Diamond Back radials on 1941-48 Packards/Cadillacs

[gearboy]

Anyone have experience running, specifically, Diamond Back 7.00R15 radial wide whites on, specifically, 1941-48 Packards or Cadillacs? What psi are you running? Do you note an appreciable improvement over bias plies on a correctly aligned front suspension in good shape? Any whine, thrum, or hum? Quieter? Any experience with this size Diamond Back on the above cars? [color:\\"black\\"]

[Guest Chuck Conrad]

I had a chance to drive a 47 Cadillac equipped with these tires on the last CCCA CARavan. I was very impressed. It handled great and the car was very quiet. The basic tire was a Yokahama radial. The white walls looked very good. The owner told me that he paid extra for a ridge to be molded on the sidewall, just outside of the whitewall. This gave them a very authentic "period" look. It was difficult to tell that they were radials. In fact, we parked the car beside another 47 Cadillac that had regular Firestone white walls on it. The Diamond Backs looked much better to my eye.

I have no idea what pressure they were running at, so I can't help you with that question. But when the time comes, I will definitely look into these tires for my cars.

[Buicksplus]

I have a set of them on my 1940 LaSalle. Mine are not DiamondBacks, I just bought the Yokohama 700R15's blackwalls from a local Discount Tire store. These are fairly rare tires, my store had to order them from the distributor, I paid $100 each for them, installed. Note that the Diamondbacks list for $195 less shipping, give or take a few bucks.

I just drove the car to and on the Glidden tour with these tires. I thought they were just excellent. These are much thinner tires than the 225R15 radials that I had on this car before. The steering is far easier. They also are very tall and look very much like original bias ply tires, except for the large black embossed lettering identifying them as Yokohamas. But we have gotten used to seeing blackwalls on the car. Of course, the Diamondbacks remove that lettering when they glue on a whitewall, so you can have your cake and eat it too -- though at a pretty high price.

Yes, the astute may note that the '40 LaSalle should have 16 in wheels -- but mine, like many, was converted to 15's at some point in the 50's when supply of 16 in tires became short.

Good luck, I strongly recommend the tires.

Oh yes, I put 30 psi in the tires, I suppose they could take more pressure, I think they are load range C. The dealer told me these tires were designed for travel trailers.

Bill.

[gearboy]

Thank you, gentlemen. This is exactly the sort of "hands-on," first-person, real-world, "Ask the Man Who Rolls on a Set" experience we're looking for. I say "we" because several Packard & Cad friends are waiting for me to be the rolling test bed before they abandon their Firestone and other bias plies. For some reason, the ONLY fellows we know hereabouts (the greater SF/Oakland Bay Area) running radials are several 1936-37 Cordites, who are all happy thus far; two of them even driving back to the A-C-D national meet in Auburn, Indiana.

One other hesitation: I've heard from some savvy-sounding veterans that radials are harder on our older suspensions than bias ply. Have any of you observed or heard of any increased suspension component wear?

Thanks again, Chuck, and a special word of congratulations to Bill for going blackwall. As we all know, in their day, perhaps one of our cars in 50 wore whitewalls; just look at any period newspaper or magazine street scene. And NO new cars, no matter how expensive, came with whitewalls during the 1946 and '47 model years (perhaps a very few during the last month of '47 deliveries). So if we're really serious about authenticity, perhaps we should all be docked points for whitewalls, or at least handicapped, with the nod going to blackwalls.

What color is your LaSalle? My '47 Super Clipper's black with skirts, and i'm thinking blackwalls would look right sinister.

I've looked in vain; is there a place online where we could see these Yokohama mommas up close and personal? Meanwhile, we'd love to see your LaSalle so equipped if you could post a picture or two! Always thought those final LaSalles were good-looking. (What became the '38 Cad 60S Fleetwood was originally intended as a LaSalle design.) The Europeans are more sophisticated than we are and learned long ago that a clean, elegant design doesn't need baubles like whitewalls. In the US, we have a tendency to load our cars with everything that was available to the point where at any meet or show we rarely get to see these cars as they really looked.

[color:\\"black\\"]

[Buicksplus]

Let me see if I can figure out how to get some pictures up: If this doesn't work, I will post again...

The first one is the LaSalle with 225R15 Wide Whitewalls. These are older Diamondbacks I bought several years ago. I never cared for the profile of these tires, they gave the car a definite street rod look.

The second image shows the new Yokohama Blackwalls. It took us a while to get used to these, but we like them now. It is pretty hard to make a LaSalle look bad. And as you say, most of these cars had blackwalls originally. My earlier WW's had faded and yellowed on the edges quite a bit too, another reason why I did not get the Diamondbacks this time.

[gearboy]

Thanks for the pictures, Bill. Spunky coupe. Is the Yokohama script in huge block letters? How noticeable is it? That'd be my only possible objection on a WWII-era car. We know Yokohama is actually a Canadian company, but we can hear the ribs from the sort of duffers who are still fighting WWII (but probably served in a supply depot in Kansas), overlooking that the Japanese-American 442nd Infantry Regiment was the most highly decorated in US Army history.

