Tiny - the organization linked is the Tire and Rim Association, the group that sets the standards that the US govt refers to in setting it's rules ... having checked the govt regs, no mention is made of rim type other than reference to the "dimensions", and every other discussion I've seen refers to the width of the rim being appropriate for the tire size

note here where the TRA standards are discussed, there's no mention of alloys or age of rims, but a lot about width and aspect ratio

the TRA charges $80 for the full book on the subject, but according to the reg you should be able to see a list of "approved" rims at any tire dealer!!!

find the relevent following govt requirements here
"S4. Tire and rim matching information.
S4.1. Each manufacturer of tires must ensure that a listing of the rims that may be used with each tire that it produces is provided to the public in accordance with S4.1.1 and S4.1.2.
S4.1.1 Each rim listing for a tire must include dimensional specifications and a diagram of the rim and must be in one of the
following forms:
(a) Listed by manufacturer name or brand name in a document furnished to dealers of the manufacturer's tires, to any person upon request, and in duplicate to: Docket Section, National Highway Traffic Safety Administration, 400 Seventh Street, SW., Washington, DC 20590; [.....] "

no the the Business Week discussion doesn't address cracking, but it seems to discredit it when it states:
"MYTH AND FACT. The supposed hazards of using radial tires on vehicles that were originally equipped with bias-ply tires are some of the hardest myths to dispel, partly because, as in most myths, some truths can be found. For instance, it's true that many older vehicles were not engineered to take advantage of radial tire designs. But that does not make using radial tires on older vehicles unsafe or a waste of money.
When combing through the myths to get to the facts, four areas emerge. Three deal with physical characteristics: tire size, contact area, and tire weight. The fourth deals with load-carrying capabilities, and is the concern of least importance.
"

how about if the cracking isn't a result of the tire type, but because of an inappropriate size? or even just metal fatigue due to age and abuse?

and I noted that Coker seems to think using radials is a cosmetic question

I've been using radials since the 70s and have never had a vehicle newer than 67 - I've worn out sets of radials on old rims, city and highway driving - never had a rim crack

Bill



Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics