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

[Edward Mills Antique Tractors <millserat@xxxxxxxxxxxxx>]

Thanks Bill for a realistic (IMO) assessment of the referenced post from 
Old Cars Weekly. I would point out that there are also distinct 
inaccuracies in the referenced post which are frequently repeated 
without checking the facts. And while there may be advantages in putting 
newer wheels on an old car - such as having wheels designed for tubeless 
tire use and wider wheels to support wider cross section, etc., there 
are no such things as different wheels for disc brakes, and to best of 
my knowledge, the term alloy wheels does not apply to the garden variety 
low carbon steel wheels, but rather to the Aluminum Alloy wheels that 
came in during the 60's.

I think the disc brake error comes from disc brakes typically requiring 
larger diameter wheels for clearance, but the Chrysler 15 inch wheels 
for C-body discs beginning in 1966 are the same as those used on 
non-disc cars of same vintage. And the difference on the A-bodies comes 
from a time when drum brake cars still used the smaller bolt pattern 
hubs but the disc cars used the 14 inch wheels with a 4.5 inch pattern.

As to Alloy Wheels, there are definite issues with both Magnesium and 
Aluminum Alloy wheel fatigue in severe applications such as road racing 
- particularly in their early adaptation in the 70's and 80's. Different 
alloys and different heat treats have more or less tendency to fatigue 
but it is important to keep an eye on them for that as well as impact 
damage as they tend to be more brittle than low carbon steel - but I 
have never heard much about fatigue on a steel wheel or on a street 
vehicle in normal useage. Perhaps someone can give us a first hand 
experience??

As to significant wheel design changes, early (pre-1955 or most 
pre-1957) wheels were not designed for tubeless use. They frequently 
resulted in slow leak come-backs as we started to sell more tubeless 
tires. Beginning in 1957 when the 14's came in, the OE tires were 
tubeless only and I believe bead interface was made tighter to improve 
sealing and tolerances were tightened. I can tell you from personal 
experience, the effort to break a 14 inch tire bead to change a tire was 
significantly greater than pre-1957 15 inch tires and from a pure 
geometry and physics (lever calculations), the old style bead breakers 
put more force at smaller diameter.

The next significant changes came when the outer section was welded to 
centers - early designs were typically riveted. I remember seeing a 
Press Release in a search I had done on internet (Kesley Wheels? circa 
1962??) announcing this change had been completed at all their plants.

The next significant change is the only one I know of which is marked or 
coded on wheel markings. From the late 40's thru about 1965/66, wheels 
were designated by a numeric size such as 15x6 (15 inch dia x 6 inches 
inside bead to bead) with a single letter suffix - typically J, K, or L 
in our cases. - the smaller wheels were typically J and the larger 
(wider) wheels for 7.60-15 6 ply and 8.00-15 were typically L. I believe 
the letters were an early load rating system, probably associated with 
thickness of steel and typically the Caddys and big Buicks as well as 
the HP Chryslers typically got heavier wheels as well as wider wheels to 
accommodate the heavier cars and bigger tires - though I can only say 
from memory that as a tire buster, you knew those wheels by weight 
without ever looking for writing on the wheels.

Beginning about 1966, and I think this was to accommodate radials, 
though again, that is more timing coincidence than engineering 
documentation, Chrysler and others (though not all manufacturers and all 
models until about 1969 from checking RMA pubs) changed to wheels with a 
double letter designation typically JJ or JK. I believe the change was 
primarily in the bead interface geometry to provide better bead 
retention to address greater side loads which could be developed with 
the wide ovals and radials. The JJ and JK designations were used well 
into the 70's including OE radials.

Having said all this, my 2 most significant personal concerns with old 
wheels would be condition of wheel (rust, damage, etc) and width 
compared to stated design widths published for the tires you are putting 
on - whether they be radials or wide ovals or just plain old bias tires 
- but then I'm only dealing with mid 60's and newer cars and I'm not 
going to push an antique like I would have when I was young and foolish 
and the 60's cars were new. If you are going with pre-1957 wheels, you 
may want to consider tubes - and if so make sure they are radial type 
tubes.

And lastly watch your inflation, regardless of anything else, this is 
the thing most likely to cause fatal crashes (ref Ford Explorer et al). 
Do not over inflate as it increases load on tires and wheels and has a 
distinct possibility of blowing tire off rim - most older rims were 
designed for about 30-32 psi unless they were designed for the 6 ply 
tires. And Do Not underinflate as it will flex tires and build up heat 
which degrades tires and creates significant pressure loads at temperature.

best to all - Ed

Bill Huff wrote:
>
> 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://hbswk.hbs.edu/item/1832.html>
>
> http://www.classiccar.com/articles/content/index.php?/archives/21-A-Tale-of-Two-Tires.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 bias‑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 
> bias‑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 over‑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 
> <mailto:rpjasin%40pacbell.net>>
> >Date: Wed, 12 Aug 2009 16:00:44 -0700
> >To: Chrysler 300 Club
> ><<mailto:Chrysler300%40yahoogroups.com>Chrysler300@xxxxxxxxxxxxxxx 
> <mailto:Chrysler300%40yahoogroups.com>>
> >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]
> >
> >
>
> [Non-text portions of this message have been removed]
>
> 




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