Re: [Chrysler300] Radial Tires on Original Bias Ply Wheels

[Bill Huff <czbill@xxxxxxxxxx>]

Tony,

Thanks, that was interesting, I recall when it 
was last posted.  Unfortunately, it is really 
anecdotal,even the part by the accident 
investigator.  It seems to me that in order to 
make a judgement on the degree of danger in using 
rims designed when bias tires were the norm 
mounted with radial tires, more information is needed.

IMHO we need either engineering studies showing 
the relative strengths and resistance to flex of 
the two types of rims, and/or a large sampling of 
numbers of bias rims using radial tires vs numbers of rim failures.

The accident investigator probably has not 
investigated many of the types of accidents where 
old rims fail due to radial tires simply because 
their probably have not been many such accidents 
to investigate.  Certainly most folks didn't keep 
their old cars long enough to be using radials on 
the older rims, bias ply tires were available for 
many years after radials became the OEM 
tire.  Non-enthusiasts probably change cars every 
5-10 years, don't have those stats and too lazy 
to look them up.  Point is, if radials were on 
new cars in 1972-1973 for instance, by 1980, the 
large majority of people were probably driving cars that came with radials.

Apparently radials became commonly available in 
the US in 1966 or so from after market 
sources.  If they were causing rim failures, they 
probably would have soon withered away.  Accident 
investigation was not what it is today, so we 
probably will never know for certain how many 
failures may have occurred in the early years of radials.

http://hbswk.hbs.edu/item/1832.html

http://www.classiccar.com/articles/content/index.php?/archives/21-A-Tale-of-Two-Tires.html

So, I think we have poor or no reliable 
statistics on this issue in the 60's and into the 
late 70's.  By the early 80's I believe few 
people, other than those who could not afford 
newer cars, or old car nuts were driving those 
pre-radial cars.  The poorer folks probably did 
not equip their cars with more the newer, more 
expensive radials when tire replacement was at 
hand.  I think it is safe to assume that the pool 
of vehicles using bias ply rims with radial tires 
has been small since the 80s and has gotten quite 
small into the 90's and on.  Although we have no 
real figures to go on, I think that the old car 
community is a close knit gene pool with many of 
us having more interests than 300s, I myself am 
on several message boards and have never actually 
heard of a rim failure attributed solely to using 
radial tires.  I am afraid I have been using them 
myself for 25-30 years without problems.  Does 
this prove anything?  Not in and of itself, but 
if no one is really reporting a problem, and 
between us all we are exposed to a significant 
percentage of the old car community, that is a telling fact.

Finally, for anyone who managed to get this far 
without falling asleep, I believe that any 
changes in rims were driven by vehicles 
increasing in HP and weight rather than tire 
type.  For the life of me, I cannot fathom how a 
more flexible tire, which the radial is, can 
cause more flex in the rim.  Seems like a stiffer 
tire would do that?  For the road, I still 
wouldn't hesitate to continue using radials on my 
old cars.  If I decide to go canyon carving or 
road racing, I will most certainly buy new, larger rims for that purpose.

Ok, rant off.  I do appreciate the efforts to 
educate us to possible danger, I just don't quite 
know if the information is factual in the sense 
that all other variables have been eliminated and 
a percentage of chance of failure 
assigned.  After all, any tire, any rim, may fail 
at any time without prior notice.  It is 
dissecting the failure and coming to a good conclusion that is missing here.

