Cities Turning to Bicycles

[Alan Baker]

In article <[email protected]>,
Frank Krygowski <[email protected]> wrote:

> Alan Baker wrote:
>
> >
> > What prevents the driver from having driven the road before and
> > *knowing* there are no hills curves or blindspots?
>
> Ask Nate, Alan. Ask him how many minutes before he had gone down the
> road to check it for hills, curves, blind spots - and tree branches,
> pedestrians, drivers backing out of driveways, and other road hazards.

Ask him what? How many hills, curves and blind spots suddenly appeared
in the road?

As has already been pointed out, you can see much farther down the road
than your utterly ludicrous figure of 160 feet, drivers backing out of
driveways have reflectors and can be seen even further.


>
> Again: people who defend night driving at 75+ mph on rural two-lane
> roads lack the judgement to comment on mitigating neighborhood speeding.

People who condemn it without knowing the full circumstances just look
stupid.

--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard."

 

[Alan Baker]

In article <[email protected]>,
"Mark Jones" <[email protected]> wrote:

> "Frank Krygowski" <[email protected]> wrote in message
> news:[email protected]...
> > Again: people who defend night driving at 75+ mph on rural two-lane
> > roads lack the judgement to comment on mitigating neighborhood speeding.
> I can't think of any two lane roads near where I live that I would
> consider doing 75+ mph at night. Too risky when you consider
> that it isn't just other motorists that you need to be concerned
> with. Wild animals tend to roam about at night and may wander
> out onto the roadway. Hitting a deer would ruin your night.

Great.

But where you live wasn't the issue.

--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard."

 

[Alan Baker]

In article <[email protected]>,
Frank Krygowski <[email protected]> wrote:

> Nate Nagel wrote:
>
> > Frank Krygowski wrote:
> >
> >> Nate Nagel wrote:
> >>
> >>>
> >>> Blind curves should *never* be decreasing radius. Never. If a road
> >>> has traffic in two directions, a blind curve should be, by necessity,
> >>> constant radius.
> >>
> >>
> >>
> >> I thought you had driven in West Virginia. And Western
> >> Pennsylvania.
> >>
> >> So every road that has to curve around an Appalachian hill should have
> >> the hillside sculpted into a perfect circular arc?
> >>
> >
> > There's a huge difference between a western PA goat track and an
> > Interstate highway. A road cut into a hillside you expect to be
> > surprised, and allow a little extra cushion in your speed.
>
> Seems to me you should _always_ allow a reasonable cushion in your
> speed. If you ever find yourself driving at ten tenths on a public
> road, you've made a mistake.
>
> Now, mistakes happen. But it's a bit immature to admit your mistake,
> describe it in great detail, then try to pass it off as impossible to
> avoid. And that's pretty ineffective, too, when others can point out
> that they did _not_ make that mistake.
>
> And if you meant the mistake was merely difficult (not impossible) to
> avoid - then those who have avoided it have demonstrated greater
> competence than you did, haven't they?

The huge mistake is for advisory limits to be set so inconsistently that
one doesn't have an honest idea for what speeds can be used in such
situations.

--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard."

 

[Alan Baker]

In article <[email protected]>,
[email protected] (Nate Nagel) wrote:

