What exactly does cold pressure mean?

On 11/30/2010 12:07 PM, Steve W. wrote:
> Tom Adams wrote:
>> On Nov 29, 10:57 pm, jim > wrote:
>>> On 11/29/2010 06:57 PM, Steve W. wrote:
>>>
>>>> Tom Adams wrote:
>>>>> I help maintain a Ford E350 used for a vanpool.
>>>>> The door panel spec says that the rear tires require 80 psi.
>>>> That is great IF the tires on the van are the same ones that came from
>>>> the factory. Otherwise it's basically crap.
>>> well, it might be crap for the tire, but it's not for the van's
>>> stability. you certainly don't want the pressure to be less than that
>>> if it's loaded - and vanpools usually are.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>>> The sidewall specs on the rear tires say that the maximum pressure is
>>>>> 80 psi.
>>>> And what does the chart for that tire say the operating pressure should
>>>> be given the load you carry? If your not driving around at the GVW all
>>>> day then you probably also don't need the maximum pressure.
>>>>> So, what does cold pressure mean exactly?
>>>> Cold pressure means NO drive time on the tire. What it reads after the
>>>> van has sat long enough for the tires to reach ambient air temperature.
>>>> So you come out in the AM, Start the engine so it warms up and check the
>>>> tire air pressure. (Don't forget to check the spare)
>>>>> If I check the tires on a cold morning (say 35 degrees) I will end up
>>>>> putting in a few extra pounds more that I would at 70 degrees. But I
>>>>> bet the operating temperature of a tire is largely independent of
>>>>> whether the ambient temperature is 35 or 70.
>>>> That is why you check the pressure at whatever the "normal" temp is for
>>>> the given season. So if you normally see 35-40 degrees during the winter
>>>> check it at 37 degrees. The small amount of change won't make much
>>>> difference.
>>>> Same in the spring and summer. If the "normal" temps are around 80
>>>> degrees then check it at that temp.
>>> --
>>> nomina rutrum rutrum- Hide quoted text -
>>>
>>> - Show quoted text -
>>
>> I think I will thicken the plot a bit.
>>
>> We recently had a bumpy feel in the steering wheel. The mechanics
>> found a "broken belt" in the left rear (probably just a separated
>> belt, but I did not get to eyeball it). Since then I have been
>> trying to figure out any possible causal factors. None of the van
>> drivers recall hitting a pothole at high speed.
>>
>> I had been checking the tires in the morning before the van was
>> driven, noting the pressure differential, and then adjusting the
>> pressure later in the day using the differentials.
>>
>> I plan to start checking pressure at something closer to average
>> ambient, rather than the morning temperature. That will probably
>> knock a pound or two off the maximum pressure when the van is in
>> operation.
>>
>> This van has also has something called Rollgard
>>
>> http://www.amtechsprings.net/portal/
>>
>> I would call Rollgard a spring stiffener but "Rollgard is not a spring
>> stiffener" seems to be Rollgard's defacto motto ;-)
>>
>> I personally think Rollgard is a sick joke. There is no testing
>> data. I read that they tried to get NHTSA to test it but were
>> declined. All they have are testimonial letters on their web site,
>> some of which are laughable. One says Rollgard shortens the turning
>> radius! Rollgard makes drivers feel better because they detect less
>> sway in turns, I think. I don't know if that translates into more or
>> less safety.
>>
>> Anyway, I now have a theory that Rollgard is a tire belt breaker.
>> Makes sense that it would increase the forces on a tire on the bumpy
>> rural roads that we drive on part of our route.
>>
>> Also, I think putting Rollgard on a vehicle makes it harder to sue
>> Ford in the case of a rollover. But this is a conversion van anyway,
>> so that might also make it harder.
>>
>> I think these vans have about average safety overall because of the
>> size advantage, but they are one of most (if not he most) rollover-
>> prone vehicles still made. I think Ford may be paying up for
>> rollovers since they lost a suit a few years ago that left the judge
>> foaming at the mouth at Ford's practices.
>>
>> Equipping a E350 with Rollgard probably makes it harder to extract
>> money from Ford in the case of a rollover or other design-related
>> failure.
>>
>> And, left rear blowouts often lead to fatal rollovers in the E350.
>>
>> BTW, the NHTSA says to use the door panel pressure. 80 psi in the
>> rear tires is probably about right when the van in close to fully
>> loaded:
>>
>> http://www.nhtsa.gov/cars/problems/s...sumerPiece.pdf
>>
>> I don't think the van has sub-standard tires, but I will double-check
>> that.
>
>
> Read the web site. Regardless of what they call it that is nothing more
> than a helper spring.

it can't "help" if both ends float. think about it.


> BUT it looks like it's a composite type so it
> likely doesn't have a lot of power.

material contributes only part of a spring's properties - the dimensions
are key also.


>
> ALL vans and large vehicles are top heavy, They are ALL prone to roll
> over if they are not driven properly.
> The main reason why all of these vehicles are rolling over has to do
> with a lack of respect of the operator for the vehicles limits.

nope, it's their design. leaf springs have very limited lateral
stability, thus if you're forced to transition from a lean in one
direction to a lean in the other, like if you're avoiding an accident or
trying to control the wobble cause by a flat, you can have an harmonic
reinforcement of it's roll to the point where it flips. fundamental
problem.


>
> Take a Jeep CJ. You can take them off road and darn near climb trees and
> they won't roll over. Side hills are not a problem IF YOU GO SLOw. When
> they came out they were popular with drivers who had used them in combat
> and who respected they way they handled. The next generation was raised
> with them and were taught how they should be driven, BUT they didn't buy
> a lot of them when the older ones started failing. They wanted
> B I G G E R vehicles and moved to large cars and wagons. Their kids
> didn't get taught on narrow wheelbase vehicles, they were taught on huge
> land yachts that wouldn't roll over unless you were really stupid. So
> those kids and their parents more or less forgot how to deal with the
> smaller vehicles.
> So did their kids.
> Then 4X4s became popular again. What happens? These folks who had never
> though about vehicle dynamics bought up a ton of Jeeps, Small SUVs, Vans
> and figured that they could drive them just like they did the cars they
> had before. WRONG. They are not meant to be driven down a twisty road at
> 60 mph and tossed into corners like a car.
>
> End result, They roll over. Then these folks complain about it and the
> media (who were raised the same way) think that the problem is in the
> vehicles design. The truth is that most of the people who roll vehicles
> shouldn't be driving that type of vehicle in the first place.

no dude, it's the design. in this day and age, there's no excuse for
continuing to produce vehicles with KNOWN fundamentals like this. the
only reason they still are is cost - and the fact that the auto
manufacturers can show up in d.c. with a couple of brown envelopes and
make all nhtsa interest in addressing this disappear.


>
> But since pointing a finger at the person and saying "You're an idiot
> for driving that way" is no longer an acceptable thing to do and
> personal responsibility is a forgotten concept, it's so much easier to
> say "It's (name company with money) fault, they made (insert product
> being used by an idiot here)"
>
> Think about this one.
> Everyone makes fun of the stickers that say things like
> "Do not use in the shower/bath" stuck on a hair drier or curling iron
> that is wall powered. Many look at that and say DUH! Who would be dumb
> enough to do that, it's just common sense.
> That sticker wouldn't be there if that didn't happen at some point and a
> Judge and jury decided that the company that made it was at fault for
> not warning the user about that very danger!!!
>
> Go take a look at the visor warning tags that have to be on every 4X4
> and SUV now. The ones that warn you that these vehicles handle different
> and that you have to be careful. Care to guess why they are there?
>
>
> How about that maximum pressure warning on those tires. Think it is
> there because the maker got sued at one time because Billy Bob decided
> that 80 PSI just wasn't enough and tried to put 120 PSI in them "Like a
> REAL TRUCK TIRE"
>


