"Steven M. O'Neill" <[email hidden]> wrote in message "]news:[email hidden]...
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one of the six billion said:
"Steven M. O'Neill" <[email hidden]> wrote in message > > It seems silly to want to try. A speed limit is meant to control the damage a motor vehicle > can do, right? Obviously a bicycle (with rider) weighs much much less than car and can do much > much less damage at any given speed. >
Of course a car will do much more damage than a bicycle at 30 mph,
however
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a car can stop faster.
On what planet?
I've never measured it, but I don't follow closely behind cars because on occasions that I have I had a hard time stopping as fast as they did. On top of that I don't believe they were stopping as fast as they could, but I was.
I belive you forgot to subtract out your reaction time. -- Steven O'Neill [email hidden] The true automobile is the bicycle.
Of course a car will do much more damage than a bicycle at 30 mph, however a car can stop faster.
On what planet?
This one, for example.
The limit of braking on a bike is about 0.6g's - beyond that, and you're doing a Superman pose over your bars.
A car can stop considerably faster than that if the driver has half a clue what he or she is doing. And I should mention that not everyone on a bike is capable of a 0.6g stop - many are afraid of over-application of the front brake.
FWIW, when I'm on my tandem I certainly don't worry about going over the bars, and I can generate a considerable amount of stopping power withe they hydraulic front brake. I can easily outstop "half bikes".
Of course a car will do much more damage than a bicycle at 30 mph, however a car can stop faster.
On what planet?
On any planet with a gravitational field. Reason: the center of mass is high on a bicycle, not so on an automobile. When was the last time you saw a car do an endo?
Car with good brakes and tires can decelerate near 1 g. Best a bike can do is about 0.6 g. -- terry morse Palo Alto, CA terrymorse.combikeOpen ↗
"Steven M. O'Neill" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
one of the six billion said:
"Steven M. O'Neill" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
one of the six billion <[email hidden]> wrote: > >"Steven M. O'Neill" <[email hidden]> wrote in message >> >> It seems silly to want to try. A speed limit is meant to control the damage a motor vehicle >> can do, right? Obviously a bicycle (with rider) weighs much much less than car and can do >> much much less damage at any given speed. >> > >Of course a car will do much more damage than a bicycle at 30 mph,
however
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>a car can stop faster.
On what planet?
I've never measured it, but I don't follow closely behind cars because
on
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Quoted message said:
occasions that I have I had a hard time stopping as fast as they did.
On
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top of that I don't believe they were stopping as fast as they could,
but I
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was.
I belive you forgot to subtract out your reaction time. --
Cars have decelerated in front of me much faster than the 2 tenths of a second max that I can start braking from when I first see their brake lights. I've come up to many four way stop signs screaming as fast as I could while coming to a full stop and had cars that were much farther away than I was make it there first. Cars can stop faster than bikes.
Of course a car will do much more damage than a bicycle at 30 mph, however a car can stop faster.
On what planet?
On any planet with a gravitational field. Reason: the center of mass is high on a bicycle, not so on an automobile. When was the last time you saw a car do an endo?
Car with good brakes and tires can decelerate near 1 g. Best a bike can do is about 0.6 g.
Okay, if you know about g's, I'm willing to accept that I'm (perhaps) wrong this time 😉 -- Steven O'Neill [email hidden] The true automobile is the bicycle.
"Steven M. O'Neill" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
one of the six billion said:
"Steven M. O'Neill" <[email hidden]> wrote in message "]news:[email hidden]... > one of the six billion <[email hidden]> wrote: > > > >"Steven M. O'Neill" <[email hidden]> wrote in message > >> > >> It seems silly to want to try. A speed limit is meant to control the damage a motor vehicle > >> can do, right? Obviously a bicycle (with rider) weighs much much less than car and can do > >> much much less damage at any given speed. > >> > > > >Of course a car will do much more damage than a bicycle at 30 mph, however > >a car can stop faster. > > On what planet?
I've never measured it, but I don't follow closely behind cars because
on
Quoted message said:
Quoted message said:
occasions that I have I had a hard time stopping as fast as they did.
On
Quoted message said:
Quoted message said:
top of that I don't believe they were stopping as fast as they could,
but I
Quoted message said:
Quoted message said:
was.
I belive you forgot to subtract out your reaction time. --
Cars have decelerated in front of me much faster than the 2 tenths of a second max that I can start braking from when I first see their brake lights. I've come up to many four way stop signs screaming as fast as I could while coming to a full stop and had cars that were much farther away than I was make it there first. Cars can stop faster than bikes.
Okay, okay. Maybe you're right. But they definitely can't accelerate as quickly. -- Steven O'Neill [email hidden] The true automobile is the bicycle.
In article <[email hidden]>, [email hidden] says...
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I have a client on 145th street in harlen (NYC). The person who does the cleaning and odd jobs (robert) regularly rides a bike. When I'm ther, we regularly "talk bikes". Mayor Mike Bloomberg has (allegedly) instituted a Quota System for the police to serve as a revenue generator.
Just before mothers day, Robert was "pulled over" by an unmarked NYC police car and given a ticket for speeding.
How fast was he going? How was he clocked? It will be a tough fight in any case. NYC has tipped their scales in their favor when it comes to defending yourself against a traffic ticket. The rights you would expect, like discovery, are severely limited, or taken away completely. Your best bet is to keep postponing the ticket as many times as possible and hope that on the time you do show up, the cop does not and the ticket gets thrown out. ----------------- Alex __O _-\<,_ (_)/ (_)
In article <[email hidden]>, [email hidden] says...