> Arif Khokar <[email protected]> wrote in message
> news:<[email protected]>...
> > Alan Baker wrote:
> >
> > > I've driven my brother's Nissan Pathfinder (even before it had its
> > > shocks replaced) and it can easily -- easily -- more than double the
> > > advisory speeds on most ramps.
> >
> > Advisory speeds are based on the comfort level of a driver driving a
> > 1939 Ford Vehicle. The lateral force would be enough to have a "ball on
> > a string" deviate 10 degrees from the vertical position. Most drivers
> > take curves such that the deviation would be between 12 and 14 degrees,
> > IIRC.
>
> found this site:
>
> http://manuals.dot.state.tx.us/dynaweb/coltraff/szn/@Generic__BookTextView/400
> 9;cs=default;ts=default
>
> I don't see any mention of a 1939 Ford, but essentially that appears
> to be correct. They do apparently allow higher G-forces for very slow
> speed turns, but 10 degrees is the recommended value for 35 MPH or
> higher. In any case the maximum value allowed is 14 degrees, still
> far less than people seem to find acceptable in day to day driving. I
> wouldn't be surprised if a 10 degree ball bank indicator reading *was*
> perfectly safe and comfortable in a bone stock '39 Ford, honestly.
> Perhaps it's time to revisit these standards; how often is a vehicle
> in regular use anywhere in the US older than the mid-late 1960's?
>
> Key quote: "The speed to be posted on the curve should not be reduced
> arbitrarily below that determined by the procedures provided in this
> section." Hmm, looks like *that* recommendation isn't followed across
> the board...
>
> Note that there really isn't *any* hard standard for advisory speeds
> for exit ramps, although obviously I have no way of knowing if that
> section of this document is derived from the Green Book or is unique
> to the state of TX.
>
> nate

It also shows how stupid the system is.

A ball bank indicator? One big problem with it: in addition to the
movement of the ball due to lateral g forces, you also get movement due
to the roll of the vehicle. And since different vehicles roll different
amounts, you automatically get inconsistent results.

--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard."

 

[Wayne Pein]

Alan Baker wrote:

> In article <HoI8d.19620$n%[email protected]>,
> Wayne Pein <[email protected]> wrote:
>
>
>>>I really find it hard to understand how he could justify a decreasing
>>>radius turn as being a reasonable thing to build. Just because a
>>>roading program can spit out the stakeout points for a particular
>>>piece of roadway, that doesn't mean that it is a good idea to build it.
>>>
>>>
>>
>>Such a turn could be designed explicitly for the purpose of slowing
>>traffic. In that case, a sign can warn of it.
>>
>>Wayne
>
>

An off-ramp from a freeway that has a stop light at the end of the ramp.
One must slow or stop anyway, and the forced slowing with a decreasing
radius geometric additionally sends the message that the road about to
be entered is not a freeway.

Wayne

 

[Alan Baker]

In article <pHX8d.19737$n%[email protected]>,
Wayne Pein <[email protected]> wrote:

> Alan Baker wrote:
>
> > In article <HoI8d.19620$n%[email protected]>,
> > Wayne Pein <[email protected]> wrote:
> >
> >
> >>>I really find it hard to understand how he could justify a decreasing
> >>>radius turn as being a reasonable thing to build. Just because a
> >>>roading program can spit out the stakeout points for a particular
> >>>piece of roadway, that doesn't mean that it is a good idea to build it.
> >>>
> >>>
> >>
> >>Such a turn could be designed explicitly for the purpose of slowing
> >>traffic. In that case, a sign can warn of it.
> >>
> >>Wayne
> >
> >
>
> An off-ramp from a freeway that has a stop light at the end of the ramp.
> One must slow or stop anyway, and the forced slowing with a decreasing
> radius geometric additionally sends the message that the road about to
> be entered is not a freeway.
>
> Wayne

Why not have a constant radius turn of the same radius as your proposed
decreasing radius ramp at its tightest? What would be the disadvantage?

--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard."

 

[Frank Krygowski]

[Irrelevant newsgroups removed from distribution list. Poster notified
as a courtesy.]


Brent P wrote:
> In article <[email protected]>, Frank Krygowski wrote:
>
>[regarding braking a bicycle while in a turn:]
>
>>IOW, you can
>>certainly brake to a reaonable degree in a turn. Pretending this is
>>impossible shows you are either _amazingly_ inexperienced, or amazingly
>>closed-minded.
>
>
> It doesn't make it good practice on public roads. Which is what I thought
> we were discussing. Weren't you just objecting to such approaches to
> taking a turn or curve? Stating that the driver should be able to judge
> it ahead of time and already be going an appropiate speed?

There cannot possibly be more than one person reading this who doesn't
brake while turning!

And frankly, I doubt there is even one person. IOW, I can't believe
that _you_ actually stay completely off the brakes any time you're in a
turn!