--
nomina rutrum rutrum

On 11/30/2010 03:45 PM, Tom Adams wrote:
> On Nov 30, 4:27�pm, "Steve > wrote:
>> Tom Adams wrote:
>>>> ALL vans and large vehicles are top heavy, They are ALL prone to roll
>>>> over if they are not driven properly.
>>>> The main reason why all of these vehicles are rolling over has to do
>>>> with a lack of respect of the operator for the vehicles limits.
>>
>>> You can believe all that if you want, but you ever happen to ride in
>>> an E350 just make sure your wife knows calls a personal injury lawyer
>>> if it rollovers.
>>
>> I drive them every day, Ambulaces and ambulette types. As well as the
>> ones in my department.
>> Take a look at the next ambulance you see. It is probably either an
>> E350 or a GM 3500. Pretty much what gets used.
>>
>> Think that they don't get driven HARD and at far above highway speeds?
>>
>> BUT they are also driven by people who are TRAINED how to drive them.
>> They slow down for corners, pay attention to curves and more.
>>
>>
>>
>>> It's true that some vehicles are more rollover prone than others. �But
>>> there
>>> are ways to measure rollover propensity and the E350 is at least tied
>>> for
>>> the worst one still made.
>>
>>> Heck, Ford does not even sell the 2009 E350 passenger van without Roll
>>> Stability
>>> Control. �But we have a conversion van, a converted 2009 E350 *cargo*
>>> van without the
>>> stability control that is optional on the cargo van and standard on
>>> the passenger van.
>>
>> Never had it on any that I drove. And never had a problem as long as you
>> drive the vehicle within it's limits.
>>
>>
>>
>>> The fatality statistics for E350s that have rear tire blowouts at
>>> highway speeds are really outrageous.
>>
>>> Read this but skip the sob stories and just read the parts where
>>> Ford's whistleblowers and the accident reconstruction experts are
>>> being interviewed:
>>
>> And read about how NBC and CBS RIGGED stories about GM gas tanks and
>> other vehicle problems.
>
> So what? I was trying to direct your attention to the substance of
> the stories, the wistleblowers, the accident reconstrution experts,
> the experts who measure and analyze how roll-over prone these vehicles
> are.
>
> Who would care about the medium?
>
> I am sure that every news outlet has made mistakes. So you always
> have to evaluate the actual information, not the medium.
>
> Anyway, your resorting to this kind of stuff is an indicator that you
> can't handle the facts I am throwing at you.
>
> Ford is losing in court because if info directly from Ford. It has
> nothing to do with NBC or CBS.

indeed - they knew the problem, decided to proceed anyway, and pockeed
the profits afforded by cheaper production costs. now they should pay.


>
>>
>> If you have such a fear of driving them then get out of the job. Simple.
>>
>
> I don't fear driving them. As I said earlier, I think they have
> overall average safety. They have also have a design advantage: size.
>
> I posted here in an attempt to understand how to maintain the van
> better. It's obvious that the safety of these vans is very sensitive
> to maintenance.
>
> The ambulances probably have a different load distribution than the
> usual 15 passeger van. That should (1) reduce the load on the left
> rear tire reducing the chance of the kind of tire failure we had (2)
> make the load more evenly distributed making handling easier (3)
> reduce the oversteering problen caused by having 4 passengers seated
> behind the rear wheel.
>
> My van is also safer than the old 15 passenger vans. We have a center
> aisle that evens out the load and our van has only has 13 seats.
>
> Also, transit vans have a good safety record, probably because they
> are better maintained, newer, and have more rested drivers. The
> problems seem to be with poorly maintained older vans on longer hauls.


--
nomina rutrum rutrum

On 11/30/2010 01:30 PM, Steve W. wrote:
> Tom Adams wrote:
>>
>> "Vehicles ought to be able to slide sideways on dry, smooth pavement
>> without rolling over. The Ford and Chrysler 15-passenger vans flunk
>> this test."
>>
>> This is a good write-up that is more technically-oriented than the 60
>> Minutes report:
>>
>> http://www.ammonslaw.com/publication...-passenger-van
>>
>> The problem for Ford is that their internal documents, whistleblowers,
>> and employees under oath indicate a design problem.
>>
>> I guess its a matter of degree as to what is and is not a design flow.
>
>
> BULLSH*T....
>
> I can roll ANY vehicle in a sideways slide on dry pavement.

then you've never driven one that's been properly designed. believe me,
you'll NEVER roll my civic on dry pavement - i've tried and have had it
sideways at 70 before now. no roll.


> I have seen an Abrams tank that went over due to being cranked around
> hard on dry pavement.

yeah, many tracked vehicles will do that - because despite their weight,
their suspension is /really/ soft and they have no ackermann or anything
that helps them track properly.


>
> Ever seen a race event, Think that an Indy car which will stick to the
> road with a LOT better grip than any passenger car ever will have won't
> roll? Happens all the time.

indy don't roll unless they touch something dude. man up to the facts.


