Buying & mounting new tires tomorrow (two questions)

On Wed, 31 Aug 2011 13:22:01 -0700, jim beam wrote:
> i guess i have to say it again - they're probably mounting in accordance
> with the /real/ dynamic weighting of the wheel that has been /driven/,
> not per the "guess it's balanced" approach you can use with a new wheel.

OK. I get the point that the 'balance' of the 'wheel' (not the new tire)
may not be what it was originally.

But, a new wheel is off by 1.7 minus 0.57 ounces? That's how much a NEW
wheel is off balance, right from the start (according to the reference
PDF).

So, years later, the (now well used) wheel would have to be out of balance
by an additional 1.7 ounces just to negate the whole point of the red dot
(if I understand your premise correctly) before the tire even gets mounted.

Right?


>> Why not just measure the runout of the tire?
>
> why not indeed. but now you've measured it, what are you going to do?
> bend the wheel so the tire's round? at what speed?

Just to be clear. That question of "why not just measure the runout" wasn't
from me. It was a verbatim quote from the PDF that we were pointed to. So
it's not 'my' question. It was just a rhetorical question inside the PDF
since the entire section was quoted by me verbatim.

>> The radial force variation measurement is much more accurate in predicting
>> tire behavior. In fact, the red dot often isn�t located exactly at the
>> �high point.� Instead, it accurately marks where the runout-like force is
>> greatest.
>
> at what speed? harmonics can move that thing around. ask anyone who
> has balanced helicopter rotors.

Again. This was a direct quote inside the article. So, you'd have to ask
'them', not me (as this is well beyond my means to comprehend).

>> The red dot marks the maximum point of radial force variation, and behaves
>> as though it were a �high point� on the tire."
>
> you're giving much too much credence to dumbed down pseudo-tech sales
> crap you read on the net.

Again, just to be clear. You're actually responding to the authors of that
paper. I didn't write it; I just quoted it verbatim.

On 08/31/2011 12:45 PM, SF Man wrote:
> On Wed, 31 Aug 2011 07:35:27 -0700, jim beam wrote:
>> very misleading tire rack rating.
>
> I bought the tires 'by the numbers'.
>
> Tire Rack had about 40 tires that fit.
>
> So I whittled down the list to one tire by assessing:
> * Size = same as original

!!!


> * Traction = AA only (wet)

pointless and misleading exercise. if you read one of my prior posts
and my experience with this "aa" rating, you'll be switched on to the
fact that it may be a flawed rating system.


> * Temperature = A only

how fast do you drive? you know this is a measure of hysteresis
tolerance and nothing to do with external environment don't you?


> * Treadwear = the bigger the better

you know this is directly contradictory to "traction" don't you?


> * Speed = the higher the better

why? what is the top speed of your vehicle?


> * Load range = the higher the better

do you carry heavy loads? a side wall with finer cordage can give a
much more comfortable ride, and hold the tire in better shape than one
with heavy cordage.


> * cost (including tax& shipping& mounting& balancing& disposal)
>
> I 'wish' there was a way to assess dry traction and road noise ... but as
> far as I know, there are no tests that you can find for 40 tires to
> compare.

why would you even try???? people either buy on price, or they buy on
performance. and guess what, there's no "high performance" tire worth a
damn that's cheap. and there's no cheap tire that is "high
performance". decide what end of the spectrum you want, then compare 3
or 4 in that range.


>
> The tire rack reviews seem to all be written by high school dropouts, by
> the way - so,

how can you tell??? is their grammar worse - than, usenet, posters?


> for the final three tires, I did read the reviews, but it was
> a waste of time. They were all good to some degree or another.

translation: "experience doesn't help the indecisive".


--
nomina rutrum rutrum

On Wed, 31 Aug 2011 12:45:19 -0700, SF Man >
wrote:

>On Wed, 31 Aug 2011 07:35:27 -0700, jim beam wrote:
>> very misleading tire rack rating.
>
>I bought the tires 'by the numbers'.
>
>Tire Rack had about 40 tires that fit.
>
>So I whittled down the list to one tire by assessing:
>* Size = same as original
>* Traction = AA only (wet)
>* Temperature = A only
>* Treadwear = the bigger the better
>* Speed = the higher the better
>* Load range = the higher the better
>* cost (including tax & shipping & mounting & balancing & disposal)
>
>I 'wish' there was a way to assess dry traction and road noise ... but as
>far as I know, there are no tests that you can find for 40 tires to
>compare.
>
>The tire rack reviews seem to all be written by high school dropouts, by
>the way - so, for the final three tires, I did read the reviews, but it was
>a waste of time. They were all good to some degree or another.


