Radial Tires on Classic Vehicle Rims

[YellowRose]

Here is something regarding tires and rims that was sent to me by Rob McLellan that many of you will find very interesting to read.

http://files.constantcontact.com/34d...ce88c4b407.pdf

[DKheld]

That is interesting Ray - thanks for posting.

Guess I've been lucky - no problems so far. About 10K and 10 years on the first set of tires but only using 2 OEM Tbird rims on the rear - the other 3 (2 front for disc clearance +spare) were 70's LTD - probably designed for Radials. 2-3K on the second set of tires but this time using all 4 LTD wheels so I can rotate the tires. Only bad part is if the flat is on the front I'll have to move a rear tire to the front and put the OEM spare wheel on the rear. Disc brakes are worth that little bit of trouble though.

Wonder what year the Radial was standard on the Tbird ('64?) and would those wheels fit the Squarebird? Guess Ford went to a 15 inch wheel though so couldn't run the OEM hubcaps - rats. Other newer options that are better I'm sure.

Humm - that brings to mind the Kelsey Hayes Wires - radial design or no? Did the wire design change over the years to accommodate radials?

We sometimes see cracking at the lug on the MG's running radial tires on the OEM rims so it's worth keeping an eye on them.

[jopizz]

Wonder what year the Radial was standard on the Tbird ('64?)

I don't think radials became standard on Thunderbirds until around 1972.

John

[Deanj]

The only problems I had was a Coker tire with a bogus bead. I wondered why the Wheel cover kept coming off. It was the defective bead causing even more flex.

I had a problem with OEM wheels keeping wheel covers on until "tightening" the wheel cover tabs.

Funny how these articles don't provide any proof in the way of statistics. Did I miss how manufacturers changed wheels to comply with radial tires other than making these "stronger"? Let's test that.

Dean

[simplyconnected]

...We sometimes see cracking at the lug on the MG's running radial tires on the OEM rims so it's worth keeping an eye on them.

Oh boy Eric, this got me going.
Tire mass is directly fixed to the road and is unsprung weight. Wheels are bolted to the spindles (also unsprung) before body suspension.

Earlier this year, we saw new wheels that failed with terrible cracks that migrated from the lug holes outward. That cause turned out to be bad bushings and ball joints. Notice, the rear wheels were not affected (in that case).

I have to believe, spindle slop fatigued the steel wheels because radial tires have far less squirm and their sidewalls are stiffer than bias-ply tires. Consequently, radials hold the road better regardless of the boogie-woogie produced by worn steering and suspension.

How about your MGs? Do they have independent suspension? Are wheels failing with radial tires on rear ends or only when used on the front? - Dave

[scumdog]

The only rim failure I’ve had was a front 16” rim on a stock ‘48 F1 pickup.

It was a crack that followed the circumference of the rim, about 5” long.
It was a scary moment as I was entering a curve at the time and it was the outside rim so I ended up on the wrong side of the road.

The reason it happened so suddenly was the wheel had an inner tube which prevented air escaping as soon as the crack started, things didn’t happen until the inner tube blew out through the crack.

I never run inner tubes now!

[DKheld]

Here you go Dave - some rainy day reading

http://mgaguru.com/mgtech/wheels/wl101.htm

Same style suspension as the Tbird - front A-Arm/coil spring and rear leaf although the MG has oil filled lever shocks at both ends and rack and pinion steering.

This particular wheel is on the front (the MG's are half the weight of the Tbird) but its a good pic of a crack. Try finding that on the OEM black Ford wheel - look for a rust line on the black paint would be my thought.



There was even a wheel change mid way through production with a factory service memo saying that they were changed to "improve resistance to crack development".

[OX1]

Article talks about pre-75 wheels?

I personally owned and ran radials on stock rims on;
(I drove these cars from 81 to 87, when I got my first new
car, 86 Capri 5.0)

63 Dodge Polara
65 Galaxy 4 dr
69 Galaxy 2 dr
70 Galaxy 2 dr
72 Monte Carlo

My parents ran radials on stock rims
of both their 60 T-bird (bought new for my mom)
and 65 Ford wagon. In the wagons case, my dad
did not retire it until 1987 (frame rotted almost
clean through), when he got a used 86 ltd (fox body)
rental.

Obviously none of these were today's type perf radials.
Although my buddy from high school, who worked as
a manager @ Goodyear, had a 70 Camaro with Gatorbacks
on what I'm pretty sure were stock type GM rally rims from
well before 75 (this was in 86ish timeframe when gatorbacks
were probably close to the highest perf tire in the world,
when they came out on the 84 vette).

Anyway, something to consider I guess on certain really
old rims, but the construction of the stock squarebird rim
seems more stout than the new rims I bought last year to
fit over disks.

[simplyconnected]

Thanks, Eric. I wondered if any rear wheels failed but the article didn't address that detail.

A couple things come to mind... How come I have never seen a domestic wheel do this? Certainly, we have much heavier cars from that era including muscle cars that produced 4-500 HP (or more). I've seen rear axles twisted and rear end gears blown to **** but wheels survive, even wearing slicks. We also have small cars like the Chevy II, Ford Escort and Fiesta, that use 13" four-lug steel wheels.

Is it the English steel? Is it the wheel design? What is peculiar in these pictures is, the crack looks to me like it starts at the farthest distance (out) from the mounting surface, not at the punched holes or at the welds. The rim looks great.


I would bet that the alloy used in this steel is not correct and prone to metal fatigue. All wheels must flex. If they didn't flex they would simply break from being too hard. Tough steel, like spring steel, is soft enough to cut with a saw but it won't fatigue after many billions of flex cycles. - Dave