--
nomina rutrum rutrum

jim beam wrote:
> On 11/30/2010 01:30 PM, Steve W. wrote:
>> Tom Adams wrote:
>>>
>>> "Vehicles ought to be able to slide sideways on dry, smooth pavement
>>> without rolling over. The Ford and Chrysler 15-passenger vans flunk
>>> this test."
>>>
>>> This is a good write-up that is more technically-oriented than the 60
>>> Minutes report:
>>>
>>>
>>> http://www.ammonslaw.com/publication...-passenger-van
>>>
>>> The problem for Ford is that their internal documents, whistleblowers,
>>> and employees under oath indicate a design problem.
>>>
>>> I guess its a matter of degree as to what is and is not a design flow.
>>
>>
>> BULLSH*T....
>>
>> I can roll ANY vehicle in a sideways slide on dry pavement.
>
> then you've never driven one that's been properly designed. believe me,
> you'll NEVER roll my civic on dry pavement - i've tried and have had it
> sideways at 70 before now. no roll.

Fine take it up to 100 and snap it HARD left. On good pavement with good
tires it will go over.

>
>
>> I have seen an Abrams tank that went over due to being cranked around
>> hard on dry pavement.
>
> yeah, many tracked vehicles will do that - because despite their weight,
> their suspension is /really/ soft and they have no ackermann or anything
> that helps them track properly.
>
>>
>> Ever seen a race event, Think that an Indy car which will stick to the
>> road with a LOT better grip than any passenger car ever will have won't
>> roll? Happens all the time.
>
> indy don't roll unless they touch something dude. man up to the facts.

I've been there when it has happened, they didn't touch anything, just
went sideways and rolled.

--
Steve W.

On 11/30/2010 09:11 PM, Steve W. wrote:
> jim beam wrote:
>> On 11/30/2010 01:30 PM, Steve W. wrote:
>>> Tom Adams wrote:
>>>>
>>>> "Vehicles ought to be able to slide sideways on dry, smooth pavement
>>>> without rolling over. The Ford and Chrysler 15-passenger vans flunk
>>>> this test."
>>>>
>>>> This is a good write-up that is more technically-oriented than the 60
>>>> Minutes report:
>>>>
>>>>
>>>> http://www.ammonslaw.com/publication...-passenger-van
>>>>
>>>> The problem for Ford is that their internal documents, whistleblowers,
>>>> and employees under oath indicate a design problem.
>>>>
>>>> I guess its a matter of degree as to what is and is not a design flow.
>>>
>>>
>>> BULLSH*T....
>>>
>>> I can roll ANY vehicle in a sideways slide on dry pavement.
>>
>> then you've never driven one that's been properly designed. believe me,
>> you'll NEVER roll my civic on dry pavement - i've tried and have had it
>> sideways at 70 before now. no roll.
>
> Fine take it up to 100 and snap it HARD left. On good pavement with good
> tires it will go over.

dude, you've never driven an 89 civic. all you're doing is presuming
and bull****ting based on /your/ limited experience driving flawed
vehicles that /would/ do this.

besides, my sideways at 70 was courtesy of some sheetrock that had
fallen off a truck and was mid-air right in front of me. full sideways
left followed by a full-over-correction right, so she didn't even flip
on the transition.* /very/ few cars are that stable.

* there are two types of stability tests - the "j-curve", which the
vehicles you're talking about can't even do, then the "s-curve", which
is much more exacting because on transition from leaning one way, you
steer into the next bend in the opposite direction, so the "flip" motion
is the compound of the dive into the curve PLUS, the bounce from the
previous one. even today, this is hard for many vehicles to pass, and
the vehicles being discussed above don't get anywhere near it. saying
this is something the driver should live with, as you're doing, is
ridiculous as it doesn't take into account the real needs of a driver in
an emergency.


>
>>
>>
>>> I have seen an Abrams tank that went over due to being cranked around
>>> hard on dry pavement.
>>
>> yeah, many tracked vehicles will do that - because despite their weight,
>> their suspension is /really/ soft and they have no ackermann or anything
>> that helps them track properly.
>>
>>>
>>> Ever seen a race event, Think that an Indy car which will stick to the
>>> road with a LOT better grip than any passenger car ever will have won't
>>> roll? Happens all the time.
>>
>> indy don't roll unless they touch something dude. man up to the facts.
>
> I've been there when it has happened, they didn't touch anything, just
> went sideways and rolled.

uh huh. just like my civic rolled 'cos you said it would. oh, wait, it
won't.


