Sacramento fixed-gear bikes: braking the law

wrote:
Fixies are a fad too. There is no defensible reason why they can't
have hand brakes in addition to the back-pressure method of stopping.

The fixie defenders will maintain that "I have the leg skills to stop
just as well as somebody with front and rear hand brakes".

I think half of their belief is a lack of understanding of the physics
of bicycle braking, and the other half is a machismo-inspired
unwillingness to understand it.

With no front brake, one needs twice the time and twice the distance to
stop, compared to somebody with a front brake. If you are riding on a
paved surface and you have a front brake, you don't need your rear brake
*at all*.

--
K.

Lang may your lum reek.

On 1 Nov, 17:46, (Király) wrote:

The fixie defenders will maintain that "I have the leg skills to stop
just as well as somebody with front and rear hand brakes".

Clearly false.


I think half of their belief is a lack of understanding of the physics
of bicycle braking, and the other half is a machismo-inspired
unwillingness to understand it.

With no front brake, one needs twice the time and twice the distance to
stop, compared to somebody with a front brake.

Not quite that bad. Because a track bikes rear wheel is generally
tucked in as close as chain adjustment allows to the seat tube, when
the rider shift his weight backward with a locked wheel on a dry road
surface the stopping distance is generally shorter than most childs
bikes. If the rider has enhanced skills, he may brake harder than
this by sliding side ways, putting the braking tyre patch further
forward in relation to his CofG. This is almost as good as maximum
braking with a front brake but is severe on the tyre and you may not
have the room to perform the stunt when you really need to use it.

*If you are riding on a
paved surface and you have a front brake, you don't need your rear brake
*at all*.

--
K.

Lang may your lum reek.

In article ,
=?windows-1252?Q?Tom_Sherman_=B0=5F=B0?= writes:
"Ablang" ? wrote:
Unbelievable isn't it?

Sacramento fixed-gear bikes: braking the law
Sacramento police recently began targeting illegal fixed-gear bikes.
But are the brake-free rides really dangerous, or are cops simply
going after a counterculture scene?[...]

"Counterculture" is really just another strict conformist group. There
is no reason not to have a front brake [1] other than wanting to look
"hip". I find the whining of these over-grown brats about being ticketed
to be amusing.

[1] The amount of money spent on these bicycles indicates that poverty
is not an excuse.

I don't recall during the course of my half-century+ lifetime
bicycle riding evoking so much law enforcement as it does now.

Perhaps it indicates cyclists are finally becoming a known
quantity in the collective mind of the general public.


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

On 2 Nov, 05:41, Phil W Lee phil(at)lee-family(dot)me(dot)uk wrote:
(Király) considered Sun, 01 Nov 2009 17:46:28 GMT
the perfect time to write:

wrote:
* *Fixies are a fad too. *There is no defensible reason why they can't
have hand brakes in addition to the back-pressure method of stopping. *

The fixie defenders will maintain that "I have the leg skills to stop
just as well as somebody with front and rear hand brakes".

I think half of their belief is a lack of understanding of the physics
of bicycle braking, and the other half is a machismo-inspired
unwillingness to understand it.

With no front brake, one needs twice the time and twice the distance to
stop, compared to somebody with a front brake. *If you are riding on a
paved surface and you have a front brake, you don't need your rear brake
*at all*.

It's worse than that - you can get far more braking from the front
wheel, so you lose much more than half the braking, and therefore need
much more than twice the stopping distance,
Somewhere between 3 and 4 times the distance, in fact.

On a wet road with a slick tyre. On a dry road with a reasonable (not
skinny) tyre, rear braking alone can be acceptable if body weight is
shifted back. You cannot shift bodyweight as far back when holding
onto brake levers as is possible on a track bike. On a road with
little camber, the rider only needs to hold the stem to effect
steering when braking, which means his weight can be further back. So
'in fact' it appears your assumptions of braking performance are
clearly ill-founded.

On Nov 1, 10:19*am, wrote:
Tom Sherman °_° wrote:

Sacramento fixed-gear bikes: braking the law
Sacramento police recently began targeting illegal fixed-gear bikes.
But are the brake-free rides really dangerous, or are cops simply
going after a counterculture scene?[...]

They're dangerous and illegal.

The real story would be a psychological profile piece on people that
consistently need to set themselves up to be victims as a component of
their "scene".

I mean--would a drunk driver have a leg to stand on if he demanded
respect because he was supporting the troops by driving a Cavalier?

Hahahaha!

On 2 Nov, 18:17, Phil W Lee phil(at)lee-family(dot)me(dot)uk wrote:
thirty-six considered Mon, 2 Nov 2009 04:23:11
-0800 (PST) the perfect time to write:



On 2 Nov, 05:41, Phil W Lee phil(at)lee-family(dot)me(dot)uk wrote:
(Király) considered Sun, 01 Nov 2009 17:46:28 GMT
the perfect time to write:

wrote:
* *Fixies are a fad too. *There is no defensible reason why they can't
have hand brakes in addition to the back-pressure method of stopping. *

The fixie defenders will maintain that "I have the leg skills to stop
just as well as somebody with front and rear hand brakes".