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I hope he did not show his Drivers License!
That's a good point. Many people, including some so called judges in traffic court, don't know the law and will convict in such a way that you get points on your drivers license, which is not the case. ----------------- Alex __O _-\<,_ (_)/ (_)
Cars have decelerated in front of me much faster than the 2 tenths of a second max that I can start braking from when I first see their brake lights. I've come up to many four way stop signs screaming as fast as I could while coming to a full stop and had cars that were much farther away than I was make it there first. Cars can stop faster than bikes.
Okay, okay. Maybe you're right. But they definitely can't accelerate as quickly.
Okay, so on a bike I can be uop to cruising speed of 20+ kph inside of a couple of meters, or a few seconds. It takes a car longer to get to cruising -- but, properly operated, it doesn't really take him longer to get up to 20 kph.
I hate to think how many g's are involved in stopping from 20mph to zero in the thickness of helmet foam.
How long the foam crumple takes is what matters. A WAG at some parameters (0.1 s deceleration time, ISO standard 14 kg spherical head) gives about 100 gs. If the foam crush takes twice as long, 50 gs, half as long, 200 g.
In article <[email hidden]>, [email hidden] says...
Quoted message said:
Mark Hickey said:
I hate to think how many g's are involved in stopping from 20mph to zero in the thickness of helmet foam.
How long the foam crumple takes is what matters. A WAG at some parameters (0.1 s deceleration time, ISO standard 14 kg spherical head) gives about 100 gs. If the foam crush takes twice as long, 50 gs, half as long, 200 g.
I believe you moved the decimal point one spot to the right: 20 mph is 29.33 fps, which number is almost the 32 ft/sec/sec. Dropping 32 ft/sec in .1 sec is 10g, not 100g. 29.33 ft/sec is going to be a bit less than that. The mass of the head doesn't affect the deceleration; only the force required to attain it.
-- David Kerber An optimist says "Good morning, Lord." While a pessimist says "Good Lord, it's morning".
Cars have decelerated in front of me much faster than the 2 tenths of a second max that I can start braking from when I first see their brake lights. I've come up to many four way stop signs screaming as fast as I could while coming to a full stop and had cars that were much farther away than I was make it there first. Cars can stop faster than bikes.
Okay, okay. Maybe you're right. But they definitely can't accelerate as quickly.
Okay, so on a bike I can be uop to cruising speed of 20+ kph inside of a couple of meters, or a few seconds. It takes a car longer to get to cruising -- but, properly operated, it doesn't really take him longer to get up to 20 kph.
I'm talking more like 1 or 2 kph. -- Steven O'Neill [email hidden] The true automobile is the bicycle.
I hate to think how many g's are involved in stopping from 20mph to zero in the thickness of helmet foam.
How long the foam crumple takes is what matters. A WAG at some parameters (0.1 s deceleration time, ISO standard 14 kg spherical head) gives about 100 gs. If the foam crush takes twice as long, 50 gs, half as long, 200 g.
Well, figuring I was going around 30 feet per second (just under 10m/s), and figuring that I crushed 1" (2.54cm) of foam, the stop would have taken only about .003 seconds. Factor in the dent I put in the door, and I don't have a clue how long it took. But the numbers look scary, eh?
I have a client on 145th street in harlen (NYC). The person who does the cleaning and odd jobs (robert) regularly rides a bike. When I'm ther, we regularly "talk bikes". Mayor Mike Bloomberg has (allegedly) instituted a Quota System for the police to serve as a revenue generator.
Just before mothers day, Robert was "pulled over" by an unmarked NYC police car and given a ticket for speeding.
Wonder what happens if they pull over a tandem?! Do both people get a ticket?
I have a client on 145th street in harlen (NYC). The person who does the cleaning and odd jobs (robert) regularly rides a bike. When I'm ther, we regularly "talk bikes". Mayor Mike Bloomberg has (allegedly) instituted a Quota System for the police to serve as a revenue generator.
Just before mothers day, Robert was "pulled over" by an unmarked NYC police car and given a ticket for speeding.
Wonder what happens if they pull over a tandem?! Do both people get a ticket?
I have a client on 145th street in harlen (NYC). The person who does the cleaning and odd jobs (robert) regularly rides a bike. When I'm ther, we regularly "talk bikes". Mayor Mike Bloomberg has (allegedly) instituted a Quota System for the police to serve as a revenue generator.
Just before mothers day, Robert was "pulled over" by an unmarked NYC police car and given a ticket for speeding.
Wonder what happens if they pull over a tandem?! Do both people get a ticket?
I hate to think how many g's are involved in stopping from 20mph to zero in the thickness of helmet foam.
From the CPSC test standard: bhsi.orgcpscfinl.htmOpen ↗ (d) Impact attenuation criteria. (1) General. A helmet fails the impact attenuation performance test of this standard if a failure under paragraph (d)(2) of this section can be induced under any combination of impact site, anvil type, anvil impact order, or conditioning environment permissible under the standard, either with or without any attachments, or combinations of attachments, that are provided with the helmet. Thus, the Commission will test for a ``worst case'' combination of test parameters. What constitutes a worst case may vary, depending on the particular helmet involved. (2) Peak acceleration. The peak acceleration of any impact shall not exceed 300 g when the helmet is tested in accordance with Sec. 1203.17 of this standard.
