Packard Forum Index » Post-War (1946-54)

Last week I replaced the 20+ year-old bias ply tires that came with my '50 Custom with WWW radials from Diamond Back. The old tires looked like new with no discernible tread wear but they had the skinny whitewall and I wanted something closer to the original whitewall. Also, just knowing how old the tires really were made me nervous. I read several threads here and elsewhere debating the wisdom of installing radials on older cars and based on reports of improved handling decided to go with radials.

Prior to the installation of radials, driving the '50 was a bit of a chore, I tended to keep a death-grip on the steering wheel in anticipation of the next pull to the left or the right, depending on the road surface. The car tended to 'wallow' around corners.

The difference in handling is far greater than I had anticipated. The car no longer goes off on its own, following every little flaw in the road surface, steering is easier, more responsive and cornering has a much better, positive feel. The difference is absolutely amazing.

JD,
Thanks for the unsolicited "testimonial" on radial vs. bias-ply tires.

I often 'lurch left' and 'lurch right' on the 25 yr old bias tires that are on my clipper. It is uncomfortable as I navigate 'seams' in city streets, and worse yet on 2 lane hiways. I have forgotten how scary a 2 lane state highway is at 60mph with oncoming traffic in the next lane.

Anyway, radials are on my 'add for safety list.' I have added seat belts and the turn signals. Can't imagine driving w/o them. Your comments remind me that radials need to be on my list for next year.

DanL
PS: Will these radials be taking you to Brandon?

Different folks and cars/tires with different histories and care have different experiences. Certainly OLD bias ply tires will handle very poorly and can be dangerous. Though it's generally recommended that radials should not be in service after 10 years, bias ply are sometimes stated to have longer life - can't say if that's true or just conjecture. The Dunlops on my 48 Custom were in service for more than 25 years, never needed air, never showed any age cracking, but when they were replaced with new bias ply the difference in handling was astounding.

I had new bias ply on my 56 Caribbean, switched to GoodYear radials because of short tread life on the bias; the front was always aligned "loaded" to specs, and I must say the handling has always been excellent, no big difference between the two types of tires.

Quote:

O_D, It may have been the age/quality of the bias ply tires, I can't say for certain. But it definitely handles well now!

Quote:

I'm taking the old girl to a transmission shop in about 20 minutes to see if they can handle the (front seal?) leak from the Ultramatic. If not, I don't see me driving to Branson with a case of type F in the front seat, adding fluid via a funnel and plastic tube while en route (although I can now steer easily with one hand). Most likely I will not be ready for an extended road trip by the end of the month. As my father used to say, "We'll see".

Some clarification needs to be made here. THe term "old" bias ply tyres means exactly what?????

Old REproduction bias ply or old PRODuction bias ply tires??????

Set + caster into the front suspension instead of the factory spec - caster. Don't believe it???? You all just proved it to yourself when u went to radials and here is why:

The bias ply tire has a lot of foot drag. MEANING that as the car goes faster and faster the contact surface of the tire to the road moves BACK toward the rear of the car. THIS IS THE SAME as jacking more negative caster into the front suspension.

The radials have near minimal foot drag. So the radials simulate closer to zero or positive caster.

Negative caster causes steering hunt. Positive caster offers resistance to road and wind compliance thus reduces or eleminates hunt.

So the next question is: if that is true why did the Packard gods (as well many other mfg'ers prior to mid 60's) set negative caster????? After about 1965 most cars went to positive caster.

I let someone else answer the question.

THe term "old" bias ply tyres means exactly what????? Old REproduction bias ply or old PRODuction bias ply tires??????

Dunlop was a "major" tire maker, so in the context of my statement "old" meant OLD front line, production tires. But the situation is probably more acute with reproduction bias ply tires, some, perhaps many, aren't made to the standards of the best bias ply tires in their heyday.

'Old' in the context of my original message referred to Duralon DS Premium J78-15's (made in the USA) off the rack tires from the period (70's?) with 1 inch whitewalls. Not WWW reproductions.

The car's front end alignment is and was per factory specs.

I've got lots of mechanical work to do to get to hiway-worthy status on my Clipper. Good luck, JD, on the case of Type F to get to Brandon. (I'll help you get a case to get back home.)

PackardV8, if I am understanding your post correctly, I think I have more than enough "steering hunt" and need more '+ caster.'
I drove a 39 LaSalle recently with 7.00x16 Firestone bias-ply tires. It drove much smoother than my Clipper. Suspect I need steering adjustment (along with some front end re-building).

DanL

PS, Must confess, I am still wondering about radials though!

Dan, I had a thread going last week where we discussed how much a correct alignment will improve the "wondering" problem. My Clipper almost drives like new after correcting years of pot hole jolts! The new radial 7.00 X 15's helped too, although I saw a bigger change on my '52 Mayfair with radials. The change there was truly amazing! I think the narrower tread width on the 7.00's minimize the noticable change, but they are still much more "secure" to the road. To me, installing radials, like seat belts, is a safety issue.
We're leaving in the morning on a week-long tour with the '41. This will be the first long drive away from home for the girl, so wish us luck!