You plug in your Make/Model to get the tires that fit.
Then start looking at reviews until you find one where the reviewer
is driving your car, or one similar.
Then hit "more tire reviews for this vehicle."
No sense reading a review by somebody driving an Explorer when you're
driving an Accord, even if both are using the same tire.
As I said, I've had good luck picking tires this way.
Some reviews are crap. What's new?
But I've always found thoughtful reviews talking about traction,
cornering, etc.
You can't shotgun it, and it takes some time.

--Vic

On Wed, 31 Aug 2011 13:22:01 -0700, jim beam > wrote:


>
>you're giving much too much credence to dumbed down pseudo-tech sales
>crap you read on the net. take the tires to a shop with a decent
>balance machine like a hunter, and stop second-guessing people like its
>designers who are good at math and have analyzed the problems in
>exhaustive detail.

Yep. For years I've had my new tires Hunter force balanced.
Balanced once. Never needed to be balanced after that.
I didn't pay attention to the dots and neither did the guy who
balanced them.
It's fine to read about the dots. But you learn nothing useful, since
the machine makes all the calls.

--Vic

On 08/31/2011 01:33 PM, Vic Smith wrote:
> On Wed, 31 Aug 2011 12:41:00 -0700, SF >
> wrote:
>
>> On Wed, 31 Aug 2011 08:40:53 -0500, Vic Smith wrote:
>>
>>> forget about the dots. Meaningless when force balanced.
>>
>> Doesn't it allow less weight to be used?
>
> Force balance does that. My kid did this for a couple years at Just
> Tires. The machine determines where to rotate the tire on the rim.
> He said the dots seldom match what the machine says.
> Seldom enough to be random.
>
> --Vic

indeed.


--
nomina rutrum rutrum

On 08/31/2011 01:35 PM, SF Man wrote:
> On Wed, 31 Aug 2011 13:22:01 -0700, jim beam wrote:
>> i guess i have to say it again - they're probably mounting in accordance
>> with the /real/ dynamic weighting of the wheel that has been /driven/,
>> not per the "guess it's balanced" approach you can use with a new wheel.
>
> OK. I get the point that the 'balance' of the 'wheel' (not the new tire)
> may not be what it was originally.
>
> But, a new wheel is off by 1.7 minus 0.57 ounces? That's how much a NEW
> wheel is off balance, right from the start (according to the reference
> PDF).
>
> So, years later, the (now well used) wheel would have to be out of balance
> by an additional 1.7 ounces just to negate the whole point of the red dot
> (if I understand your premise correctly) before the tire even gets mounted.
>
> Right?

that's assuming the weighting is simply tread rubber thickness variance.
it's not.


>
>
>>> Why not just measure the runout of the tire?
>>
>> why not indeed. but now you've measured it, what are you going to do?
>> bend the wheel so the tire's round? at what speed?
>
> Just to be clear. That question of "why not just measure the runout" wasn't
> from me. It was a verbatim quote from the PDF that we were pointed to. So
> it's not 'my' question. It was just a rhetorical question inside the PDF
> since the entire section was quoted by me verbatim.
>
>>> The radial force variation measurement is much more accurate in predicting
>>> tire behavior. In fact, the red dot often isn�t located exactly at the
>>> �high point.� Instead, it accurately marks where the runout-like force is
>>> greatest.
>>
>> at what speed? harmonics can move that thing around. ask anyone who
>> has balanced helicopter rotors.
>
> Again. This was a direct quote inside the article. So, you'd have to ask
> 'them', not me (as this is well beyond my means to comprehend).
>
>>> The red dot marks the maximum point of radial force variation, and behaves
>>> as though it were a �high point� on the tire."
>>
>> you're giving much too much credence to dumbed down pseudo-tech sales
>> crap you read on the net.
>
> Again, just to be clear. You're actually responding to the authors of that
> paper. I didn't write it; I just quoted it verbatim.

so? you didn't quote it and then say you thought it was bunk. you
didn't quote it and ask questions. you quoted it because you agreed
with it and wanted to use it to try to support your argument.


