Outside edge of front tires stairstepping

On Thu, 6 Jul 2017 07:15:32 +0000 (UTC), Chaya Eve
> wrote:

>On Thu, 06 Jul 2017 02:08:04 -0400, "Steve W." > wrote:
>
>> What you feel is known as feathering, one side of the tread block wears
>> more than the other. If you looked at the end of the block it would
>> appear as a wedge.
>>
>> It is commonly caused by improper toe settings and if on one edge only
>> by improper camber angle as well. BUT it can also be caused by using a
>> common tire on a vehicle that is driven aggressively. IE high speed
>> cornering. That places a lot of weight on the outer edge of the tire and
>> tries to force it to roll under. That will wear the outer edges rapidly.
>>
>> Now if you had one spot that was "normal" then a wear spot then "normal"
>> going all the way around the tire that would be cupping. That is
>> normally a suspension wear problem.
>
>That was a far better answer than I had expected so I appreciate your
>expertise. The vehicle was aligned but probably about 2 years ago (while
>the tires are about a year old).
>
>The car is driven on a five mile hill every day with scores of hairpins but
>it's NEVER driven fast. Those turns are made probably at 20 to 25 MPH (you
>can't take the turns any faster and stay on your side of the road).
>
>Could that steep (10% or so) continuously twisting 5-miles each way every
>day have caused the "feathering" you explained my "stairstepping" to be?
Run the tires a bit harder - add at least 5 psi and do NOT let the
tires get low on air. DO recheck the alignment as well. A lot cheaper
than new tires.

On Thu, 6 Jul 2017 13:26:35 +0000 (UTC), Chaya Eve
> wrote:

>On Thu, 6 Jul 2017 09:13:13 -0400, Ed Pawlowski > wrote:
>
>> Does not sound normal to me. Could be the toe-in is not adjusted
>> properly. How many miles on the car? Every checked the alignment?
>
>If it were only the tires tilted inward at the front (toe) the whole tread
>would be "feathered" would it not? This only has the outside edge of both
>front tires feathered. So it can't be "just" toe.
>
>I don't see how the miles matter but it has about 60K miles. Miles would
>have nothing to do with this other than suspension wear but nobody is
>suggesting suspension wear based on the evidence (for example, no cupping).
>
>The alignment was last done about two years ago.
>The tires are about a year old.
>
>My take on this is that it's either "normal" for a car that is driven by
>necessity (slowly) on twisty steep (10%) mountain roads for 10 miles (5
>each way) every day, or there is something wrong.
>
>It's not going to be a single thing since the entire width of the tread is
>not feathered (only the outside edges) and since it's both front tires,
>it's not obvious that it's something worn or out of alignment.
You asked for information. It is NOT normal. Get the front end
checked for loose components and alignment, and for running that
downhill chicane every day you DEFINITELY want to slightly overinflate
the front tires. Give me make, model, and tire installed and I'll give
you more ingormation.

On Thu, 6 Jul 2017 16:45:35 +0000 (UTC), Chaya Eve
> wrote:

>On 6 Jul 2017 09:44:30 -0400, Scott Dorsey > wrote:
>
>>>The alignment was last done about two years ago.
>>>The tires are about a year old.
>>
>> Done by an expert at a specialty alignment shop? Done by some bozo at the
>> tire store?
>
>An alignment only shop with something called "Hunger" which was a big red
>machine with a computer screen and mirrors which he drove the car on to do
>the alignment.

That would be a "HUNTER" alighnment machine
>
>> Do you have the paperwork from the last alignment? Did they make dramatic
>> changes to the alignment?
>
>I wish I had saved the papers. It was about 100 dollars with a coupon as I
>recall and it took about a half hour at least, maybe a little bit more but
>they had no other cars waiting as I recall.
>
>I don't remember anything unusual but now I see why I would want to archive
>such things for reference.
>
>> My inclination is to suspect that alignments done by the average tire shop
>> are apt to make things worse rather than better.
>
>I can't imagine that the technician didn't know how to do his job. It was a
>shop where the mother ran the office and he did the work and they were the
>only two people there.

