Hi Ray -
Reading your post, I think the problem is one of three things:
your tires are bad, your rims are bad, or your tires and rims are
I have heard a lot about Coker Classics. Most of it bad:
Excessive weights needed, premature separation, flat spots. Any of this sound
My advice is to junk the tires and go with American Classics.
Have those on two of my cars. Very happy.
My recently restored 1957 Chrysler 300C convertible has a set of new-ish
wide-whitewall 235/75-15 Coker Classic tires on a set of chrome wire wheels made
by Motor Wheels. The wheels are at least 40 years old, but are still in
excellent condition. However, due to an extended restoration, the
tires are now over 6 years old, but still have the "whiskers", having
accumulated only 500 miles. I had the steering aligned and the
wheels/tires balanced at a very meticulous and cooperative alignment shop using
the Hunter "Road Force" equipment. I was surprised that each wheel
took at least 5 ounces of weights, with one requiring 8 ounces - all over the
inside and outside of the rims! The Hunter equipment showed that
lateral and radial runout of the wheels and tires were within specs, but the
total "roadforce" was above spec on two of the wheel/tire assemblies. The
shop had already tried relocating the tires on the rims, so they said that's the
best they could do; the residual roadforce was because of internal
inconsistencies (stiffness and thickness) within the tire carcass.
The tires seem to flat-spot pretty significantly from sitting in the garage
for a couple of weeks, and even after driving 20 miles at highway speeds, there
is still noticeable wheel vibration. I took the car back to the
alignment/balance shop and they ran it through the full balancing routine again
(not just the plain spin-balancing typical at most tire shops), and their re-run
came up with almost identical numbers. (They very generously only charged
half-price for the re-run!)
This is the first time I've heard of separately balancing the rims alone, and
was surprised that you found that it made a significant difference; I was under
the impression that the combined wheel/tire balancing process took care of any
imbalance of the rims alone. What did your shop do to balance just the
rims alone? It seems like they wouldn't just put knock-on rim weights on
the rim because that would probably interfere with the additional weights when
the tire was installed. Maybe tape-weights on the inside of the rim that
would not interfere with the knock-on weights after tire installation?
Can anyone clarify what I should ask the shop to do to have the rims balanced
separately? Should I have the simulated knock-off hubcaps installed, since
they are actually rather heavy and are somewhat unsymmetrical due the the
knock-off "ears"? Seems like I would have to keep each hubcap dedicated to
a particular wheel, and indexed somehow - maybe paint dots. And even
if that's technically the right thing to do, I'm not sure the wheel mounting
apparatus on the balancing machine could accommodate having the hubcap installed
- as I recall, the wheel is held on with a big spin-on nut with large "ears" of
Ray Melton Las Cruces, New Mexico
Do we have any new updates on the Coker 14" whitewalls that have been
coming along for several years? I have had good results from my last set after
having the rims balanced first. Have to check when back home, but probably
well over 12,000 miles and most at highway speeds up to 95 mph. Usually 75-80
on your nice midwest interstates. I was not happy until Coker suggested
getting the rims balanced. New ballgame after that.
High 80's in Winnipeg area yesterday!
from my iPad
Thanks for your updates on the F tire project.
Have you had a chance to run them at speed. How about the balancing
I just installed American Classics and are happy so far, but have not
got on the freeway yet.