One should certainly judge the turn ahead of time, as well as possible,
and choose an appropriate speed. But this is what every rider (and
driver) does on every street corner.

If one is to take a turn smoothly, one will gradually blend from a
straight path to one that curves slighly, then more sharply, until the
desired turn radius is achieved. And one will gradually slow to the
appropriate speed while doing this.

>>Or, if you prefer, from the r.b.FAQ (in an article by Jobst Brandt):
>>"Braking in Corners
>
>
>>Why brake in the turn? If all braking is done before the turn, speed
>>will be slower than necessary before the apex. Anticipating maximum
>>speed for the apex is difficult, and because the path is not a
>>circular arc, speed must be trimmed all the way to that point. Fear
>>of braking in curves usually comes from an incident of injudicious
>>braking at a point where braking should have been done with a gentle
>>touch to match the conditions.
> ...
>
>
> Yes, in racing braking into the apex is just fine. You're supposed to go
> to the edge like that. I've done it when racing people myself. I've done
> it on curves when nobody else was around. I've done it when I've
> misjudged a curve. A gentle touch geting right to the edge in a curve.
> But we were discussing public roads not racing.
>
> Interesting how you bring up bike racing to defend your posistion.

I was discussing normal riding, not racing.

--
Frank Krygowski [To reply, remove rodent and vegetable dot com.
Substitute cc dot ysu dot
edu]

 

[Nate Nagel]

Tim McNamara <[email protected]> wrote in message news:<[email protected]>...
> Nate Nagel <[email protected]> writes:
>
> > Tim McNamara wrote:
> >
> >> [email protected] (Brent P) writes:
> >>
> >>>In article <[email protected]>, Tim McNamara wrote:
> >>>
> >>>
> >>>>Indeed, my review of some of the traffic management literature
> >>>>(e.g.,
> >>>>http://ops.fhwa.dot.gov/Travel/traffic/freeway_management_handbook/chapter5.htm)
> >>>>suggests that traffic flow obeys the mathematics governing
> >>>>hydraulic flow, and that there is a maximum throughput in any
> >>>>hydraulic system before turbulence is created. Turbulence in turn
> >>>>creates drag and slows throughput dramatically. You can set the
> >>>>speed limit at the 85th percentile, but that will not "smooth out"
> >>>>traffic flow when there are just too many cars on the road at the
> >>>>same time- which is about 8 hours of every day in major urban
> >>>>areas.
> >>>
> >>>A smooth flow can sustain a higher throughput delaying the onset of
> >>>traffic jams and lessening how long they last.
> >> In an ideal world, sure. But you're dealing with a situation where
> >> by definition 85% of drivers are driving below the posted limit-
> >> which means the faster drivers are tailgating, trying to pass, and
> >> creating turbulence in the traffic flow. This rapidly becomes
> >> congestion. You're also dealing with drivers of radically
> >> different driving skills and driving preferences, so you get people
> >> driving 45 mph in the center lane on a road posted at 80 mph (in
> >> your ideal scenario of using the 85th percentile).
> >
> > Whoa! Hod it right there! That person should get a ticket - no
> > matter what the speed limit is. That's a completely separate issue,
> > and another pet peeve of mine.
>
> Well, then you're having to control people's behavior further by
> forcing the minimum speed limit higher than the current 45 mph posted
> on most interstate highways. Brent already complained vociferously
> about people telling him how to drive, but here we go again- this time
> on the slower rather than faster drivers.

Not necessarily. I don't have a problem with people driving 45 MPH on
the freeway, but I have a problem with them doing it in lanes other
than the right while everyone else is going a minimum of 70.

>
> > Slow traffic stays to the right, faster traffic passes to the left,
> > that way nobody gets "held up" until the highway is completely full.
> > that's the way it's *supposed* to work, anyway.
>
> Well, that's what *I* was taught in driver's ed lo those many many
> years ago. I see a *lot* of people, though driving 50 and slower in
> the middle lane.

