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