--
nomina rutrum rutrum

On 11/30/2010 09:34 PM, jim beam wrote:
> On 11/30/2010 09:11 PM, Steve W. wrote:
>> jim beam wrote:
>>> On 11/30/2010 01:30 PM, Steve W. wrote:
>>>> Tom Adams wrote:
>>>>>
>>>>> "Vehicles ought to be able to slide sideways on dry, smooth pavement
>>>>> without rolling over. The Ford and Chrysler 15-passenger vans flunk
>>>>> this test."
>>>>>
>>>>> This is a good write-up that is more technically-oriented than the 60
>>>>> Minutes report:
>>>>>
>>>>>
>>>>> http://www.ammonslaw.com/publication...-passenger-van
>>>>>
>>>>>
>>>>> The problem for Ford is that their internal documents, whistleblowers,
>>>>> and employees under oath indicate a design problem.
>>>>>
>>>>> I guess its a matter of degree as to what is and is not a design flow.
>>>>
>>>>
>>>> BULLSH*T....
>>>>
>>>> I can roll ANY vehicle in a sideways slide on dry pavement.
>>>
>>> then you've never driven one that's been properly designed. believe me,
>>> you'll NEVER roll my civic on dry pavement - i've tried and have had it
>>> sideways at 70 before now. no roll.
>>
>> Fine take it up to 100 and snap it HARD left. On good pavement with good
>> tires it will go over.
>
> dude, you've never driven an 89 civic. all you're doing is presuming and
> bull****ting based on /your/ limited experience driving flawed vehicles
> that /would/ do this.
>
> besides, my sideways at 70 was courtesy of some sheetrock that had
> fallen off a truck and was mid-air right in front of me.

the point being that this was a full blown decapitation prevention
emergency - there was no "test" or playing chicken because i didn't want
to dirty the detailing i'd just paid for...



> full sideways
> left followed by a full-over-correction right, so she didn't even flip
> on the transition.* /very/ few cars are that stable.
>
> * there are two types of stability tests - the "j-curve", which the
> vehicles you're talking about can't even do, then the "s-curve", which
> is much more exacting because on transition from leaning one way, you
> steer into the next bend in the opposite direction, so the "flip" motion
> is the compound of the dive into the curve PLUS, the bounce from the
> previous one. even today, this is hard for many vehicles to pass, and
> the vehicles being discussed above don't get anywhere near it. saying
> this is something the driver should live with, as you're doing, is
> ridiculous as it doesn't take into account the real needs of a driver in
> an emergency.
>
>
>>
>>>
>>>
>>>> I have seen an Abrams tank that went over due to being cranked around
>>>> hard on dry pavement.
>>>
>>> yeah, many tracked vehicles will do that - because despite their weight,
>>> their suspension is /really/ soft and they have no ackermann or anything
>>> that helps them track properly.
>>>
>>>>
>>>> Ever seen a race event, Think that an Indy car which will stick to the
>>>> road with a LOT better grip than any passenger car ever will have won't
>>>> roll? Happens all the time.
>>>
>>> indy don't roll unless they touch something dude. man up to the facts.
>>
>> I've been there when it has happened, they didn't touch anything, just
>> went sideways and rolled.
>
> uh huh. just like my civic rolled 'cos you said it would. oh, wait, it
> won't.
>
>