As do I. But that doesn't change the fact that it's illegal in all
but a few states, so we don't even need to legislate anything. The
law just simply needs to be enforced... (not sure where you're
reading this from, but in RAD there is another thread going about the
utter and complete lack of enforcement of a supposedly new, stronger
KRETP law.)

> My mother- an alert and oriented 75 year old- claims
> she was taught that slow traffic should drive slow in the middle lane
> so that people can pass on either side. I've not had a lot of success
> convincing her this is a Bad Idea. Fortunately for all concerned she
> almost never drives on the highways.

Indeed, and I concur with your assessment.

>
> > The idea is to make it more like a laminar flow than a completely
> > turbulent one.
>
> If we can.

Sure we can. Other civilized countries seem to manage it fairly well,
and I have even experienced rare, blissful moments in this country
where I've found myself on a highway where everyone was KRETP. Just
for the record, I do tend to drive faster than the median speed of
traffic, but I'm rarely the *fastest* driver on the road, and yes, I
do do my part by yielding to faster traffic. Even when I'm not the
fastest driver on the road I still find things much less stressful
when I'm more able to accurately predict how those around me will
behave.

nate

 

[Nate Nagel]

Wayne Pein wrote:

> Alan Baker wrote:
>
>> In article <HoI8d.19620$n%[email protected]>,
>> Wayne Pein <[email protected]> wrote:
>>
>>
>>>> I really find it hard to understand how he could justify a decreasing
>>>> radius turn as being a reasonable thing to build. Just because a
>>>> roading program can spit out the stakeout points for a particular
>>>> piece of roadway, that doesn't mean that it is a good idea to build it.
>>>>
>>>>
>>>
>>> Such a turn could be designed explicitly for the purpose of slowing
>>> traffic. In that case, a sign can warn of it.
>>>
>>> Wayne
>>
>>
>>
>
> An off-ramp from a freeway that has a stop light at the end of the ramp.
> One must slow or stop anyway, and the forced slowing with a decreasing
> radius geometric additionally sends the message that the road about to
> be entered is not a freeway.
>
> Wayne
>

Why would you want to do that? I would think that would lead motorists
to misjudge the exit to be safe at a faster speed than if it were a
constant radius the whole way through. I would think the correct ramp
shape would be a constant radius curve, with an "stop ahead" sign over
the advisory speed sign to alert motorists to the signal.

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

 

[Nate Nagel]

Frank Krygowski wrote:

> Brent P wrote:
>
>> In article <[email protected]>, Frank Krygowski wrote:
>>
>>> Brent P wrote:
>>>
>>>
>>>> I would suggest Frank ride his bicycle through a decreasing radius
>>>> turn that wasn't visable until he was in it such that it forced him
>>>> to brake hard. This would probably be the best lesson as to why this
>>>> sort of design should be avoided. Braking while turning is as
>>>> ill-advised on a bicycle as it is driving. Probably more so.
>>>
>>>
>>>
>>>
>>> Almost every time I make a turn on the bike, it's done with a
>>> decreasing radius, and with braking while in the turn! This is
>>> normal for a bicycle!
>>
>>
>>
>>> Sheesh. Newbies!
>>
>>
>>
>> Not braking by coasting frank. braking with the brakes. Coasting is
>> normal on the road, not squeezing the hand brakes.
>
>
> Yes, braking with the brakes, Brent. While in a curve. Every day. It's
> quite normal.
>
>

google for "friction circle" to see why that's a bad idea (yes, on a
bike too.)

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

 

[Nate Nagel]

Alan Baker wrote:

