip braking system was illustrated in the
Bicycling Science book by Wilson and Whitt. That system works by having
the rider only have direct control over the rear brake which operates in
the usual fashion on the rim but is mounted on a spring-loaded sliding
mount so that it moves forward as a result of engaging the rear rim.
There is a cable attached to the moving rear brake mechanism that then
pulls on the front brake which provides the bulk of the stopping power.
So the front brake cable is pulled by the reaction force on the rear
brake and the moment the rear wheel starts to leave the ground this
reaction force is reduced and that partially releases the front brake to
prevent a flip.
The rider can therefore pull as hard as he wants on the brake lever and
the bicycle will automatically stop with a deceleration that is just on
the verge of lifting the rear wheel off the ground. Of course he better
have a firm grasp on the handlebars so he doesn't fly off the bike
anyway. The leverage of the cable pull on the front brake can be
adjusted depending on how much of a 'power brakes' effect is desired by
the rider.


Peter-Impressive approach

I assume you're referring to the Calderazzo brake system shown on pp210
212 or the the 1982 edition of Bicycle Science

Was this system ever manufactured

I think this might work also work well when trying to control 4 brake
with 2 hands on my quadribent

Thank


-

meb wrote:

Peter wrote:
meb wrote:
As for antilock bicycle brakes- here’s an all mechanical ABS brake
system: http://www.blackbirdsf.org/brake_obscur-
http://www.blackbirdsf.org/brake_obscur-
a/images/brovedani.jpg http://www.blackbirdsf.org/brake_o-
http://www.blackbirdsf.org/brake_o- bscura/brovedani_man.pdf
www.blackbirdsf.org/brake_obscura/



-works by using a roller cam on the rim to lift the pads periodically.
Since this manufacturer is a supplier of automotive brake components,
I’m not sure if this was produced for the bike market or was merely a
concept demonstration by someone in the ABS field.

Unfortunately, modulation is only wheelspeed dependent.
A very simple mechanical Anti-Flip braking system was illustrated in the
Bicycling Science book by Wilson and Whitt. That system works by having
the rider only have direct control over the rear brake which operates in
the usual fashion on the rim but is mounted on a spring-loaded sliding
mount so that it moves forward as a result of engaging the rear rim.
There is a cable attached to the moving rear brake mechanism that then
pulls on the front brake which provides the bulk of the stopping power.
So the front brake cable is pulled by the reaction force on the rear
brake and the moment the rear wheel starts to leave the ground this
reaction force is reduced and that partially releases the front brake to
prevent a flip.
The rider can therefore pull as hard as he wants on the brake lever and
the bicycle will automatically stop with a deceleration that is just on
the verge of lifting the rear wheel off the ground. Of course he better
have a firm grasp on the handlebars so he doesn't fly off the bike
anyway.

Peter-Impressive approach.

I assume you're referring to the Calderazzo brake system shown on pp210-
212 or the the 1982 edition of Bicycle Science.

That's the one.

Was this system ever manufactured?

I don't believe so, but the prototype was reported to work well until
the fork failed from the stress of too many demonstrations of high-
speed stops.

I think this might work also work well when trying to control 4 brakes
with 2 hands on my quadribent.


There was an article in Bicycling a couple decades or so ago with a similar
arrangement on a tandem that was used to increase braking power rather
than anti-flip. It used a rear hub brake as the actuating mechanism and
attached a cable from the reaction arm of the hub brake to a rim brake.
In that particular case the rim brake was also on the rear wheel and the
purpose was to control both brakes with a single pull and to substantially
multiply the force applied to the rim brake. The design looked easier
to construct than the Calderazzo one since the hub brake already has the
reaction arm.

meb wrote:

...
Short wheelbase recumbents flip under braking with the rider not even
leaving the seat, bracing with the handlebars has little to do with
whether the rider would leave the seat on a swb bent during braking....

If the seat (and therefore combined rider/bicycle center of mass) is low
enough, the SWB recumbent will not have enough front wheel traction to
overturn. I can easily lock both front wheels on my trike [1] without
the chainring hitting the ground. The same is true for my lowracer [2],
but in this case locking the front wheel leads to a loss of balance.

[1] http://www.ihpva.org/incoming/2002/df1a.jpg
[2] http://www.ihpva.org/incoming/2002/sunset/Sunset001.jpg

Tom Sherman - Quad Cities (Illinois Side)

From: Peter

A very simple mechanical Anti-Flip braking system was illustrated in the
Bicycling Science book by Wilson and Whitt.

I have this book.

That system works by having
the rider only have direct control over the rear brake

That's what I've got here.

it moves forward as a result of engaging the rear rim.
There is a cable attached to the moving rear brake mechanism that then
pulls on the front brake which provides the bulk of the stopping power.

Yes. That's how it works. And when the "move forward" is replaced by the torque
arm, you find you have variable ratios.

What I'm wondering is, if there's a planetary hub that provides the same pedal
to front brake action in all gears, so I can try this again.

I drilled a hole in the torque arm and installed a cable adjuster holder. I
screwed the cable adjuster all the way in. Instead of sheating on the run side,
the cable head was retained in the large opening of the adjuster on the down
side. The bare cable went to another adjuster--how did I hook that up, then
sheathing and cable went to operate the front brake conventionally.

Hmm. I don't remember. Maybe it was a seat bolt brake adjuster hanger, a
spacer, and a long seat bolt, hanging to the left side.

It provided solid braking in second gear.



My physics project at NVCC:
Google Groups, then "dgoncz" and some of:
ultracapacitor bicycle fluorescent flywheel inverter

4-1-9 Fraud
http://www.secretservice.gov/electronic_evidence.shtml