There are alignment guys, and alignment guys. Any alignment guy can
set a car within limits - it takes a GOOD alignment guy who really
understands what is going on to set the alignment perfectly for your
driving conditions. I've known and worked with some of the best in the
business. Iwas pretty good, but didn't do enough to be REALLY good -
unlike my kid brother. He's an opinionated pain in the ass (at least
ten times worse than me -) but there's not anyone I know who will
consistently give you a better alignment. Any I knew who could are
long retired.
>
>>>My take on this is that it's either "normal" for a car that is driven by
>>>necessity (slowly) on twisty steep (10%) mountain roads for 10 miles (5
>>>each way) every day, or there is something wrong.
>>
>> This is true, and one person's "slowly" is another person's "way too fast."
>
>I can hear the tires make noise but never screeching like kids do when they
>put those round black tire circles in the road pavement. Just a
>"scrunching" sound as I go around the turns.

You ARE going "too fast" for the tires and conditions. Again - what
vehicle, and what tire - and WHAT PRESSURE are you running. Placard
pressure for stock tires is about 5psi too low for best cornering wear
on most cars - and for heavy cornering with front wheel drive mabee a
bit more. I generally run8 to 10 psi over placard pressure - and I get
even tire wear and very good tire life.
>
>It's a 2WD Toyota 4Runner if that makes any difference.

What year?? What tires do you have on it? Bridgestone Geolanders? or?

Are they 265-65s? a 245-70 will be about the same hight and won't give
as much treadwear problems on the corners.
>
>I don't think I can take the turns much slower than about 20mph as I'm
>always the one who pulls over to let others pass me on that road.
>
>I just want to know if the road curves are the problem, why the rear tires
>don't show the same outside feathering that the fronts show at 4K miles.
>
>> However, I might consider investing in higher performance tires next time
>> when these wear out. They may or may not last longer, but they will sure
>> make driving those twisty roads more enjoyable and more safe too.
>
>The tires are TREADWEAR = 380 if that's what you mean by "performance".
"performance" tires on that machine for your driving would be a
TOTAL waste of money - and generally yhey wear a whole lot faster.

Chaya Eve > wrote:
>An alignment only shop with something called "Hunger" which was a big red
>machine with a computer screen and mirrors which he drove the car on to do
>the alignment.

Equipment doesn't matter so much, what matters is the guy who did the job.
But you don't throw up any red signs here.

>I can hear the tires make noise but never screeching like kids do when they
>put those round black tire circles in the road pavement. Just a
>"scrunching" sound as I go around the turns.
>
>It's a 2WD Toyota 4Runner if that makes any difference.
>
>I don't think I can take the turns much slower than about 20mph as I'm
>always the one who pulls over to let others pass me on that road.
>
>I just want to know if the road curves are the problem, why the rear tires
>don't show the same outside feathering that the fronts show at 4K miles.

I don't know, but the forces on the front and the back are very different,
in part because of steering and in part because side-forces are very
different.

>> However, I might consider investing in higher performance tires next time
>> when these wear out. They may or may not last longer, but they will sure
>> make driving those twisty roads more enjoyable and more safe too.
>
>The tires are TREADWEAR = 380 if that's what you mean by "performance".

