# Re: Bridgestone Ecopia EP-03 Tires



## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

Well I had one in my hand today and then it was taken
away. I received a call late last week saying they
found a set of them hidden in a warehouse in
California, cool! I received a call this morning
informing me they had arrived. Having been caught off
guard without wheels I said I'd just come by and pay
for them and take them so they wouldn't be taking up
space in their store after all I had gone through to
get them.

I was on my way to get them and I received another
call, they started looking closely at them and they
discovered the date code on two of them was for 2000
and the other two were for 2001. I'm not sure if it
was a legal thing, or just corporate policy but they
wouldn't sell me a tire that was that old. I asked if
I could at least come look at them after all that,
they said yes. I held one in my hand and examined the
sidewall. Sure enough molded in to the side wall were
the words "For Electric Vehicle Use Only" I'm sure
they had some extra load capacity built in, they were
51psi tires. The tread looked all sorts of funky, this
is the tire efficient EV wet dreams are made out of.
It was in my hand and I couldn't take it.

So we're back to the drawing board, but I'm assured I
will eventually get a good set of them... I just have
the feeling they are going to have to come from Japan
now for real. I really really want to put a set on a
car and see how they compare, I have high
expectations.

Later,
Rick
92 Saturn SC conversion
AZ Alt Fuel Plates "ZEROGAS"



____________________________________________________________________________________
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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*


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## EVDL List (Jul 27, 2007)

*RE: Bridgestone Ecopia EP-03 Tires*


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

True, old tires are very dangerous. Even if they don't blow out, they get hard and have poor traction. I am ashamed to admit that I actually caused an accident this way. I have an old set of tires on my Corvair truck too. They don't have many miles on them, but they're about 10 years old. One of them blew out last week while the truck was parked.

I have been looking at these tires for my EV project. 

http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Potenza+RE92&vehicleSearch=false&partnum=665SR4RE92&fromCompare1=yes&place=0

Sorry for the long link. I have been looking at these because they are as narrow and as low profile as I can find for a 14" tire.

Brian



> ---- "Joseph T. " <[email protected]> wrote:
> 
> =============
> As terribly ridiculous it sounds, it's true unfortunately. Tires that
> ...


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

>From: Brian Jackson <[email protected]>
>Reply-To: [email protected]
>To: [email protected]
>CC: "Joseph T. " <[email protected]>
>Subject: Re: Bridgestone Ecopia EP-03 Tires
>Date: Thu, 26 Jul 2007 23:45:16 -0700
>
>True, old tires are very dangerous. Even if they don't blow out, they get 
>hard and have poor traction. I am ashamed to admit that I actually caused 
>an accident this way. I have an old set of tires on my Corvair truck too. 
>They don't have many miles on them, but they're about 10 years old. One of 
>them blew out last week while the truck was parked.
>
>I have been looking at these tires for my EV project.
>
>http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Potenza+RE92&vehicleSearch=false&partnum=665SR4RE92&fromCompare1=yes&place=0
>
>Sorry for the long link. I have been looking at these because they are as 
>narrow and as low profile as I can find for a 14" tire.
>
>Brian
>
>
Brian - do you know the rolling resistance factor for RE92's ? I don't 
think I've ever seen them in a chart of low rolling resistance tires.

If you look at the GreenSeal paper, two of the lowest tires ( the 
Bridgestone B381's and the Sumitomo HTR 200's are available in stock at 
TireRack in 14 inch sizes - although not as narrow as the RE92 you are 
looking at.

Why do you want the narrowest tire? Do you need a tire that small to fit 
in your wheel well?

If not, it is more important to have a low rolling resistance tire. This 
depends on the material and construction of the tire, not its width.


Phil Marino

_________________________________________________________________
http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_pcmag_0507


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*



> Joseph T. wrote:
> > As terribly ridiculous it sounds, it's true unfortunately. Tires that
> > are over 6 years old have aged, believe it or not from just sitting
> > there. The tires, despite little/no use, have deteriated enough to
> ...


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

Certainly tires can be used for much longer, but I think the point worth 
taking away is that after several years of use or sitting, it is worth 
inspecting them more regularly for signs of cracking, bulging, or 
seperation.

- Kip


----- Original Message ----- 
From: "Lee Hart" <[email protected]>
To: <[email protected]>
Sent: Thursday, July 26, 2007 10:31 PM
Subject: Re: Bridgestone Ecopia EP-03 Tires




> > Joseph T. wrote:
> >> As terribly ridiculous it sounds, it's true unfortunately. Tires that
> >> are over 6 years old have aged, believe it or not from just sitting
> >> there. The tires, despite little/no use, have deteriated enough to
> ...