I think half of their belief is a lack of understanding of the physics
of bicycle braking, and the other half is a machismo-inspired
unwillingness to understand it.

With no front brake, one needs twice the time and twice the distance to
stop, compared to somebody with a front brake. *If you are riding on a
paved surface and you have a front brake, you don't need your rear brake
*at all*.

It's worse than that - you can get far more braking from the front
wheel, so you lose much more than half the braking, and therefore need
much more than twice the stopping distance,
Somewhere between 3 and 4 times the distance, in fact.

On a wet road with a slick tyre. *On a dry road with a reasonable (not
skinny) tyre, rear braking alone can be acceptable if body weight is
shifted back. *You cannot shift bodyweight as far back when holding
onto brake levers as is possible on a track bike. *On a road with
little camber, the rider only needs to hold the stem to effect
steering when braking, which means his weight can be further back. *So
'in fact' it appears your assumptions of braking performance are
clearly ill-founded.

You must live somewhere with different laws of physics than the rest
of us.
The limit on braking is defined by the angle between the front wheel
contact point and the CofG, because weight transfers onto the front
wheel when braking.

Again. Without brake levers the CofG can be taken further rearwards
so that more weight is taken by the rear wheel when braking. You dont
need to be in the hooks to brake if it wont do you any good..

On Nov 2, 2:27*pm, thirty-six wrote:
On 2 Nov, 18:17, Phil W Lee phil(at)lee-family(dot)me(dot)uk wrote:
thirty-six considered Mon, 2 Nov 2009 04:23:11
-0800 (PST) the perfect time to write:

On 2 Nov, 05:41, Phil W Lee phil(at)lee-family(dot)me(dot)uk wrote:
(Király) considered Sun, 01 Nov 2009 17:46:28 GMT
the perfect time to write:

wrote:
* *Fixies are a fad too. *There is no defensible reason why they can't
have hand brakes in addition to the back-pressure method of stopping. *

The fixie defenders will maintain that "I have the leg skills to stop
just as well as somebody with front and rear hand brakes".

I think half of their belief is a lack of understanding of the physics
of bicycle braking, and the other half is a machismo-inspired
unwillingness to understand it.

With no front brake, one needs twice the time and twice the distance to
stop, compared to somebody with a front brake. *If you are riding on a
paved surface and you have a front brake, you don't need your rear brake
*at all*.

It's worse than that - you can get far more braking from the front
wheel, so you lose much more than half the braking, and therefore need
much more than twice the stopping distance,
Somewhere between 3 and 4 times the distance, in fact.

On a wet road with a slick tyre. *On a dry road with a reasonable (not
skinny) tyre, rear braking alone can be acceptable if body weight is
shifted back. *You cannot shift bodyweight as far back when holding
onto brake levers as is possible on a track bike. *On a road with
little camber, the rider only needs to hold the stem to effect
steering when braking, which means his weight can be further back. *So
'in fact' it appears your assumptions of braking performance are
clearly ill-founded.

You must live somewhere with different laws of physics than the rest
of us.
The limit on braking is defined by the angle between the front wheel
contact point and the CofG, because weight transfers onto the front
wheel when braking.

Again. * Without brake levers the CofG can be taken further rearwards
so that more weight is taken by the rear wheel when braking. *You dont
need to be in the hooks to brake if it wont do you any good..

I ride fixed-gear bicycles year 'round and I have no idea
how to do what you are proposing. In any reasonable
gear for road riding (58in) you cannot lock up the rear
wheel without shifting your weight forward. Further, on
every road bicycle I have ridden, I can swing behind the
saddle with my ass nearly brushing the tire while braking.
I can't really do that on a fixed gear, at least easily.

On 2 Nov, 23:25, Norman wrote:
On Nov 2, 2:27*pm, thirty-six wrote:



On 2 Nov, 18:17, Phil W Lee phil(at)lee-family(dot)me(dot)uk wrote:
thirty-six considered Mon, 2 Nov 2009 04:23:11
-0800 (PST) the perfect time to write:

On 2 Nov, 05:41, Phil W Lee phil(at)lee-family(dot)me(dot)uk wrote:
(Király) considered Sun, 01 Nov 2009 17:46:28 GMT
the perfect time to write:

wrote:
* *Fixies are a fad too. *There is no defensible reason why they can't
have hand brakes in addition to the back-pressure method of stopping. *

The fixie defenders will maintain that "I have the leg skills to stop
just as well as somebody with front and rear hand brakes".