Regards,

Bill Huff


At 8/15/200910:19 AM, Tony Rinaldi wrote:
>
>
>Hi to all,
>
>As promised, I am attaching the text from an article in Old Cars Weekly.
>Please do not kill the messenger!
>
>Tony Rinaldi
>
>__________________________________________________________
>
>The following is reprinted from Old Cars Weekly from Sept 21, 2006 and warns
>of the danger of wheel failure unless the rims are replaced by stronger ones
>designed for use with radial tires.
>__________________________________________________________
>
>Q. Recently, I purchased five new wide whitewall radials from a reputable
>tire company (one of your advertisers). The car for their intended use is a
>1956 Mercury that previously had biasâ??ply tires. Although I had the new
>radials professionally mounted and balanced, the front hubcaps come off
>while driving, especially the left front on right turns. Can you advise me
>if I need to replace the wheel rims with a heavier type? Robert W. Blume,
>Sr., Calverton, N.Y.
>
>A. Back in 2003, we had a lively discussion of wheels intended for biasâ??ply
>tires "throwing" hubcaps when mounted with radials. Here are readers'
>comments from that discussion. "The problem of cars 'throwing hubcaps' is
>much more serious than rim flex and lost hubcaps. Try losing your life with
>this problem! Rims for bias-ply tires, radial-ply tires, even disc brake
>rims are made out of different alloys. Rims for bias-ply tires cannot use
>radials, and bias and simple radial-ply rims cannot be used for disc brakes..
>The forces exerted by bias-ply versus radial-ply tires (as well as disc
>brakes) are different and need rims made specific to each application. When
>using radial tires on bias-ply rims, the rims overâ??flex as they are unable
>to handle the forces of the radial tires. This over-flexing also means metal
>fatigue, breakage (most commonly rim bead edge separation), and deadly
>accidents. Many will disagree, touting their successful usage of radial
>tires on bias-ply rims, but as a fatal accident investigator, the first
>place I looked in any older car accident was at the rims. My advice when
>replacing bias tires with radials is to immediately change the rims. One can
>tell bias, radial, and disc brake rims by their markings," wrote Sam Egan,
>general manager, Automotive Information Clearinghouse, La Mesa, Calif.
>Another reader wrote, "When you install a radial tire on an old rim and the
>footprint of the tire is wider or equal to the rim bead, the twisting of the
>sidewall puts undue stress on the lighter and original rim. We put radial
>tires on our 1956 Ford and had the same problem. We cured the problem when
>we switched to 1966 Ford rims, which are one inch wider and eight to nine
>pounds heavier, which makes them stronger than the old rims." Paul Haase of
>Waterloo, Iowa, also advised replacing the rims. "Then if the wheel discs
>still slip, they can be held in place a bead of silicone." Sanford Danziger
>recommended locating a set of alloy rims, which would obviate the hubcap
>problem. To hold the wheel covers in place, assuming movement is still a
>problem with the correct rims, Dan Reed says he secured the wheel covers for
>his 1956 Cadillac with a strap that was secured by one of the lugnuts. He
>found this idea on a 1958 Oldsmobile. The strap has to be long enough to
>allow access to the lug nuts. "It won't prevent the wheel cover from coming
>off, but will keep it from being lost," he wrote. Marilyn Robinson ended the
>problem of wheel covers flying off their Plymouth Valiant by switching to
>hubcaps. Terry Wallace of Pensacola, Fla., brushed some of the grit coating
>used on surf and skateboards onto the rim area that the wheel covers
>contact. The covers still wanted to walk on the rim, so he added a bead of
>silicone and has had no further trouble. Bob Brooks of Suffield, Conn.,
>coated the wheel rim contact area on his 1952 Mercury with rubber cement and
>hasn't thrown a wheel cover since. To hold the full disc, wheel covers on
>his 1989 Thunderbird, Lou Frueh of Wickliffe, Ky., drilled a hole in the
>wheel cover 180 degrees from the valve stem, then drilled and tapped a hole
>in the wheel as near the rim as possible, and bolted on the wheel covers. He
>disguised the bolt to look like another valve stem. Thomas Murray of San
>Leandro, Calif., found that a strip of masking tape around the rim holds the
>wheel covers on his two Kaisers in place. Bob Lewis of Susanville, Calif.,
>uses silicone adhesive sealant to keep the full disc wheel covers on his
>1950 Ford club coupe from moving. Gerald White of Altoona, Fla., observed
>that the brake drum will keep the center of the wheel from flexing, but not
>the rim, leading us back to Mr. Egan's warning about the danger of wheel
>failure unless the rims are replaced by stronger ones designed for use with
>radial tires.
>
>From: Bob Jasinski <<mailto:rpjasin%40pacbell.net>rpjasin@xxxxxxxxxxx>
>Date: Wed, 12 Aug 2009 16:00:44 -0700
>To: Chrysler 300 Club 
><<mailto:Chrysler300%40yahoogroups.com>Chrysler300@xxxxxxxxxxxxxxx>
>Subject: [Chrysler300] Radial tires on Beautiful Brutes
>
>Tony,
>
>I took the subject as being all of our letter cars running radials. Having
>said that, if you do have the information from the accident investigator and
>it would be easy for you to email it, I would like to see the data. I do
>forklift accident investigation work and I actually like reading reports
>like you describe.
>
>Thanks!
>
>Bob J
>
>[Non-text portions of this message have been removed]
>
>


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