I know of a '40 Packard 180 Darrin, black with black top with blackwalls (7.00 x 16 Firestone bias ply). Very sleek: basic hood ornament; no flying lady or cormorant. No foglights. No grille guards. You really see the car, not the tires. The owner tells me that for everyone who appreciates the tasteful understatement, someone else tells him he's "supposed to" have whitewalls.

These "supposedta" types are a drag. We thought Model A Ford catalog restorations were for them.

Have you racked up enough miles on the radials to note if there's any increased i.f.s. component wear? [color:\\"black\\"]

[Buicksplus]

Gearboy:

The script is pretty large, probably 2" block letters. Of course, the letters are black, so they can't be seen from, say, 10 feet away. But when you get close there is no doubt you've got a modern Yokohama tire on there, you aren't going to fool anyone. The raised lettering is on both sides, by the way, so you can't hide it by turning them around. I suspect with the Diamdbacks, the raised lettering will remain on the inside sidewall.

We take long trips with this car and it has not been judged for many years. At this point we are far more concerned about how the tires work than how they look. The rolling circumference of these tires (700 Revs/mile) is more than the earlier radials I had. I think those were more like 750 revs/mile. That helps keep the revs down on the highway. And the steering effort is much much less with the new tires.

The Diamondbacks will definitely solve most of the appearance issues, but there is a pretty hefty price for that. Too much for this cheap car guy!

Bill.

[JLee]

This is an interesting subject that I have been following for some time. I think all of you have covered most points except for two. First, If you show a car at a CCCA National Meet, radial tires will result in an authenticity deduction. A minor point, I know, for those of us who enjoy just driving our cars. Secondly, I would strongly suggest, if you intend to use radials on your 60 year old wheels, check them carefully. A few years ago I yanked of the old and hard tires from my K1 Allard and mounted some Dunlop racing rubber that would improve the grip greatly, just as one would expect from a radial tire in street use. However this is a car I use on the track, and the first time out, I broke a wheel, ripping out the center and doing quite a bit of damage to the rear fender and corner of the body. Upon inspection, I found another wheel that was cracking. I had some new wheels made up when I restored the car. A radial tire will put more stress on the wheel than a bias ply tire, and wheels are cheaper than restorations.

Jon Lee

[gearboy]

White it's good to have a sanctioning body like the CCCA as a "higher court" to help maintain authenticity, there's no denying that when it comes to tires, judging is skewed to vanity. Every 1946-47 US Classic (and non-Classic) with whitewalls should receive the same mandatory point-deduction, unless the serial numbers show the car was produced during the last month or so of '47 production. No cars were delivered with whitewalls during that period. In all other years, blackwalls should always be given an edge over whitewalls. Perhaps one car in 50 had whitewalls, fewer still in the '20s. Many people considered whitewalls tacky, ostentatious, even a little fruity.

Meanwhile, let's say Bill's '40 LaSalle was instead a Full Classic '41 Cad Series 62 or 60S. It'd seem ludicrous and phony to dock him more points for wearing a bias-ply-sized and dimensioned Canadian blackwall radial instead of a crummy Vietnam- or Mexican-made bias-ply slathered with a whitewall and a US company logo/script.

By the way, same with fog or driving lights. You hardly saw these things on cars back then, but today, everyone tacks them on.

Look at photos of major city Packard agencies, for example. You'll see Packard Twelves of all body styles parked on carpets with potted palms in the background, and the cars have blackwalls and the base hood ornament almost never seen today, not the flying lady or cormorant.

If the radial tire is in a non-metric, bias-ply size, as on Bill's coupe with its 7.00 x 15s, there should be no more point deduction than there is for using multi-viscosity oil instead of straight weight, using a modern quality corrosion inhibitor instead of soluble oil in the cooling system, or having safety glass in cars which originally didn't have it.

Finally, this dichotomy of "those who drive their cars" vs. "those who show their cars" is wearying and a real turn-off, unless the CCCA's major thrust is over-restored trailer queens purveyed by wheeler-dealers and members whose business/livelihood is connected to the auto restoration/vanity industry. [color:\\"black\\"]

[Buicksplus]

Gearboy:

I agree that the days of the tire deduction should probably pass us by. I believe VMCCA decided to eliminate the radial deduction this year. They are definitely a driving rather than a showing club, so it made sense to them. I imagine CCCA is under much less pressure to allow radials, because many of the listed Classics don't have radials available in the sizes they need. The later Cads are one obvious exception.

There is no such thing as a "restored" tire, they are all new and nothing like the originals. I would only deduct if the tires were obviously improperly sized or "inappropriate" for the car. Imagine, for example, a Packard 12 with big snow tires all around!

I have always objected to the hose clamp deduction. I never understood the point of putting repro hose clamps on my car. They don't work very well. The modern ones are better, cheaper, and hardly detract from the appearance of the car. So we go out, buy costly repro clamps, and put them on just to avoid a small deduction. Many take them off after the show, especially if they actually drive the car.

Such is the nature of the hobby, all the clubs have their rules. There are a lot of folks like us who have pretty much withdrawn from the world of judging. It is too much hassle and not particularly enjoyable to me -- either as an entrant or judge. I have done both many times. I now prefer to kick tires at the shows and hang around the hospitality room!

Bill.

[Twitch]

I've found any radial is superior to any bias ply tire on any car I've had. I would never mount a non-radial on any car I own.