Can a tubeless Radial tire work on a 56 F250 stock steel rim?

 

A simple question, that I figured would have received several simple "yes" answers before now. I'll say "maybe". That's because a 1956 F-250 could be fitted with four optional wheels.

The most common is the 16" x 6", Ford 7RD 1015B / K-H 31282. This is a one piece wheel having a standard 5° car or light truck bead profile. It will handle a radial of appropriate width just fine, but you must keep in mind it lacks the inner rim safety bumps of modern rims that help keep a tire on the rim in case of a flat. You probably should seal over the rivets with JB Weld or similar, and use big truck sealing valves.

The second possibility is the 17" x 5.5" Ford 7RY 1007 / Budd 49380. This has the widow maker two piece Firestone RH-5° outer rim. These you should get rid of, and probably would find no shop willing to work on much less agree to mount radials.

Third possibility is the 17.5" x 5.25" tubeless Ford B8D 1015A / Budd 70720 or 73240. These have what are called 15° outer rims, and are specific to truck applications. These will accept 8R17.5" radials just fine, and probably metric sizes that I've not studied up on. More below about radials on 15° rims.

The fourth optional wheel is the 19.5" x 5.25" Ford B6D 1015B / Budd 71410. These tubeless 15° truck wheels will accept 8R19.5" or 225/70R19.5" tires just fine.

Radial tires transmit greater lateral loads to wheels than do bias ply tires. I've tried to find an authoritative source to document their impact on car or light truck 5° type wheels with no success. Stories of cars having their full wheel covers coming free due to wheel flex are out there, but I've found nothing like that with plain hub caps. The story is much clearer on the 15° truck wheels. When radial tires were first introduced in the 1960s the wheel manufacturers began to see wheel failures. They soon published disclaimers in their catalogs stating warranties were voided if radials were mounted. I have a 1970 SAE study documenting the added strain imposed by radials on 15° wheels. Over time the wheel companies redesigned and coded their products that were approved for radials. The light truck single rear wheel style 17.5" and 19.5" wheels never got approved for radials that I've found catalog record of. Of course today radials are the standard and bias ply tires are relics except to purists. In truth, our old trucks today will probably never see the use and abuse that led to wheel failures back in the day. Stu

 

Thank you So much for the great information. My wheel im refering to in my post is of the first style you mentioned.
And it is only one original steel wheel I would be mounting the radial to and that's the spare.
Thank you

 

The bead on a modern radial tire is far less stiff than a bias ply so i would think radials are actually safer. In the 1980s when this question often surfaced people would say that using stock rims would be a deadly thing to do but I've never heard of a problem unless the rims were bad (such as severe rust) When it comes to the wheels, I'm a purist & wouldn't have it any other way. The only exception is on my F250s, the old 16.5s are long gone to the scrapyard in favor of 16s.

 

I realize a different year but ex BIL uses radials on his 1953 3/4 ton stock rims. And it's a daily driver even in NY salt.

 

Probably same 16" wheel mentioned in paragraph two above. Stu