I think half of their belief is a lack of understanding of the physics
of bicycle braking, and the other half is a machismo-inspired
unwillingness to understand it.

With no front brake, one needs twice the time and twice the distance to
stop, compared to somebody with a front brake. *If you are riding on a
paved surface and you have a front brake, you don't need your rear brake
*at all*.

It's worse than that - you can get far more braking from the front
wheel, so you lose much more than half the braking, and therefore need
much more than twice the stopping distance,
Somewhere between 3 and 4 times the distance, in fact.

On a wet road with a slick tyre. *On a dry road with a reasonable (not
skinny) tyre, rear braking alone can be acceptable if body weight is
shifted back. *You cannot shift bodyweight as far back when holding
onto brake levers as is possible on a track bike. *On a road with
little camber, the rider only needs to hold the stem to effect
steering when braking, which means his weight can be further back. *So
'in fact' it appears your assumptions of braking performance are
clearly ill-founded.

You must live somewhere with different laws of physics than the rest
of us.
The limit on braking is defined by the angle between the front wheel
contact point and the CofG, because weight transfers onto the front
wheel when braking.

Again. * Without brake levers the CofG can be taken further rearwards
so that more weight is taken by the rear wheel when braking. *You dont
need to be in the hooks to brake if it wont do you any good..

I ride fixed-gear bicycles year 'round and I have no idea
how to do what you are proposing. *In any reasonable
gear for road riding (58in) you cannot lock up the rear
wheel without shifting your weight forward. *Further, on
every road bicycle I have ridden, I can swing behind the
saddle with my ass nearly brushing the tire while braking.
I can't really do that on a fixed gear, at least easily.

Move the handlebars close. Jump the rear wheel and hang behind the
saddle. You should lock the rear wheel easily.

On 3 Nov, 00:33, Phil W Lee phil(at)lee-family(dot)me(dot)uk wrote:
thirty-six considered Mon, 2 Nov 2009 11:27:16
-0800 (PST) the perfect time to write:



On 2 Nov, 18:17, Phil W Lee phil(at)lee-family(dot)me(dot)uk wrote:
thirty-six considered Mon, 2 Nov 2009 04:23:11
-0800 (PST) the perfect time to write:

On 2 Nov, 05:41, Phil W Lee phil(at)lee-family(dot)me(dot)uk wrote:
(Király) considered Sun, 01 Nov 2009 17:46:28 GMT
the perfect time to write:

wrote:
* *Fixies are a fad too. *There is no defensible reason why they can't
have hand brakes in addition to the back-pressure method of stopping. *

The fixie defenders will maintain that "I have the leg skills to stop
just as well as somebody with front and rear hand brakes".

I think half of their belief is a lack of understanding of the physics
of bicycle braking, and the other half is a machismo-inspired
unwillingness to understand it.

With no front brake, one needs twice the time and twice the distance to
stop, compared to somebody with a front brake. *If you are riding on a
paved surface and you have a front brake, you don't need your rear brake
*at all*.

It's worse than that - you can get far more braking from the front
wheel, so you lose much more than half the braking, and therefore need
much more than twice the stopping distance,
Somewhere between 3 and 4 times the distance, in fact.

On a wet road with a slick tyre. *On a dry road with a reasonable (not
skinny) tyre, rear braking alone can be acceptable if body weight is
shifted back. *You cannot shift bodyweight as far back when holding
onto brake levers as is possible on a track bike. *On a road with
little camber, the rider only needs to hold the stem to effect
steering when braking, which means his weight can be further back. *So
'in fact' it appears your assumptions of braking performance are
clearly ill-founded.

You must live somewhere with different laws of physics than the rest
of us.
The limit on braking is defined by the angle between the front wheel
contact point and the CofG, because weight transfers onto the front
wheel when braking.

Again. * Without brake levers the CofG can be taken further rearwards
so that more weight is taken by the rear wheel when braking. *You dont
need to be in the hooks to brake if it wont do you any good..

The rear-wheel braking limit will be limited by the deceleration which
produces enough unloading of the rear wheel that the tyre will no
longer grip. *The front wheel braking is limited only by the need to
stop the rear wheel actually rising.

There's one hell of a difference between just keeping the rear wheel
on the ground and keeping enough weight on it to provide any useful
grip for braking.

The best use for rear wheel braking in an emergency or maximum effort
stop is to judge when the rear wheel is about to lift, at which point
it will start sliding.

This thread is about track bikes (without specific mechaincal braking
devices).

Phil W Lee wrote:
[...]
You must live somewhere with different laws of physics than the rest
of us.
The limit on braking is defined by the angle between the front wheel
contact point and the CofG, because weight transfers onto the front
wheel when braking.

On a recumbent lowracer or tadpole trike with a low seat, it is possible
to lock the front wheel(s) on dry pavement.

--
Tom Sherman - 42.435731,-83.985007
I am a vehicular cyclist.