I'd be more interested in the speed rating. The UT treadwear rating of
380 isn't terribly high but isn't terribly low either.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On Thursday, July 6, 2017 at 6:45:49 AM UTC-10, Chaya Eve wrote:
> On Thu, 6 Jul 2017 23:40:10 +1000, Xeno > wrote:
>
> > That means you *are* traveling very fast, at least for the conditions.
> > What you are saying is that you are leaving no safety margin on each
> > hairpin. You will definitely be wearing the outer edges of the tyres
> > doing that.
>
> Well, sometimes I can hear the tires scrape on the turns as I'm going so
> slowly (about 20 to 25mph) but I'm also heading downhill (or uphill) at a
> steep (I'm told it's consistently 10%) angle.
>
> I never heard of angles in percentages but when I looked that up it seems
> to be the way they do roads.
>
> The hilly curves might be the problem, in which case an alignment is a
> waste of money (I don't have a lot of money to eat up tires or to do
> superfluous alignments either).
>
> Would the fact that the rear tires are not affected mean anything if I was
> trying to figure out if the curves were the problem?
>
> >> Could that steep (10% or so) continuously twisting 5-miles each way every
> >> day have caused the "feathering" you explained my "stairstepping" to be?
> >>
> > The hairpins are the reason for the feathering on the outer edges of the
> > tread.
>
> On the five mile drive, there are about five hairpins where you literally
> end up going the opposite way you started (180 degrees). Generally you can
> take the hairpins wide on the outside direction but you have to take them
> narrow on inside part of the curve because you can't see around them.
>
> The rest of the many curves are 90 degree curves. There aren't many less
> than 90 degrees.
>
> The main question now that I know it can either be the curves or the
> alignment (too much toe in at the front of the front tires plus too much
> camber in at the top), I wonder if the fact the rear tires are fine tells
> you anything.
>
> On a curvy hilly road, if the fronts were feathered from the curves, would
> the rears still be even?
>
> >If you adjust to eliminate the feathering on curves, you may see
> > wear on the inside of the tread instead. It is a suspension geometry
> > anomaly, a compromise if you will, that you can do little about. If you
> > only drove on a freeway every day, you would see no feathering.
>
> This is what I'm wondering, which means there is nothing I can do to
> compensate other than maybe tire pressure and wheel rotation.
>
> Frequent rotation would be obviously a given, but I noticed that a cross
> rotation (which is what they did) without the spare (the spare is a
> different width tire for some reason) still puts the feathered edge on the
> outside when the fronts were put on the rear.
>
> Would you add MORE or LESS air to prevent the front tires feathering if
> it's the curves doing the feathering?
>
> And would you have the tires mounted the other way every few rotations?
> (The problem with that is the inside is a whitewall so they'd all have to
> be remounted and not just the two feathered ones.)
>
>
> > FWD
> > vehicles tend to fare worse for a number of reasons, one being the
> > greater SAI angles generally used on them, another being the greater
> > weight on the steering axles.
>
> It's a Toyota 2WD 4Runner.
>
> > I get the same issue here with my Toyota
> > due to the predominance of roundabouts and sharp corners I need to
> > negotiate. The steering alignment was, and is, spot on.
> >
> > Toe specs are usually given as a range. Set yours to the favourable side
> > of the spec range realising that FWD vehicles tend to be positive toe
> > rather than negative.
>
> I'm thinking of this as a plan so how does it sound?
>
> 1. First I need to figure out if it's just the curves or if it could be the
> alignment so that's why I ask most of my questions, particularly why the
> rears are perfect while it's only the fronts that have the outside edge
> feathering the same on both tires.
>
> 2. If it's alignment, then the answer is to pay the hundred bucks to have
> it aligned and that's all that can be done.
>
> 3. However, if it's the curves, then an alignment is a waste of money
> better spent on food or tire rotations (which I get free at Costco).
>
> 4. What I can do is just get rotations every three to six months which is
> never a bad thing anyway (it just takes time, mostly waiting in line).
>
> 5. Since the tread is not directional and since the last rotation still put
> the feathered outside edge of the front tires on the rear in the same
> orientation, what do you think about having all four tires remounted the
> other way on every second rotation?
>
> They have to be done all four because they're whitewall on one side only
> and blackwall on the other side only.
>
> Does that sound like a good plan?

It doesn't sound like much of a plan. Just have the toe-in adjusted. You'll probably have to compensate for your worn-out, loosey-goosey, suspension. Then forget about it. This ain't rocket science. Forget about camber too. You can't adjust it.

On 7/07/2017 2:45 AM, Chaya Eve wrote:
> On Thu, 6 Jul 2017 23:55:24 +1000, Xeno > wrote:
>
>> Camber does not cause feathering. It does cause wear on one side.
>
> I think the advice so far is good in that it's either of these two:
> 1. Too much camber (top spread out) + too much toe (front spread in)
> 2. Hills with curves
>
> If it's the alignment (camber plus toe) it can only be fixed with an
> alignment. If it's the hills with curves, there's nothing to fix.
>
> The fact that the rear tires have no obvious strange wear might be a clue
> to help. Would the hills with curves also affect the rear?

Short answer, no. Totally different suspension. The front is lateral arm.
>
> Or do hills with curves only affect the front feathering?