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

The 165/65-14 RE92's are low rolling resistance. They are the stock tire 
for the Honda Insight. Kinda' loud at high pressure (I run mine at 
52psi), but boy to they roll...
I got 70k miles out of my first set.
cheers,
Andrew



> Phil Marino wrote:
> >
> >
> >
> ...


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*



> Brian Jackson wrote:
> > True, old tires are very dangerous. Even if they don't blow out, they
> > get hard and have poor traction. I am ashamed to admit that I
> > actually caused an accident this way. I have an old set of tires on
> ...


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

It was just brought to my attention that the Ecopia's
I'm trying to get are load rated 89S or 1279lbs!
That's a lot for a 14" tire.

Rick



____________________________________________________________________________________
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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

That may just mean they used more rubber and its probably a little heavier than a similarly sized tire.

----- Original Message -----
From: Ricky Suiter <[email protected]>
Date: Friday, July 27, 2007 11:38 am
Subject: Re: Bridgestone Ecopia EP-03 Tires
To: EV List <[email protected]>

> It was just brought to my attention that the Ecopia's
> I'm trying to get are load rated 89S or 1279lbs!
> That's a lot for a 14" tire.
> 
> Rick
> 
> 
> 
> ____________________________________________________________________________________
> Need a vacation? Get great deals
> to amazing places on Yahoo! Travel.
> http://travel.yahoo.com/
> 
>


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

Tire rolling resistance relative to width.

Because the narrower tire ends up with more weight per square inch and
an therefore a larger flatspot and higher force to multiply by the
friction coeffient it tends to balance out with the narrower but longer
patch. But a large change either direction from optimal is noticable.

My friends raced a highly prepared honda civic in SCCA with cantaliver
tires. These 2 brothers did this as a hobby after their first jobs of
being on the NISSAN race team (1 driver, 1 mechanic type) Anyhow, they
really did a lot of testing. The wider tires add wind resistance and
rotateing mass and wouldn't warm up and stick, the narrower tires were
over heated and slid around to much. Their was an optimum point.

Test it. :-(

The key to a low rolling resistance tire is not as simple as people
assume. Mainly a more flexible rubber that doesn't just rub off by
adding silica, the ability to be kept rounder with more air pressure
without being made stiffer by using a higher thread count of more
flexible threads in the casing and a diagonal ply arrangement on the
side-walls to allow them to flex without absorbing too much energy. As
the tire goes around the side walls are forced to flex and unflex and
the road pushing against the rolling tire forming a teardrop distortion
that adds drag. The addition of silica also gives the rubber an
interesting property kinda like old car wax in reverse. As it is sheared
off,it's coefficient of friction increases.

The Caseing is really important, it is a waste of time to put fancy
rubber on a poor foundation. Once you have a good foundation they even
have tried variable chemistries in a tire. a stripe down the center
having a higher silica content than the edges. As brakes are applied or
the vehicle corners hard, the grip goes up.

Ground level Ozone hurts rubber. What use to last 10 years lasts 5 now! 
DOT* Race tires where it really matters are wrapped, are almost not
saleable after a year. They and usully mounted and shaved on a lathe
before use(this takes of about 1/2 the tread, getting rid of the rubber
on the surface that is contaminated with mold release and makes the
tread stiffer so it lasts longer. go figure)

DOT* Department of transportation. Tires approved for use on roads but
have really soft rubber on them and are used for SCCA racing.


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## EVDL List (Jul 27, 2007)

*RE: Bridgestone Ecopia EP-03 Tires*

Oh yes, width will definitely impact the rolling resistance.

The Bridgestone Potenza RE92 are the OEM tire specified for the
Prius from years 2001 to 2003, they used the XL variant, which
allows a higher load rating than the standard RE92.

They certainly have a low rolling resistance.

In fact, I switched from the RE92 to HTR-200 on my Prius
and noticed an MPG hit (which is normal when putting new tires 
on a car, as the increased amount of rubber means more energy
wasted in friction during compression)

Hth,

Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [email protected]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Phil Marino
Sent: Friday, July 27, 2007 5:48 AM
To: [email protected]
Subject: Re: Bridgestone Ecopia EP-03 Tires




>From: Brian Jackson <[email protected]>
>Reply-To: [email protected]
>To: [email protected]
>CC: "Joseph T. " <[email protected]>
>Subject: Re: Bridgestone Ecopia EP-03 Tires
>Date: Thu, 26 Jul 2007 23:45:16 -0700
>
>True, old tires are very dangerous. Even if they don't blow out, they 
>get hard and have poor traction. I am ashamed to admit that I actually 
>caused an accident this way. I have an old set of tires on my Corvair truck
too.
>They don't have many miles on them, but they're about 10 years old. One 
>of them blew out last week while the truck was parked.
>
>I have been looking at these tires for my EV project.
>
>http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=
>Potenza+RE92&vehicleSearch=false&partnum=665SR4RE92&fromCompare1=yes&pl
>ace=0
>
>Sorry for the long link. I have been looking at these because they are 
>as narrow and as low profile as I can find for a 14" tire.
>
>Brian
>
>
Brian - do you know the rolling resistance factor for RE92's ? I don't
think I've ever seen them in a chart of low rolling resistance tires.

If you look at the GreenSeal paper, two of the lowest tires ( the
Bridgestone B381's and the Sumitomo HTR 200's are available in stock at
TireRack in 14 inch sizes - although not as narrow as the RE92 you are
looking at.

Why do you want the narrowest tire? Do you need a tire that small to fit 
in your wheel well?

If not, it is more important to have a low rolling resistance tire. This
depends on the material and construction of the tire, not its width.


Phil Marino

_________________________________________________________________
http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migratio
n_HM_mini_pcmag_0507


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## EVDL List (Jul 27, 2007)

*RE: Bridgestone Ecopia EP-03 Tires*

If a tire is good for 80,000 miles, and the car drives 12,000 miles per year, then the tire will have to live for a little more than 6 years. However, if the tire is 6 years old already, then the tire is pretty much trash before it ever gets on the wheel. Even if it has a few miles left in it, the retailer can not sell it like that.

Brian
>
>
> ______________________________________________________________________
> ______________ Looking for a deal? Find great prices on flights and 
> hotels with Yahoo! FareChase.
> http://farechase.yahoo.com/
>
>


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

Phil,

The reason I want a narrow tire is that a narrower tire will usually have a lower rolling resistance. This assumes that the tire it's being compared to is made of the same rubber compound and has the same tread. I will take a look at the tires you listed. Since they are listed as low resistance, they probably have a lower rolling resistance. 

Brian


>Brian
>
>
Brian - do you know the rolling resistance factor for RE92's ? I don't 
think I've ever seen them in a chart of low rolling resistance tires.

If you look at the GreenSeal paper, two of the lowest tires ( the 
Bridgestone B381's and the Sumitomo HTR 200's are available in stock at 
TireRack in 14 inch sizes - although not as narrow as the RE92 you are 
looking at.

Why do you want the narrowest tire? Do you need a tire that small to fit 
in your wheel well?

If not, it is more important to have a low rolling resistance tire. This 
depends on the material and construction of the tire, not its width.


Phil Marino

_________________________________________________________________
http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_pcmag_0507


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

Yeah, that article was over the top to be sure. Decades old though? Yikes! Again, one of the 20 year old tires on my Corvair Rampside exploded while sitting in the RV space last week. Those tires were quite new when they were last used. They were not mounted to the vehicle while stored. In fact, they were garaged. A six year old tire is going to be hard and comparatively unsafe. A 20 year old tire is just crazy.

Brian




> ---- Lee Hart <[email protected]> wrote:
> 
> =============
> I can think of endless numbers of cases where people with old or classic cars are running tires that are
> ...


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

That's a good point, Brian. Tires do age, even when not exposed to UV...
such as when stored in a garage, or even on a tire rack. It's one reason
tire stores try to keep their merchandise revolving.

There has been major improvements in tires in the last three decades.
Unfortunately, on low mileage vehicles, the tires can literally "rot" on the
wheel before the tread wears out. It varies, but 6 year old tires should be
considered suspect, and even less if they have been run low and/or repaired.
----- Original Message ----- 
From: "Brian Jackson" <[email protected]>
To: <[email protected]>
Cc: "Lee Hart" <[email protected]>
Sent: Saturday, July 28, 2007 11:09 PM
Subject: Re: Bridgestone Ecopia EP-03 Tires


> Yeah, that article was over the top to be sure. Decades old though? Yikes!
Again, one of the 20 year old tires on my Corvair Rampside exploded while
sitting in the RV space last week. Those tires were quite new when they were
last used. They were not mounted to the vehicle while stored. In fact, they
were garaged. A six year old tire is going to be hard and comparatively
unsafe. A 20 year old tire is just crazy.
>
> Brian
>
>


> > ---- Lee Hart <[email protected]> wrote:
> >
> > =============
> > I can think of endless numbers of cases where people with old or classic
> ...


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

I haven't really examined the tire to see why it failed. The short answer of course is that it is old. Really really old. Twenty years is really stinkin' old man. I mean, this tire was manufactured when Michael J Fox was driving Dr Emmitt Brown's Delorean. That's old! 

