[FWDLK] Radial vs Bias Plys-56 vs 41 Plymouth

["Lars Larson 56 Plymouth" <LARSPAINTR@xxxxxxx>]

Decided to get the 6:-00/16 BFG wide whites on the 41 Ply 2dr cut (siped) at
discount tire to try to get better traction in the wet and minimize squeal on
even slow turns.  All they had was the 4 or 5 longitudinal grooves with no
tread blocks-   OLD original tread pattern.  They run and drive fine up to the
57mph  or so I have had it up to.  And comfortable enough.
So for the >>>>LOOK folks, I put my 56 Ply wagons Stones on the 41- they are
Firestone 480 P205/75/15 bw radials on the wagons 6" (I think) rims.  Rims
interchanged perfectly.
Results-
Tracking (the property of the car moving or turning in the direction the
steering wheel is turned, be it in a corner or straight)-  Improved.  It
tracked well enough before but was very sensitive to tire grooves made by
trucks at stops and on 2 laners, you had to drive the up side of the groove.
It does not steer itself now but is much more comfortable.
Steering effort (how much strength it takes to turn wheel for wheel movement)-
at rest or close to it- bad.  Car MUST be moving to turn wheel at all.  Once
its underway the effort becomes same as for bias plys by 20 mph.
Ride comfort (general)-  No change for undulating pavement- shock control
governs here and ride is same.  Worse on transverse tar strips, expansion
joints, and even small spalls in pavement, also pavement that may be
resurfaced with larger aggregate or having a series of small ridges.
Excellent at 55 mph though.  Effect of 2 laner grooves becomes close to nil.
Bottom line- bias plys win in town, radials on cruises.
Appearance- you decide.
I did not go to the efort to put the 41 wheels/bias plys on the 56- too
())(*(()@#@# much work.  Also the wagon has  HD springs front and rear and gas
charged modern shox and the 41 has  true Oriflow shox, OE style non- gas
charged and are ready to be replaced -- but old Pre '50 Moparz tended to ride
mushy anyhow...
  The results compare with my friends 56 Ply 4 dr post sedan that he put
radials on, I drove it and was suprised that, without the HD springs, it too
had that hard feel to road strips and holes- really telegraphed the jolts to
the steering wheel and to the driver.  Note that as a passenger that same feel
is almost non existant, even in my wagon with the HD springs.
  I have heard and more or less bought into the argument of 'new' bias plys,
that they  are superior to what was used 40 or 50 years ago due to improved
materials and technology.  Well with almost 12 ounces (yep) of weight on the
worse wheel of the 41, and 5.5 on the best, I really wonder.  I cant remember
EVER having that kind of weight on the old bias ply or bias belted tires, more
like 7 possibly 8 oz max.  Currently I am not overimpressed with these new old
tires, though they do go round and round and I can drive 55 just fine- but I
could 40 or more years ago too.
How well did the sipes work?   Gotta wait for some rain for that.
But for daily useand after driving in the 41 on familiar roads,  I'll take the
bias plys
for it!!!! Too much feel of road irregularities, too hard steering.   If I
wanted to cruise at 70 effortlessly I would drive the 56 wagon with V8 and
overdrive.
history
I had owned new a 60 Valiant, 62 Savoy post with 318 stick, 66 Cuda V8 Auto
and all had bias plys.  The Savoy was driven to Florida at least once.  The
Cuda also.
Interstates were new then, no problems at speed.  My guess is that if U have a
57 or newer Mopar, esp a larger heavier vehicle, the ride situation would be
hard to notice with radials, and think many of U have posted so.
Hope some of this can be useful  to someone wanting to make the change.  But
watch that rim width!!!!  No radials on 4.5" skinnly wheels unless U buy big
buck Michelin X non metric tires.
L.

Finally -- a formula for those interested in mph vs tire size vs gear
ratios----

             (RPM) ( Tire Dia inches) ( .003)
Mph =  ---------------------------------------------
                      Overall gear ratio

of course U can solve for RPM or for tire dia by simply transposing.

Example-  using a 3.54 final drive and 6:00 x 16 tires (static loaded radius
14")
            and 3000 rpm, the car speed would be 70.5 mph.  This is fine in
theory
            but the car comes with a 4.3 ratio as stock.....
U can check speeds in lower gears but must multiply transmission ratio by the
rear axle ratio.  Note the fine print, it said static loaded radius, not just
an assumed  radius.

PS-  after a light cold rain, took the 41 out with the siped tires.  Little if
no aparent change!  Still loud squeal on semi panic stop.  Still similar noise
on rounding corners too energetically.  Ah me.  But wasnt it that way years
ago too?  Stock is still stock....