> In article <[email protected]>,
> [email protected] (Nate Nagel) wrote:
>
>
>>Arif Khokar <[email protected]> wrote in message
>>news:<[email protected]>...
>>
>>>Alan Baker wrote:
>>>
>>>
>>>>I've driven my brother's Nissan Pathfinder (even before it had its
>>>>shocks replaced) and it can easily -- easily -- more than double the
>>>>advisory speeds on most ramps.
>>>
>>>Advisory speeds are based on the comfort level of a driver driving a
>>>1939 Ford Vehicle. The lateral force would be enough to have a "ball on
>>>a string" deviate 10 degrees from the vertical position. Most drivers
>>>take curves such that the deviation would be between 12 and 14 degrees,
>>>IIRC.
>>
>>found this site:
>>
>>http://manuals.dot.state.tx.us/dynaweb/coltraff/szn/@Generic__BookTextView/400
>>9;cs=default;ts=default
>>
>>I don't see any mention of a 1939 Ford, but essentially that appears
>>to be correct. They do apparently allow higher G-forces for very slow
>>speed turns, but 10 degrees is the recommended value for 35 MPH or
>>higher. In any case the maximum value allowed is 14 degrees, still
>>far less than people seem to find acceptable in day to day driving. I
>>wouldn't be surprised if a 10 degree ball bank indicator reading *was*
>>perfectly safe and comfortable in a bone stock '39 Ford, honestly.
>>Perhaps it's time to revisit these standards; how often is a vehicle
>>in regular use anywhere in the US older than the mid-late 1960's?
>>
>>Key quote: "The speed to be posted on the curve should not be reduced
>>arbitrarily below that determined by the procedures provided in this
>>section." Hmm, looks like *that* recommendation isn't followed across
>>the board...
>>
>>Note that there really isn't *any* hard standard for advisory speeds
>>for exit ramps, although obviously I have no way of knowing if that
>>section of this document is derived from the Green Book or is unique
>>to the state of TX.
>>
>>nate
>
>
> It also shows how stupid the system is.
>
> A ball bank indicator? One big problem with it: in addition to the
> movement of the ball due to lateral g forces, you also get movement due
> to the roll of the vehicle. And since different vehicles roll different
> amounts, you automatically get inconsistent results.
>

Maybe *YOUR* car has perceptible roll at under 0.5G <G>

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

 

[Wayne Pein]

Alan Baker wrote:

>>An off-ramp from a freeway that has a stop light at the end of the ramp.
>>One must slow or stop anyway, and the forced slowing with a decreasing
>>radius geometric additionally sends the message that the road about to
>>be entered is not a freeway.
>>
>>Wayne
>
>
> Why not have a constant radius turn of the same radius as your proposed
> decreasing radius ramp at its tightest? What would be the disadvantage?
>

Starting with a larger radius is more consistent with the high speed
entering the off ramp. As speed is lost, the turn can be tighter to
ensure just that.

Wayne

 

[Alan Baker]

In article <[email protected]>,
Nate Nagel <[email protected]> wrote:

> Alan Baker wrote:
>
> > In article <[email protected]>,
> > [email protected] (Nate Nagel) wrote:
> >
> >
> >>Arif Khokar <[email protected]> wrote in message
> >>news:<[email protected]>...
> >>
> >>>Alan Baker wrote:
> >>>
> >>>
> >>>>I've driven my brother's Nissan Pathfinder (even before it had its
> >>>>shocks replaced) and it can easily -- easily -- more than double the
> >>>>advisory speeds on most ramps.
> >>>
> >>>Advisory speeds are based on the comfort level of a driver driving a
> >>>1939 Ford Vehicle. The lateral force would be enough to have a "ball on
> >>>a string" deviate 10 degrees from the vertical position. Most drivers
> >>>take curves such that the deviation would be between 12 and 14 degrees,
> >>>IIRC.
> >>
> >>found this site:
> >>
> >>http://manuals.dot.state.tx.us/dynaweb/coltraff/szn/@Generic__BookTextView/4
> >>00
> >>9;cs=default;ts=default
> >>
> >>I don't see any mention of a 1939 Ford, but essentially that appears
> >>to be correct. They do apparently allow higher G-forces for very slow
> >>speed turns, but 10 degrees is the recommended value for 35 MPH or
> >>higher. In any case the maximum value allowed is 14 degrees, still
> >>far less than people seem to find acceptable in day to day driving. I
> >>wouldn't be surprised if a 10 degree ball bank indicator reading *was*
> >>perfectly safe and comfortable in a bone stock '39 Ford, honestly.
> >>Perhaps it's time to revisit these standards; how often is a vehicle
> >>in regular use anywhere in the US older than the mid-late 1960's?
> >>
> >>Key quote: "The speed to be posted on the curve should not be reduced
> >>arbitrarily below that determined by the procedures provided in this
> >>section." Hmm, looks like *that* recommendation isn't followed across
> >>the board...
> >>
> >>Note that there really isn't *any* hard standard for advisory speeds
> >>for exit ramps, although obviously I have no way of knowing if that
> >>section of this document is derived from the Green Book or is unique
> >>to the state of TX.
> >>
> >>nate
> >
> >
> > It also shows how stupid the system is.
> >
> > A ball bank indicator? One big problem with it: in addition to the
> > movement of the ball due to lateral g forces, you also get movement due
> > to the roll of the vehicle. And since different vehicles roll different
> > amounts, you automatically get inconsistent results.
> >
>
> Maybe *YOUR* car has perceptible roll at under 0.5G <G>
>
> nate

