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Cities Turning to Bicycles - Page 73

post #1081 of 1138

Re: Cities Turning to Bicycles

In article <4163f534$1@news.ysu.edu>, Frank Krygowski wrote:
> Brent P wrote:
>
>> In article <416364f8$1@news.ysu.edu>, 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.


Not surprising given your other foolishness. It also shows that you
likely putter along at sidewalk speeds. At the road speeds I ride
braking in a turn on a bicycle begins to overtax the avialable traction.

A bicycle like any other vehicle has a finite amount of traction. It can
be used for braking, accelerating, or turning and any combination there
of. This is why it is proper form to brake before entering the turn. I
brake to the speed I can take the turn at, remain at that speed or coast
into the turn and accelerate out.
post #1082 of 1138

Re: Cities Turning to Bicycles

In article <m24ql7apmv.fsf@Stella-Blue.local>, Tim McNamara wrote:

> 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.


Another creative spin job.

I haven't seen anyone drive 45mph on an interstate in free flowing
traffic since the last time I did it following a construction zone speed
limit. And I was the only one obeying it at great risk to myself for
being so far under the flow speed.

But anyway... KRETP takes care of people who want to drive slower. If
they are off to the right and people passing them return to the right
lanes after the pass is complete there isn't an issue. This is why a 911
and a duex cheveux can share the same autobahn.
post #1083 of 1138

Re: Cities Turning to Bicycles

In article <m2zn2z9axg.fsf@Stella-Blue.local>, Tim McNamara wrote:
> tetraethylleadREMOVETHIS@yahoo.com (Brent P) writes:
>
>> In article <m2acv08sxj.fsf@Stella-Blue.local>, Tim McNamara wrote:
>>> tetraethylleadREMOVETHIS@yahoo.com (Brent P) writes:

>>
>>>> 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.

>>
>> Less rapidly with 85th% limits and KRETP, than the current LLBing
>> situation with under posted limits.

>
> Uhh... KREPT? LLB?


Keep Right Except To Pass. Left Lane Block(er)

>>> Seems to me you are only looking at the up side which fulfills your
>>> desire to drive faster than you legally can now.

>>
>> 85th percentile limits won't allow me to drive any faster than I do
>> now. Legally isn't even a consideration because enforcement of the
>> underposted limits is effectively zero for the speeds I drive.
>>
>> I am selfish in that I want better flow. I grow tired backups caused
>> by one LLB who refuses to yield the passing lane to the 15 people
>> behind him.
>>
>>> There are serious problems to raising speed limits and with the
>>> 85th percentile proposal.

>>
>> A loss of revenue being the only one.


> You are contradicting yourself. If enforcement of the speed limit is
> effectively zero, there is no significant revenue being generated and
> therefore there could be no significant loss of revenue. You are also
> showing a severe lack of willingness to look at the issue objectively
> if you think a "loss of revenue" is the only problem posed by higher
> speed limits.


Effectively zero for the speeds I drive when and where I drive. I
apologize for the error, the additional text I edited out by mistake. Yes,
there would be little of revenue going through the city of chicago since
it is so lightly patrolled that it is effectively zero. However, there
would be a huge loss of revenue on I294 on weekends.

But even effectively zero enforcement is still can bring in about alot
revenue for the government when there are enough people. The odds of any
one motorist being stopped is low. But even .1% of a huge number is still
significant money. But for any one driver it's effectively zero.
post #1084 of 1138

Re: Cities Turning to Bicycles

In article <m2vfdn9av7.fsf@Stella-Blue.local>, Tim McNamara wrote:
> tetraethylleadREMOVETHIS@yahoo.com (Brent P) writes:
>
>> In article <m2655o8son.fsf@Stella-Blue.local>, Tim McNamara wrote:
>>
>>> But will it narrow the distribution of speeds? Will the people who
>>> drive no faster than 50 or 55 mph now suddenly decide they'll
>>> happily drive at 75 or 80 just because the speed limit got raised?

>>
>> If you are driving 50 or 55mph on a chicago interstate it's because
>> you can't get another ticket, you believe in slavish obedence to the
>> law,you are carrying drugs, you are carrying explosives, your
>> vehicle shouldn't be on the road at all, you are in no condition to
>> be driving, or you are doing some sort of traffic experiment.
>>
>> Because I see even old women drive their age on local
>> interstates. And they aren't younger than 70.

>
> Your opinions have obscured your perception of reality, Brent.