The front wheels are the steering wheels. They have the appropriate
geometry, the rears do not.
>
>>> The tires are "feathered" only on the outside edge of the tread (last inch
>>> or two) evenly on both tires, but only on the front.
>>>
>> The greatest cause of outside edge tyre wear is overenthusiastic cornering.
>
> I don't enthusiastically corner. Period. I drive slowly.
> But I can't change the five miles each way that are hills with sharp curves
> where most are hairpins and there is no stripe in the road since it's too
> narrow for a center stripe.
>
> I'm guessing the speeds are 20mps or so but the turns are extreme.
>
> Would that only affect the front feathering leaving the rear unfeathered?
> It's a rear drive 2WD basic SUV with a solid rear axle I am told.
>
>> One point I should note. By all means have your alignment checked. One
>> thing that can cause feathering is a bent steering arm. Typically, a
>> bent steering arm will cause a change in toe. If the technician just
>> corrected the toe, he will have missed the real issue and the car will
>> now have incorrect *toe out on turns*. A *toe out on turns check* should
>> always be done at a wheel alignment as it will show up issues like bent
>> steering arms.
>
> Anything can happen at a pothole or curb but I seriously doubt anything
> major is "bent" since I'm the only driver and it was thoroughly checked two
> years ago when I bought it, including a full four wheel alignment.
>
> My main question is how to determine if the front feathering is only due to
> the 90 and 180 degree corners on a 10% grade (I'm told) I have to go
> through at 20 mph every day (at least twenty of them each way).
>
> Would that type of hilly curve NOT affect the rear tires at all?
>
You have a solid live rear axle in that vehicle. There is no possibility
of a camber or toe adjustment at the rear. There is no change in camber
due to suspension deflections.

--

Xeno

On 7/07/2017 2:45 AM, Chaya Eve wrote:
> On Thu, 6 Jul 2017 23:40:10 +1000, Xeno > wrote:
>
>> That means you *are* traveling very fast, at least for the conditions.
>> What you are saying is that you are leaving no safety margin on each
>> hairpin. You will definitely be wearing the outer edges of the tyres
>> doing that.
>
> Well, sometimes I can hear the tires scrape on the turns as I'm going so
> slowly (about 20 to 25mph) but I'm also heading downhill (or uphill) at a
> steep (I'm told it's consistently 10%) angle.
>
> I never heard of angles in percentages but when I looked that up it seems
> to be the way they do roads.
>
> The hilly curves might be the problem, in which case an alignment is a
> waste of money (I don't have a lot of money to eat up tires or to do
> superfluous alignments either).
>
> Would the fact that the rear tires are not affected mean anything if I was
> trying to figure out if the curves were the problem?
>
>>> Could that steep (10% or so) continuously twisting 5-miles each way every
>>> day have caused the "feathering" you explained my "stairstepping" to be?
>>>
>> The hairpins are the reason for the feathering on the outer edges of the
>> tread.
>
> On the five mile drive, there are about five hairpins where you literally
> end up going the opposite way you started (180 degrees). Generally you can
> take the hairpins wide on the outside direction but you have to take them
> narrow on inside part of the curve because you can't see around them.
>
> The rest of the many curves are 90 degree curves. There aren't many less
> than 90 degrees.
>
> The main question now that I know it can either be the curves or the
> alignment (too much toe in at the front of the front tires plus too much
> camber in at the top), I wonder if the fact the rear tires are fine tells
> you anything.
>
> On a curvy hilly road, if the fronts were feathered from the curves, would
> the rears still be even?
>
>> If you adjust to eliminate the feathering on curves, you may see
>> wear on the inside of the tread instead. It is a suspension geometry
>> anomaly, a compromise if you will, that you can do little about. If you
>> only drove on a freeway every day, you would see no feathering.
>
> This is what I'm wondering, which means there is nothing I can do to
> compensate other than maybe tire pressure and wheel rotation.
>
> Frequent rotation would be obviously a given, but I noticed that a cross
> rotation (which is what they did) without the spare (the spare is a
> different width tire for some reason) still puts the feathered edge on the
> outside when the fronts were put on the rear.
>
> Would you add MORE or LESS air to prevent the front tires feathering if
> it's the curves doing the feathering?
>
> And would you have the tires mounted the other way every few rotations?
> (The problem with that is the inside is a whitewall so they'd all have to
> be remounted and not just the two feathered ones.)
>
>
>> FWD
>> vehicles tend to fare worse for a number of reasons, one being the
>> greater SAI angles generally used on them, another being the greater
>> weight on the steering axles.
>
> It's a Toyota 2WD 4Runner.
>
>> I get the same issue here with my Toyota
>> due to the predominance of roundabouts and sharp corners I need to
>> negotiate. The steering alignment was, and is, spot on.
>>
>> Toe specs are usually given as a range. Set yours to the favourable side
>> of the spec range realising that FWD vehicles tend to be positive toe
>> rather than negative.
>
> I'm thinking of this as a plan so how does it sound?
>
> 1. First I need to figure out if it's just the curves or if it could be the
> alignment so that's why I ask most of my questions, particularly why the
> rears are perfect while it's only the fronts that have the outside edge
> feathering the same on both tires.
>
> 2. If it's alignment, then the answer is to pay the hundred bucks to have
> it aligned and that's all that can be done.