*Every* car does.

--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard."

 

[Alan Baker]

In article <Dn19d.19776$n%[email protected]>,
Wayne Pein <[email protected]> wrote:

> Alan Baker wrote:
>
> >>An off-ramp from a freeway that has a stop light at the end of the ramp.
> >>One must slow or stop anyway, and the forced slowing with a decreasing
> >>radius geometric additionally sends the message that the road about to
> >>be entered is not a freeway.
> >>
> >>Wayne
> >
> >
> > Why not have a constant radius turn of the same radius as your proposed
> > decreasing radius ramp at its tightest? What would be the disadvantage?
> >
>
> Starting with a larger radius is more consistent with the high speed
> entering the off ramp. As speed is lost, the turn can be tighter to
> ensure just that.
>
> Wayne

But you create a situation where driver's can't *see* (in many cases,
anyway) the radius where it tightens.

--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard."

 

[Peter]

Nate Nagel wrote:
> Frank Krygowski wrote:
>
>> Brent P wrote:
>>
>>> In article <[email protected]>, Frank Krygowski wrote:
>>>
>>>> Brent P wrote:
>>>>
>>>>
>>>>> I would suggest Frank ride his bicycle through a decreasing radius
>>>>> turn that wasn't visable until he was in it such that it forced him
>>>>> to brake hard. This would probably be the best lesson as to why
>>>>> this sort of design should be avoided. Braking while turning is as
>>>>> ill-advised on a bicycle as it is driving. Probably more so.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Almost every time I make a turn on the bike, it's done with a
>>>> decreasing radius, and with braking while in the turn! This is
>>>> normal for a bicycle!
>>>
>>>
>>>
>>>
>>>> Sheesh. Newbies!
>>>
>>>
>>>
>>>
>>> Not braking by coasting frank. braking with the brakes. Coasting is
>>> normal on the road, not squeezing the hand brakes.
>>
>>
>>
>> Yes, braking with the brakes, Brent. While in a curve. Every day.
>> It's quite normal.
>>
>>
>
> google for "friction circle" to see why that's a bad idea (yes, on a
> bike too.)

It's only a bad idea if you enter the turn at a speed where *all* of
the available traction is used for cornering, i.e. too fast. But since
many turns are entered before the driver can completely see the
turning radius throughout the turn he should always leave sufficient
margin so there is still traction available for braking in addition to
cornering. Fortunately the mathematics of perpendicular vector addition
help us out here. The equation of a circle is x^2 + y^2 = r^2 where we
can use 'x' for the traction available for braking and 'y' for the
traction available for cornering, and 'r', the resultant is the total
available traction. Let's assume the total traction is 1. Then
entering the turn so fast that cornering alone requires a traction of
1.0 would leave nothing available for braking. But entering even a
little slower, say where cornering only requires a traction of 0.9 now
allows us to use some braking up to a traction of sqrt(1-.9^2) = 0.44

Because the forces are perpendicular we can use our brakes up to almost
44% of maximum and simultaneously corner at 90% of maximum without
exceeding 100% of the available traction. Even if the driver (or
cyclist) cuts it closer and is cornering so fast that he's using
95% of the available traction he can still apply the brakes at 31% of
maximum before risking a skid. And even the real thrill-seeker
who corners at 99% still has 14% of maximum braking available to him
before initiating a skid. So yes, the brakes should be applied
carefully and with some caution while cornering, but there is nothing
about "friction circles" (really just basic vector force addition)
that says no braking should be combined with cornering.