--
nomina rutrum rutrum

On 08/31/2011 01:28 PM, SF Man wrote:
> On Wed, 31 Aug 2011 13:08:01 -0700, jim beam wrote:
>> even if you pay attention to the dots on the tires, it's pointless
>> trying to align them with valves or dots on the wheel unless the wheel
>> is brand new.
>
> Good point.
>
>> do you know more then them? tire shops don't ignore stuff
>> just so you can come back, bitch, and cost them money in warranty work.
>
> I don't know more than they; but I still want my tires mounted properly.
>
> The manufacturer doesn't go to the trouble of putting the dots on the tire
> for no reason at all (do they?).

i can think of two good reasons:

1. they can't be bothered to make decent tires. [3 of the 4 michelins i
have on one car didn't need weights.]

2. it's yet another marketing gimmick. like "synthetic" brake fluid
appeals to people who "want the best". little knowing that /all/ brake
fluid is "synthetic".

now, i'm not dismissing the dots entirely - they would be relevant if
you were trying to do balancing the old fashioned way, putting the wheel
in a stand and waiting for the heavy spot to rotate to the bottom. but
seriously, who does that any more? and even if you have the wheel
balanced for weight, it doesn't mean its round. you can perfectly
balance a square wheel if you want. ever driven a tire that's prone to
flat-spotting after a couple of days stationary?

>
> Unfortunately, after reading the PDF that someone referenced in this
> thread, I now realize the yellow and red dots are vastly more than just a
> 'heavy' spot or a 'light' spot.
>
> For example, witness these quotes:
> "The red dot indicates the �radial force variation first harmonic maximum"
> with the result that "At the red dot location, the tire is trying to pull
> away from the center of the axle a little bit, as a result of higher
> centrifugal force".
>
> So, I printed it out and will bring it to the tire shop because the last
> time I had tires mounted, they told me they never heard of the red dot
> (that was at Goodyear, btw).
>
> I showed it to them on all their tires, and they said they've never noticed
> it before. So, I just wanted to check, ahead of time, where the red dot
> goes.
>
> Thanks to that PDF, I have the answer. It's the right way to balance a tire
> & wheel assembly.

there's /no point/. if the shop has a decent balancing machine, and
they use it per the machine's instructions, neither you nor anyone else
needs to read any pseudo-tech marketing waffle because the machine takes
care of everything.


--
nomina rutrum rutrum

"SF Man" > wrote in message >
> The tire rack reviews seem to all be written by high school dropouts, by
> the way - so, for the final three tires, I did read the reviews, but it
> was
> a waste of time. They were all good to some degree or another.
>

We are told that the customers write these....and your point is well taken.

In any tire series, you will find reviews that hate them and others that
love them. Notice how many miles the tires have
run that are being reviewed.

Look for a trend of opinion. If length of service is important,
keep an eye on the reviews for "typical" service.

Finally, you make a choice and take your chances. Usually you
get good tires.

I recently bought an expensive set of Michelins for my wife's
Avalon from a national tire distribution chain. Drove it out
and suffered on the road with SEVERE shudder. Brought it
back the next day and they cheerfully rebalanced. EVERY tire
was off balance. Lesson...depends upon who does the balancing and the
knowledge and conscientiousness they use.

There are some brands of tires I wouldn't touchif they were free. You can
figure it out by reading reviews at Tirerack,
Discount Tire, or other stores.

On Wed, 31 Aug 2011 14:10:33 -0700, jim beam wrote:

> that's assuming the weighting is simply tread rubber thickness variance.
> it's not.

I'm very sorry. And, I do appreciate your kind explanations. But I'm having
trouble understanding.

The 1.7 ounces minus 0.57 ounces is all of the (aluminum) wheel (it's more
for steel). That calculation has nothing (yet) to do with the tire.

I understood your point that an older wheel 'may' be out of balance but I
don't understand your point above about tread rubber thickness variance
since we're only talking about the wheel at this point.

All I'm asking is 'how much' you think a wheel will be out of balance (in
order to negate the amount known to be out of balance from the start.

Sorry. But, I'm trying to understand you.

On Wed, 31 Aug 2011 14:10:33 -0700, jim beam wrote:

> so? you didn't quote it and then say you thought it was bunk. you
> didn't quote it and ask questions. you quoted it because you agreed
> with it and wanted to use it to try to support your argument.

Huh? I don't understand your response at all.

1. I asked where the red dot goes.
2. Someone pointed to a PDF that explained where the red dot goes (and
why).
3. I quoted that PDF.
4. You asked questions, not believing the text of the PDF.
5. I was just informing you that you were asking questions of that author
of that Bridgestone PDF, and not of me.

So, I can't answer your questions is my only point.

I don't have an argument. I just want to know where the red dot goes.

Sorry if I misunderstood.