--
nomina rutrum rutrum

On 11/30/2010 12:55 PM, Tom Adams wrote:
> On Nov 30, 2:48�pm, jim > wrote:
>> On 11/30/2010 09:23 AM, Tom Adams wrote:
>>
>>
>>
>>
>>
>>> On Nov 29, 10:57 pm, jim > �wrote:
>>>> On 11/29/2010 06:57 PM, Steve W. wrote:
>>
>>>>> Tom Adams wrote:
>>>>>> I help maintain a Ford E350 used for a vanpool.
>>
>>>>>> The door panel spec says that the rear tires require 80 psi.
>>
>>>>> That is great IF the tires on the van are the same ones that came from
>>>>> the factory. Otherwise it's basically crap.
>>
>>>> well, it might be crap for the tire, but it's not for the van's
>>>> stability. you certainly don't want the pressure to be less than that
>>>> if it's loaded - and vanpools usually are.
>>
>>>>>> The sidewall specs on the rear tires say that the maximum pressure is
>>>>>> 80 psi.
>>
>>>>> And what does the chart for that tire say the operating pressure should
>>>>> be given the load you carry? If your not driving around at the GVW all
>>>>> day then you probably also don't need the maximum pressure.
>>
>>>>>> So, what does cold pressure mean exactly?
>>
>>>>> Cold pressure means NO drive time on the tire. What it reads after the
>>>>> van has sat long enough for the tires to reach ambient air temperature.
>>>>> So you come out in the AM, Start the engine so it warms up and check the
>>>>> tire air pressure. (Don't forget to check the spare)
>>
>>>>>> If I check the tires on a cold morning (say 35 degrees) I will end up
>>>>>> putting in a few extra pounds more that I would at 70 degrees. But I
>>>>>> bet the operating temperature of a tire is largely independent of
>>>>>> whether the ambient temperature is 35 or 70.
>>
>>>>> That is why you check the pressure at whatever the "normal" temp is for
>>>>> the given season. So if you normally see 35-40 degrees during the winter
>>>>> check it at 37 degrees. The small amount of change won't make much
>>>>> difference.
>>
>>>>> Same in the spring and summer. If the "normal" temps are around 80
>>>>> degrees then check it at that temp.
>>
>>>> --
>>>> nomina rutrum rutrum- Hide quoted text -
>>
>>>> - Show quoted text -
>>
>>> I think I will thicken the plot a bit.
>>
>>> We recently had a bumpy feel in the steering wheel. �The mechanics
>>> found a "broken belt" in the left rear (probably just a separated
>>> belt, but I did not get to eyeball it). � Since then I have been
>>> trying to figure out any possible causal factors. �None of the van
>>> drivers recall hitting a pothole at high speed.
>>
>>> I had been checking the tires in the morning before the van was
>>> driven, noting the pressure differential, and then adjusting the
>>> pressure later in the day using the differentials.
>>
>>> I plan to start checking pressure at something closer to average
>>> ambient, rather than the morning temperature. �That will probably
>>> knock a pound or two off the maximum pressure when the van is in
>>> operation.
>>
>>> This van has also has something called Rollgard
>>
>>> http://www.amtechsprings.net/portal/
>>
>>> I would call Rollgard a spring stiffener but "Rollgard is not a spring
>>> stiffener" seems to be Rollgard's defacto motto ;-)
>>
>> the reason it's not a "spring stiffener" is that the two moving arms on
>> each end allow it to float. �but that also means the thing is doing
>> absolutely nothing unless one of those ends bottoms against something.
>> bottom line, you're just carrying extra weight and potentially rubbing
>> fatigue initiation points into your real springs - i'd get rid of it
>> immediately.
>
> This is a transit authority van, so I cannot easily get changes made.
>
> BTW, I called the makers of Rollgard and they said it was compatible
> with ESC.

sure it is - it does absolutely nothing!


> Our van does not have ESC, but its an option and the owner manual of
> the van
> covers it. The manual has a strongly worded warning about
> modifications of the
> suspension system.

with good reason. spring fatigue is a serious issue. the mountings for
those "roll guard" things will rub, cause stress risers, and thus,
initiate fatigue.


>
> (I was calling about ESC because I managed to get the State of NC to
> start getting
> the ESC option for all new vans and I was concerned that they might
> still put Rollgard
> on those ESC-equippef vans.)

the way it works is this: the sales droid shows up at the state's motor
dept and says he has something to sell. if he's lucky, he can make the
sale because the motor dept dude actually believes him. but if he's
lucky in another way, the two can, ahem, "have a meeting of the minds"
and agree that whatever is being sold will be bought, and that the motor
dept dude gets to enjoys certain after-sales "benefits". happens all
the freakin' time.


>
> Basically, the makers of Rollgard are obvously ignorant boobs.

not as ignorant as the people that install them.