I live near a 3500' hill which I frequently ascend and descend on my
bicycle, usually in the company of other cyclists. The road is very
winding and, as is common of many mountain roads, has turns where the
radius of curvature varies. I use my brakes on the way down in
most of the turns and don't think I've ever seen anyone descend this
hill without doing a substantial amount of braking while in the turns.

 

[Frank Krygowski]

Nate Nagel wrote:
> Frank Krygowski wrote:
>
>>
>> Yes, braking with the brakes, Brent. While in a curve. Every day.
>> It's quite normal.
>>
> google for "friction circle" to see why that's a bad idea (yes, on a
> bike too.)

I don't need to google friction circles. I know all about them.

It's interesting that Brent claimed _I_ was talking about racing, i.e.
limit of adhesion situations, now that you are using a term that really
pertains only to that situation.

If a vehicle is not undergoing extreme lateral acceleration, there is
plenty of friction available for braking as well as turning. And, as on
freeway exit ramps, I have sense to stay away from ten-tenths cornering
moves.

--
--------------------+
Frank Krygowski [To reply, remove rodent and vegetable dot com,
replace with cc.ysu dot edu]

 

[RogerDodger]

I'm sure that in your mind, the Studebaker was _much_ better at panic
stops than a typical car, right? ;-) And I'm sure that you precisely
tweaked the headlight voltage and aiming to get a few more feet out of
those headlight beams, right? ;-) And of course, we _know_ that, like
almost all Americans, you're better than average drivers, right? ;-)

But despite all the "Boy, am I good" self-delusion that you treasure,
it's _still_ true that rural two-lane roads feature curves, hills,
interesections and blind spots. They can have all sorts of obstructions
or potential victims in the road. And the driving you describe, defend
and brag about was illegal, irresponsible and stupid.

What's amazing is that you do this in a thread where you're arguing that
your judgement is better than that of highway officials and neighborhood
residents. You argue that you should be able to choose your own speed
through neighborhoods, and as evidence, you brag about your
irresponsible driving.

Not only are you losing the argument on a factual basis, you're shooting
yourself in the foot with your own bragging.


Frank Krygowski [To reply, remove rodent and vegetable dot com.
Substitute cc dot ysu dot
edu]

Well said Frank

 

[Brent P]

In article <[email protected]>, Frank Krygowski wrote:
> Nate Nagel wrote:
>> Frank Krygowski wrote:
>>
>>>
>>> Yes, braking with the brakes, Brent. While in a curve. Every day.
>>> It's quite normal.
>>>
>> google for "friction circle" to see why that's a bad idea (yes, on a
>> bike too.)
>
> I don't need to google friction circles. I know all about them.
>
> It's interesting that Brent claimed _I_ was talking about racing, i.e.
> limit of adhesion situations, now that you are using a term that really
> pertains only to that situation.

It was your quote about what a 'skilled bike racer' does. You are
basically telling us we are wrong to apply racing techniques to
driving on the public roads while at the same time chastising us for
not doing so and prefering not to have to.

 

[Brent P]

In article <[email protected]>, Frank Krygowski wrote:
> [Irrelevant newsgroups removed from distribution list. Poster notified
> as a courtesy.]

Courtesy. ********. You cut off r.a.d and emailed me this so I'd would
wade throught the 1000+ post thread in another newsgroup to reply. Since
driving is still part of the topic you can't hide behind it being topical.
It's lowest of usenet tricks.

> Brent P wrote:
>> In article <[email protected]>, Frank Krygowski wrote:

>>>IOW, you can
>>>certainly brake to a reaonable degree in a turn. Pretending this is
>>>impossible shows you are either _amazingly_ inexperienced, or amazingly
>>>closed-minded.