These tires were stored in a garage for the better part of 20 years. They were not installed on a car during storage. The car was on blocks out side with no tires under it. These tires were only under a car for about the first two years of their life.

I made sure that they were inflated to the correct pressure. Actually, this increase in pressure may have been partially responsible for the failure. 

Calling an old car dangerous isn't really the same thing. A car is not a wear item. A tire is. I guess if I were operating a large fleet of trucks, then the trucks could be looked at as wear items. In a fleet situation, old machinery could certainly be considered a liability depending on the work being performed. I would not want to be involved in a high speed chase in a 20 year old police car. Ok, I would actually think that was pretty cool, but I'm probably the exception  By contrast, a plumbing contractor would probably have no problem with a 20 year old truck. 

Ralph Nader actually wrote a book about Corvairs being unsafe... and he was right. That doesn't stop me from driving the truck. I like driving old cars. Driving an old car in the same manner as a new one is a recipe for disaster though. Old cars can have poorer brakes, poorer handling characteristics, worn out bushings, old seat belts (yes, seat belts are supposed to be changed from time to time too) or inferrior seat belt design. My Corvair has no seat belts at all. Since it is a truck, it also has no crumple zone. 

What does stop me are the my Corvair are the flexible rubber sections of its 40 year old brake lines. Also, the 20 year old rubber fan belt could go at any time. The fan belt is not fatal, but it is old, it is rubber, and it is on borrowed time.

I understand that a high efficiency tire can be hard to find, but if the only one you can find is too old to be safe then... Improving efficiency at the expense of safety is not a good idea.

=============
Did you examine the tire to see what caused it to fail? Was it 
over-inflated or overloaded? Was there cracking from long-term exposure 
to the sun? Did it fail where the tire had been damaged from a rock or 
curb, or from a previous repair?

I don't doubt that older tires aren't as good or strong as new tires. I 
just wonder if that justifies calling them "very dangerous". Old cars 
are also less safe than new cars; should we label them "very dangerous" 
and order that no car over 6 years old can be driven?

> I have been looking at these tires for my EV project.
> http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Potenza+RE92&vehicleSearch=false&partnum=665SR4RE92&fromCompare1=yes&place=0

Low rolling resistance isn't as important on a Corvair truck, because 
the suspension is not built for it. The rear swing axles have a lot of 
tire scrub, and the front suspension is deliberately setup with toe-in 
to imitate a front-heavy vehicle.

What matters more is the tire's load carrying capacity. This is a truck, 
carrying a heavy load of batteries. The van's GVWR was 4600 lbs. The 
original tires were 7.00x14 bias-ply, rated 1230 lbs at 36psi, 25" 
diameter. The Bridgestone Potenza RE92 165/65SR14 is only rated 937 lbs 
at 44 psi, and is only 22.5" diameter. I think it's too small a tire for 
the application.

If you really like this tire for some reason, try the RE92 175/65R14 XL 
(Extra Load version) for the 2001-2003 Toyota Prius. It is a bit bigger 
in diameter and rated for more weight; 1102 lbs at 50 psi, 23.1" 
diameter (still low, but better).
-- 
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*

I sold my Electravan 750 with the orginal bias tires. They still had good
tread & the sidewalls looked ok. I sent the new owner off to Utah with it
in tow. Of course after 26 years it only had a few thousand miles on the
tires. I wasn't worried one bit. If you are within load ratings tires can
last a long time. Lawrence Rhodes......
----- Original Message ----- 
From: "Brian Jackson" <[email protected]>
To: <[email protected]>
Cc: "Lee Hart" <[email protected]>
Sent: Saturday, July 28, 2007 11:09 PM
Subject: Re: Bridgestone Ecopia EP-03 Tires


> Yeah, that article was over the top to be sure. Decades old though? Yikes!
Again, one of the 20 year old tires on my Corvair Rampside exploded while
sitting in the RV space last week. Those tires were quite new when they were
last used. They were not mounted to the vehicle while stored. In fact, they
were garaged. A six year old tire is going to be hard and comparatively
unsafe. A 20 year old tire is just crazy.
>
> Brian
>
>


> > ---- Lee Hart <[email protected]> wrote:
> >
> > =============
> > I can think of endless numbers of cases where people with old or classic
> ...


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## EVDL List (Jul 27, 2007)

*Re: Bridgestone Ecopia EP-03 Tires*



> Lawrence Rhodes wrote:
> > I sold my Electravan 750 with the orginal bias tires. They still had good
> > tread & the sidewalls looked ok. I sent the new owner off to Utah with it
> > in tow. Of course after 26 years it only had a few thousand miles on the
> ...


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