>
>>
>>
>>
>>
>>
>>
>>
>>> I personally think Rollgard is a sick joke. �There is no testing
>>> data. �I read that they tried to get NHTSA to test it but were
>>> declined. �All they have are testimonial letters on their web site,
>>> some of which are laughable. �One says Rollgard shortens the turning
>>> radius! �Rollgard makes drivers feel better because they detect less
>>> sway in turns, I think. �I don't know if that translates into more or
>>> less safety.
>>
>>> Anyway, I now have a theory that Rollgard is a tire belt breaker.
>>> Makes sense that it would increase the forces on a tire on the bumpy
>>> rural roads that we drive on part of our route.
>>
>>> Also, I think putting Rollgard on a vehicle makes it harder to sue
>>> Ford in the case of a rollover. �But this is a conversion van anyway,
>>> so that might also make it harder.
>>
>>> I think these vans have about average safety overall because of the
>>> size advantage, but they are one of most (if not he most) rollover-
>>> prone vehicles still made. �I think Ford may be paying up for
>>> rollovers since they lost a suit a few years ago that left the judge
>>> foaming at the mouth at Ford's practices.
>>
>>> Equipping a E350 with Rollgard probably makes it harder to extract
>>> money from Ford in the case of a rollover or other design-related
>>> failure.
>>
>>> And, left rear blowouts often lead to fatal rollovers in the E350.
>>
>>> BTW, the NHTSA says to use the door panel pressure. �80 psi in the
>>> rear tires is probably about right when the van in close to fully
>>> loaded:
>>
>>> http://www.nhtsa.gov/cars/problems/s...5-PassengerVan...
>>
>>> I don't think the van has sub-standard tires, but I will double-check
>>> that.
>>
>> all tires are /not/ created equal. �get the best quality tires for this
>> thing - you have multiple lives at stake - especially if you have a rear
>> blowout and this thing becomes unstable and rolls. �commuter vans are
>> terrible in the rollover stability department.
>>
>> --
>> nomina rutrum rutrum- Hide quoted text -
>>
>> - Show quoted text -- Hide quoted text -
>>
>> - Show quoted text -
>


--
nomina rutrum rutrum

If a tire blows out, who knows what will happen?
cuhulin

> If the door decal specifies 80psi and the tire sidewall max
> is 80psi, I would suspect someone has installed a reduced
> load range tire on the van.
> Lugnut

Not necessarily; it's perfectly acceptable to have the sticker
pressure the same as max tire pressure. And this is often the case
when a tire is required to carry near its max capacity.

Having a "max" pressure of 80 psi does not mean the tire will blow at
81 psi, or sustain damage. In fact, most tires do not blow till
atleast 2 - 3 times over its max pressure, sometimes up to 5 on
commercial H+ rated tires (500+ psi). For LT tires, 80 psi, or load E
rating, is the max you can go. Unless you want to convert your van to
19.5" wheels and run commercial tires.


As both an engineer and commerical driver, I would say a MAJORITY of
15 passenger van rollovers are the operator's fault. Most people don't
think twice when piloting a van carrying 3000 lbs of human cargo; they
accelerate, stop, and swerve the same as they would in their Accord.
Of course that's asking for trouble! Consider this: there're millions
of big rigs and commercial busses runing 100,000s miles a year out
there, and every singe one of them has a MUCH higher CG than even a
fully loaded van (think tanker, or meat truck). Should we ban all of
them because they're prone to roll overs?

Your typical tour coach has 10,000 lbs of people riding 6 feet off the
ground, with a vehicle width of only 1.5 times wider than a van. What
do you think would happen if the coach driver swerves or performs a
"fish hook manuver" at 75 mph? Truth is, bus drivers rarely have to do
that. If 15 passenger van drivers learn to 1) not drive so fast, and
2) not follow so closely, then him or her wouldn't have to either.

The other thing is maintenance. Safety studies discovered 57% of 15
passenger van crashes had one or more tires severely under-inflated.
Is that a design flaw or driver neglegance. Since 15 pass van tires
are already near their max weight capacity, any underinflation is
fatal. I can gurantee that if every 15p van has its tires at 60 psi
fron / 80 psi rear, blowouts will be close to none.

The sad reality is, your typical church driver or sports coach know
nothing about the above, and that's why we hear these tragic stories
of multiple children injured or killed in 15 pass van crashes. I'm
not saying the design of these vans are perfect, or even good, but
they're far from the death traps that media has led us into believing.

On Dec 1, 8:51*pm, charter > wrote:

>
> The sad reality is, your typical church driver or sports coach know
> nothing about the above, and that's why we hear these tragic stories
> of multiple children injured or killed in 15 pass van crashes. *I'm
> not saying the design of these vans are perfect, or even good, but
> they're far from the death traps that media has led us into believing.
__________________
Of course not - GAWWWHHHHD will make sure this church van gets us
there safely!!!! Knowledge of tire pressure? What's that? Remember
what happened to Adam & Eve regarding knowledge? Ejoocation
schmeducation - GAWWWHHDD will take care of everything!!
AlleluUUUUUUUUUUjiah!!!

(LSHISMP!!)

-ChrisCoaster