>> It doesn't make it good practice on public roads. Which is what I thought
>> we were discussing. Weren't you just objecting to such approaches to
>> taking a turn or curve? Stating that the driver should be able to judge
>> it ahead of time and already be going an appropiate speed?

> There cannot possibly be more than one person reading this who doesn't
> brake while turning!

> And frankly, I doubt there is even one person. IOW, I can't believe
> that _you_ actually stay completely off the brakes any time you're in a
> turn!

Most turns I am off the brakes before the apex, sometimes before the
turn depending on how sharp it is. I don't want to get into a posistion
where I have to brake harder and turn sharper than I have the traction
for. I have a scar on my right knee from making such a mistake as a
child as I made a late decision to turn at the bottom of a fast downhill.
It's not worth the risk to go through the turn a couple mph faster.

I ride streets. Most turns are from a road that is 90 degrees to
the road I am going on to. There is a low return on pushing the bicycle
to it's traction limits. Sure I'd save a little momentum that way, but
it's not like the 1/10 of second I'll save getting from a to b or when I
am riding just for fun is going to make a difference. It's not a race
and because I am in traffic I can't take the best line through a curve
or a turn anyway. The time savings aren't worth the risk of a fall.

> One should certainly judge the turn ahead of time, as well as possible,
> and choose an appropriate speed. But this is what every rider (and
> driver) does on every street corner.

If we were racing, the goal is to take the straightest line and brake the
least. Braking when too far into the turn can cause a loss of traction
and the problems associated with that. Finding out you need to brake too
hard to make the turn when you are too far into it is also a problem.
Braking too much early simply means going through the turn slower. Which
do you think is better for street driving/riding?

You've already chastised Nate for ending up in a curve going faster than
what the speed of the apex is. If you are going to insist that we should
be braking to the apex on the street that is inconsistant with your
chastisement of nate's driving. If we are always going to be looking for
the maximum apex speed, occasionally we are going to be going too fast
and get into trouble and need to deal with it. That's the nature of such
flirting with the limits, and why there is a difference between racing
and driving on the public roads.

So which is it Frank? Do we all try to find the maximum possible speed of
every curve and turn on the road by delaying our braking until we can see
what the apex is, knowing full well that sometimes it will require harder
braking than we have traction for _OR_ make a reasonable estimation of
what speed we need to be at with some cushion as we go into the turn so
we don't get into trouble with only the sacrifice of a slight amount of
speed? And if the later, wouldn't consistant signage be helpful in that
goal?

Not to mention that roads have things like lanes and shoulders that
prevent us from taking the best lines through the curve legally much of
the time anyway. So it's not like taking the curve at the maximum
possible speed is doable anyway.

If I said that since I upgraded the brakes on my car that I wait longer
into the the turn to brake so that I can maximize my speed through the
apex and accelerate out, you'd call me a reckless driver. But that's
very much what you've chastised me for _NOT_ recommending.

>> Interesting how you bring up bike racing to defend your posistion.

> I was discussing normal riding, not racing.

Your quote brings up racing.

 

[Nate Nagel]

Frank Krygowski wrote:

> Nate Nagel wrote:
>
>> Frank Krygowski wrote:
>>
>>>
>>> Yes, braking with the brakes, Brent. While in a curve. Every day.
>>> It's quite normal.
>>>
>> google for "friction circle" to see why that's a bad idea (yes, on a
>> bike too.)
>
>
> I don't need to google friction circles. I know all about them.
>
> It's interesting that Brent claimed _I_ was talking about racing, i.e.
> limit of adhesion situations, now that you are using a term that really
> pertains only to that situation.
>
> If a vehicle is not undergoing extreme lateral acceleration, there is
> plenty of friction available for braking as well as turning. And, as on
> freeway exit ramps, I have sense to stay away from ten-tenths cornering
> moves.
>

But that's exactly what you were busting me on earlier - entering a
corner at, say, 6/10 and suddenly discovering that I needed 10/10 or
more - which can happen. You also suggested that I slow down in that
situation, implying braking...

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel