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vic marks

New member
Sep 5, 1999
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Vic there are a couple of problems with your response.

1. "Steel belted tires are the critical issue on GMC's not the load range".
It is ALL STEEL tires that are the issue and they must be load range E. The
side walls must also be steel belted. Be careful you cannot compare load
range D adn E tires.
2. "Is the sidewall the same on a load D and a load E tire?" The sidewalls
are not even the same between load range E tires. You need an all steel
tire which means that the sidewalls are also steel belted.

3. "Is the sidewall belt count an issue at all?" No

4. "Is weight rating really the only critical issue?" No the tire must not
only be capable of supporting 2680# but must be able to handle the sidewall
flexing imposed by the GMC motorhome.

5. "Would a Bridgestone Load D be equivalent to a Michelin Load E?"
Absolutely not. A load range D tire can only be compared to a load range D
tire.

Hope this helps you. I am sending this to you since I do not intend to
post
answers on the net anymore. There are some that like nothing better than
to
argue for the sake of trying to be different.

Tom: I appreciate your response to my query. What I don't understand yet is
this: what is the difference between a load d and load e tire. Load e has a
higher load rating but what gives it that capability? What gives a load E
better sidewall flexing than a load D? And why do different brands of the
the same size, steel belted and similar number of plys have different load
(weight) ratings?

Further to tires, does anybody know of a list on the web of all of steel
belted load E tires on the market suitable for the GMC?

Further, further to tires. I don't know about the rest of you but my
interest in load D vs E has nothing to do with expense. I would like a safe
but comfortable ride. When I was looking to replace my tires, I received
such divergent opinions from Les Caughlin (Load E) and another GMC repair
fellow in the Northwest who did a lot of front end work (he was a load D
guy and was most emphatic about it being a far superior ride) that it has
continued to nag at me. I bought the load E XPS tire but always wondered.
One more thought on this issue: does anybody run larger tires than the
225r16? If so, why and what is the rating?

Vic Marks
Vancouver BC
75 transmode
 
Hi Vic;

I have tried and address your confusion on the tire issues you mentioned

>what is the difference between a load d and load e tire. Load e has a
higher load rating but what gives it that capability?

You can't answer this with one statement. There are a number of ways to do
this, but suffice it to say that by varying the radial ply weave, its fiber
count, denier, by varying rubber compounds, tire construction and by using
different manufacturing techniques (tires are made in different ways) a
manufacturer can design a tire carcass that is strong enough to be labeled
an E load range.

What gives a load E
better sidewall flexing than a load D?
>From my understanding of the discussion and the study that was done, its not
that an E flexs better, its that its stronger. Its that the sidewall of an
"E" is stronger than a load range "D". Strongest of all are "E" load range
tires with a steel fabric radial ply that is the strongest class of tire for
the GM. This allows it to handle the alleged stress the GM puts on its tires
best.

And why do different brands of the
the same size, steel belted and similar number of plys have different load
(weight) ratings?

Vic, ply numbers are not germane and will confuse things. You theoretically
could have a 1 ply tire. Tires differ slightly in their cross section at
various points even for the same size. This accounts for some variance.
More importantly, you have differences in materials, construction type and
manufacturing process that all effect the possible weight ratings. It
sounds to me you are confusing tires that fall in single load range, (ie
"E") that are made differently. If you look at Goodyear for example, they
have 2 market offerings in the E load range. 1) Workhorse, a steel belted
polyester radial ply tire. Its weight rating is 2,700 or so. They also
make the 2) G159 which has a rating of over 3,000 lb.. It has the steel
belts but also has steel radial plys, not polyester. The G159 is the type
of tire Tom W. was recommending and I would too. Steel belted means there is
a reinforcing belt of steel fabric under the tread. It is there to keep the
tread planted flat on the ground. It has no bearing on discussion of the
sidewall radial ply. The radial ply is a layer of reinforcing material
placed in the body of the tire. These plys or layers run from one bead of
the tire to the opposite bead hence the name radial. Steel radial ply is
what we are talking about here as being important. That makes up the
reinforcement of the tire carcass. The 2 (belts and radial plys) are
completely different things.
walter bright 76 GB
 
> Vic, ply numbers are not germane and will confuse things. You
theoretically
> could have a 1 ply tire. Tires differ slightly in their cross section at
> various points even for the same size. This accounts for some variance.
> More importantly, you have differences in materials, construction type and
> manufacturing process that all effect the possible weight ratings. It
> sounds to me you are confusing tires that fall in single load range, (ie
> "E") that are made differently. If you look at Goodyear for example, they
> have 2 market offerings in the E load range. 1) Workhorse, a steel belted
> polyester radial ply tire. Its weight rating is 2,700 or so. They also
> make the 2) G159 which has a rating of over 3,000 lb.. It has the steel
> belts but also has steel radial plys, not polyester. The G159 is the type
> of tire Tom W. was recommending and I would too. Steel belted means there
is
> a reinforcing belt of steel fabric under the tread. It is there to keep
the
> tread planted flat on the ground. It has no bearing on discussion of the
> sidewall radial ply. The radial ply is a layer of reinforcing material
> placed in the body of the tire. These plys or layers run from one bead of
> the tire to the opposite bead hence the name radial. Steel radial ply is
> what we are talking about here as being important. That makes up the
> reinforcement of the tire carcass. The 2 (belts and radial plys) are
> completely different things.
> walter bright 76 GB

That was like a ray of sunshine! Thanks, Walter; lots of valuable
information and insight there.

Could you, or someone else if you don't have the time, expand that into a
"dummies guide to tire/tire construction" kind of article so that maybe we
can all understand the whys of this long running discussion/sometimes
argument? Maybe even some artist types could create some illustrations. I'm
sure that Billy and Patrick and Gene would all be glad to post it on their
websites; it ought to be required reading! I think most agree that tires are
an extremely important factor in safety, but there hasn't been a good
understanding of what all is involved. You could remedy that; you've already
gotten off to a good start with this post.

There might even be the foundation of such an article in existance, probably
from one of the tire manufacturers. If it exists, I'm pretty sure that Billy
can find it!

I'd volunteer but don't have the knowledge; all I know about tires I just
learned from you.

Travis in Lubbock, Texas