Call the hundred bucks *insurance*.
A wheel alignment will ensure you get the best life from your tyres.
>
> 3. However, if it's the curves, then an alignment is a waste of money
> better spent on food or tire rotations (which I get free at Costco).

You should be buying food and rotating tyres as a natural response to
life in general. Both are necessary.
>
> 4. What I can do is just get rotations every three to six months which is
> never a bad thing anyway (it just takes time, mostly waiting in line).
>
> 5. Since the tread is not directional and since the last rotation still put
> the feathered outside edge of the front tires on the rear in the same
> orientation, what do you think about having all four tires remounted the
> other way on every second rotation?

If your spare is the same as the 4 on the vehicle, do a 5 wheel
rotation. Best look at the owners manual to see how Toyota see rotation
best carried out.
>
> They have to be done all four because they're whitewall on one side only
> and blackwall on the other side only.
>
> Does that sound like a good plan?
>
I have an issue with point one, first sentence. How can you figure out
if it's an alignment issue *without doing an alignment*? This is very
much the case since you cannot see why the rears will not have the
issue. Since you lack an understanding of steering and suspension
geometry, you will need to rely on the expertise of others. As I said,
do an alignment check ensuring that toe out on turns is also checked.
That will ensure that your steering arms are not bent. If you purchased
the vehicle second hand, you have absolutely no idea how it had been
driven in its past life. A toe in adjustment can cover up a bent
steering arm but the effect will be similar to incorrect toe and will be
exacerbated if you are doing extreme cornering. With steering, you
*must* start from a known position. If you cannot recall what was done
in your last wheel alignment, you might benefit from another one right
now. That way you can get Factory specs, what spec your car currently is
and what it has been set to. That should be on the wheel alignment sheet
you get as a customer and if you don't get it, ask for it.



--

Xeno

On Fri, 7 Jul 2017 14:45:16 +1000, Xeno >
wrote:

>You should be buying food and rotating tyres as a natural response to
>life in general. Both are necessary.

Not everyone recommends rotation. It's not even possible on some
vehicles. Just replace them in pairs as they wear out. I've personally
never rotated my tires on any car, but that's admittedly just my
choice. In fact, on the car we're talking about, the feathered tires
are probably noisy anyway, so she'd just be moving the noise to the
back, where it might be even worse.

On 07/06/2017 10:45 AM, Chaya Eve wrote:
> I just want to know if the road curves are the problem, why the rear tires
> don't show the same outside feathering that the fronts show at 4K miles.
>

afaik, the 4Runner does not have independent rear suspension. To
simplify, the rear wheels will be perpendicular to the pavement while
the front tire geometry will vary.

Long shot, but what sort of tire? I had a Michelin Anakee 2 front tire
on one of my bikes that had a very strange wear pattern. Everyone who
ran that tire saw the same thing and Michelin went to the Anakee 3 to
correct the issue. Whether it was the tread block design or something
else it developed a similar pattern to what you are describing except
being a bike it was on both sides. It neither impaired the ride or
handling, it just looked weird.

On Thu, 6 Jul 2017 22:58:43 -0600, rbowman > wrote:

>On 07/06/2017 10:45 AM, Chaya Eve wrote:
>> I just want to know if the road curves are the problem, why the rear tires
>> don't show the same outside feathering that the fronts show at 4K miles.
>>
>
>afaik, the 4Runner does not have independent rear suspension. To
>simplify, the rear wheels will be perpendicular to the pavement while
>the front tire geometry will vary.
>
>Long shot, but what sort of tire? I had a Michelin Anakee 2 front tire
>on one of my bikes that had a very strange wear pattern. Everyone who
>ran that tire saw the same thing and Michelin went to the Anakee 3 to
>correct the issue. Whether it was the tread block design or something
>else it developed a similar pattern to what you are describing except
>being a bike it was on both sides. It neither impaired the ride or
>handling, it just looked weird.

In conversations about this with GM engineers, they did mention
problems with certain tires, and with certain vehicles.

Anyway, nearly everyone agrees the alignment should be checked. It's a
basic first step - as long as it includes a full check of all the
steering and suspension - and really should be done. But if the
alignment is right on, then it's time to Google that vehicle and those
tires to see if there is a common issue.