I've driven the posted interstate speed limit as an experiment to see
things from that perspective. Besides nearly being rearended a few times,
spending 90% of the time watching my mirrors, I noticed I was aggrivating
even elderly drivers. One particular instance was two old women in a
buick who passed me with at least a 15mph differentional. They were the
only old people to pass me, simply the most amusing and memerable by
appearance and what they were driving. They were the classic slow, in the
way, traffic clogging old people in appearance and they were going
significantly faster than the posted limit.
post #1085 of 1138

Re: Cities Turning to Bicycles

Arif Khokar <akhokar1234@wvu.edu> wrote in message news:<Z9P8d.6174$sx2.321@news01.roc.ny>...
> 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/dynaw...ult;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
post #1086 of 1138

Re: Cities Turning to Bicycles

Brent P wrote:

> In article <4163f534$1@news.ysu.edu>, Frank Krygowski wrote:
>
>>Yes, braking with the brakes, Brent. While in a curve. Every day.
>>It's quite normal.

>
>
> Not surprising given your other foolishness. It also shows that you
> likely putter along at sidewalk speeds. At the road speeds I ride ....


Wait a minute! Are you _purposely_ imitating Fabrizio? ;-)


> ... braking in a turn on a bicycle begins to overtax the avialable traction.


Looks like physics education isn't what it used to be.

It's not the speed that matters; it's the acceleration. If the total of
your longitudinal plus radial accelerations are within reasonable
limits, you'll have no problems braking in a curve. 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.

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.

Substantial weight transfer from the rear to the front wheel will
occur with strong use of the front brake on good traction just before
entering the curve. When traction is poor or the lean angle is great,
deceleration cannot be large and therefore, weight transfer will be
small, so light braking with both wheels is appropriate. If traction
is miserable, only the rear brake should be used, because although a
rear skid is recoverable, a front skid is generally not. An exception
to this is in deep snow, where the front wheel can slide and function
as a sled runner while being steered.

Braking at maximum lean

For braking in a curve, take the example of a rider cornering with
good traction, leaning at 45 degrees, the equivalent of 1G centrifugal
acceleration. Braking with 1/10g increases the traction demand by one
half percent. The sum of cornering and braking vectors is the square
root of the sum of their squares, SQRT(1^2+0.1^2)=1.005 or an increase
of 0.005. In other words, there is room to brake substantially during
maximum cornering. Because the lean angle changes as the square of
the speed, braking can rapidly reduce the angle and allow even more
braking. For this reason skilled racers nearly always apply both
brakes into the apex of turns."



Regarding puttering along at sidewalk speeds: Well, we can't really
prove anything without you and I riding side by side, but no, I'm not
considered slow. In fact, without knowing anything about your riding
speed, I wouldn't have any fear of keeping up with you. That comment of
yours was mistaken and foolish.

Yet again.


--
Frank Krygowski [To reply, remove rodent and vegetable dot com.
Substitute cc dot ysu dot
edu]
post #1087 of 1138

Re: Cities Turning to Bicycles

Matthew Russotto wrote:

> In article <41632ca2$1@news.ysu.edu>,
> Frank Krygowski <frkrygow@mousepotato.com> wrote:
>
>>Matthew Russotto wrote:
>>
>>>obstructions you mention are bad for bicyclists, horse-drawn vehicles,
>>>and cautious elderly drivers.

>>
>>Not in my experience, and not from what I've heard.

>
>
> Selective amnesia again? Remember your cite of
> <http://www.ite.org/traffic/hump.htm> ?


Sure. It states a preference - that (unspecified) bicyclists _prefer_
they don't cross a bike lane. It doesn't say that the humps are "bad
for bicyclists." Again: Reading comprehension!

And having ridden over some speed humps, I found they were not a
problem. In fact, I find bike lanes to be a bigger problem than speed
humps!



--
Frank Krygowski [To reply, remove rodent and vegetable dot com.
Substitute cc dot ysu dot
edu]
post #1088 of 1138

Re: Cities Turning to Bicycles

In article <41642706$1@news.ysu.edu>, Frank Krygowski wrote:
> Brent P wrote:
>
>> In article <4163f534$1@news.ysu.edu>, Frank Krygowski wrote:


>> ... braking in a turn on a bicycle begins to overtax the avialable traction.


> Looks like physics education isn't what it used to be.


Trimming and typical frank insulting.

> It's not the speed that matters; it's the acceleration. If the total of
> your longitudinal plus radial accelerations are within reasonable
> limits, you'll have no problems braking in a curve.


Read the part I trimmed frank. Repeating what I said using different
words is useless.

> 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?

> 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.


Yet you chastise a driver for not knowing the apex speed of a turn until
he was well into the curve. You've insulted a number of people as if they
were not able to do it, and here you show it's difficult, and that you can't
even judge the apex speed yourself before the curve. And judging a curve
is easier on a bicycle than in a car most of the time IMO.

<frank mode> Are you so inexperienced that you cannot determine the
proper speed for the apex of a turn before you enter it? Clueless
newbie. Do you have no ability to look ahead and judge the road?
</fank mode>

> Substantial weight transfer from the rear to the front wheel will
> occur with strong use of the front brake on good traction just before
> entering the curve. When traction is poor or the lean angle is great,
> deceleration cannot be large and therefore, weight transfer will be
> small, so light braking with both wheels is appropriate. If traction
> is miserable, only the rear brake should be used, because although a
> rear skid is recoverable, a front skid is generally not. An exception
> to this is in deep snow, where the front wheel can slide and function
> as a sled runner while being steered.


More well known stuff....

> Braking at maximum lean


> For braking in a curve, take the example of a rider cornering with
> good traction, leaning at 45 degrees, the equivalent of 1G centrifugal
> acceleration. Braking with 1/10g increases the traction demand by one
> half percent. The sum of cornering and braking vectors is the square
> root of the sum of their squares, SQRT(1^2+0.1^2)=1.005 or an increase
> of 0.005. In other words, there is room to brake substantially during
> maximum cornering. Because the lean angle changes as the square of
> the speed, braking can rapidly reduce the angle and allow even more
> braking. For this reason skilled racers nearly always apply both
> brakes into the apex of turns."


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. What
would you do if I brought up autocross skills or something to defend
driving in a certain manner? You'd throw a fit and go off the deep end
about how I was being reckless on public roads and didn't know how to
drive. In fact, that's what occured in this very branch when Nate
mentioned using some racing skills to get around a curve when the apex
speed wasn't known until he got there. You threw a fit about how he (and
then some others) should be more sensible and responsible on public roads
and didn't know how to drive. Yet here you are stating you use a racing
practice as part of road riding that is in the same theme is perfectly ok.

You've been trapped frank. I felt that you would bite on this in this
manner. You've just shown your own hypocrisy. I am sure you'll come back
with how you are only risking yourself on the bicycle or some such. But
that's neither here nor there. You'd throw a fit if I stated I used
autocross skills to take off ramps faster and called you inexperienced
for not using them on public roads.


> Regarding puttering along at sidewalk speeds: Well, we can't really
> prove anything without you and I riding side by side, but no, I'm not
> considered slow. In fact, without knowing anything about your riding
> speed, I wouldn't have any fear of keeping up with you. That comment of
> yours was mistaken and foolish.


So what's the score there frank? You've made what, 150 or more such
comments about me? And you ride fast? What about the old people trying
to cross the street?
post #1089 of 1138

Re: Cities Turning to Bicycles

Alan Baker wrote:

> In article <HoI8d.19620$n%3.2893135@twister.southeast.rr.com>,
> Wayne Pein <wpein@nc.rr.com> 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
post #1090 of 1138

braking in turns

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


Brent P wrote:
> In article <41642706$1@news.ysu.edu>, 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]
post #1091 of 1138

Re: Cities Turning to Bicycles

Tim McNamara <timmcn@bitstream.net> wrote in message news:<m24ql7apmv.fsf@Stella-Blue.local>...
> Nate Nagel <njnagel@flycast.net> writes:
>
> > Tim McNamara wrote:
> >
> >> tetraethylleadREMOVETHIS@yahoo.com (Brent P) writes:
> >>
> >>>In article <m2is9ovqxc.fsf@Stella-Blue.local>, Tim McNamara wrote:
> >>>
> >>>
> >>>>Indeed, my review of some of the traffic management literature
> >>>>(e.g.,
> >>>>http://ops.fhwa.dot.gov/Travel/traff...k/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
post #1092 of 1138

Re: Cities Turning to Bicycles

Wayne Pein wrote:

> Alan Baker wrote:
>
>> In article <HoI8d.19620$n%3.2893135@twister.southeast.rr.com>,
>> Wayne Pein <wpein@nc.rr.com> 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
post #1093 of 1138

Re: Cities Turning to Bicycles

Frank Krygowski wrote:

> Brent P wrote:
>
>> In article <416364f8$1@news.ysu.edu>, 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
post #1094 of 1138

Re: Cities Turning to Bicycles

Alan Baker wrote:

> In article <4b6d2dd6.0410060745.25077fe@posting.google.com>,
> njnagel@hotmail.com (Nate Nagel) wrote:
>
>
>>Arif Khokar <akhokar1234@wvu.edu> wrote in message
>>news:<Z9P8d.6174$sx2.321@news01.roc.ny>...
>>
>>>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/dynaw...okTextView/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

--
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post #1095 of 1138

Re: Cities Turning to Bicycles

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
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