Tire advice?

[JoeKarasinski]

I'm looking into tires for the 60 and I know the originals are 820 x 15 with a 2 1/4 white wall. I can get that exact tire in US royals.

But I'm thinking since we plan to drive the car from here to Vegas in April that a radial tire would make more sense.

I can get
BF Goodrich Silvertowns 235/75R15 with a 2 3/4" white wall
American Classic Radials 235/75R15 with a 3" white wall
American Classic Bias Look Radials 820/15 with 3 1/4" white wall

So My questions are has anyone used the these bias look radials and what do think of them?
Am I nuts for even considering the US Royals with a 5,000 mile trip ahead of me in April?
Should I just play it safe and go with the Silvertown or the American classic Radial?
Is there something else I should be looking at?

[David Greenburg]

Everbody's got an opinion on this, but mine is that you should absolutely have radials.  I don't have personal experience with the bias look radials, but if you are that concerned with authenticity, you should also keep whitewall width in mind; not only is 3" and above incorrect; it also doesn't look right IMHO.  For my '60, I went with Diamondbacks because you can get the correct width.  I have been very happy with them.

[JoeKarasinski]

I forgot about the Diamondbacks, I don't see 2 1/4 white walls but I see that they do special orders, so I'll call them this week.

[David Greenburg]

They make each whitewall custom: they will do whatever width you want.

[76eldo]

I recently worked on a 60 with 235/70/15 Goodyear wide whites.

I don't know if they are made much larger than others in the same size but I had a lot of trouble getting them back on the car after inspecting the rear brakes.  Even with letting out all of the air they were quite tight getting back under the wheelwells. This was with the car on a 2 post lift with the rear suspension hanging down.

Possibly  225's would be a better choice.

Brian

[David Greenburg]

Brian-

I would think  235/70's would be somewhat wider, and therefore tougher to fit in the rear. 235/75's are a little tight, but they fit.  225/75's might fit. But are they the right load range for our beasts?

[Dan LeBlanc]

I ran 235/75/15 on a 62 Coupe I had and they worked well.  My 61 had 255/70/15 on it when I got it and I swapped them out during Hershey week for judging purposes to 8.20-15 bias ply (US Royal with the 2 1/4" white wall) and haven't looked back since.  The 255/70/15 that were on the 61 when I got it were the Silvertowns and when I have them on, the car shimmies like crazy.  With the bias ply tires, it's as smooth as glass.  I'm chocking it up to the tires as the shimmy was present with two sets of rims and road force balancing on both.

Should you choose to go the radial route, be sure to get an XL (extra load) tire because of the weight of the car.

[patton6606@gmail.com]

Hello Joe

I have 235/75  Diambacks with 2.25 white wall  and they ride like a dream.  They look great too.  I deflated for installation. 

[76eldo]

I think these Goodyears are just extra big.

I have Diamondbacks on my 60 convert and they are great.  I'll check the size and let you know if they are 225 or 235.

Brian

[TJ Hopland]

Has Joe got a model 60 or a 1960?   

The 235 is the width so in theory its going to be the same between a 70 and 75 series tire.    A 225 would be 10mm (little less than 7/16) narrower which I could see being just enough to sneak up in a fender.    I think a lot of the old tire sizes don't come out the same in metric like for the 70's cars they would be like a 230 which does not exist.   The bias tires seemed to be a little more round profile that narrowed at the tread where as the radials seem straighter so that could also effect how it fits. 

[TJ Hopland]

Are today's tires width measured at the tread or at their widest part when inflated?

[Cadillac Jack 82]

The BF Goodrich Bias Ply work just fine when I had my 1954 Buick Special.  Sure do Bias Ply grab ruts in the road and do odd things?  Sure do but that's how cars back then drove.  I took my car up to 300 miles away from my house without issues...you just have to make sure they are fully inflated and that your paying attention to the road.  If you don't care for the purist way of driving grab a set of radials.  Its all a matter of opinion

[Jon S]

I have the 235 75 15 B F Goodrich Silvertown Radials from Coker for 7 years now and cannot say anything bad about them.  They ride like silk, keep their white appearance for months and look great on the car.  Highly recommended.

[Eric DeVirgilis CLC# 8621]

My complaint with 235 75R 15 radials is that they make the car sit too low to the ground in addition to being too wide compared to the correct 8.20 15 bias tire.

If the new "bias-look radials" measurements are exactly the same as the 8.20-15 bias, and can be ordered with the correct whitewall for a 1960 Cadillac I would consider those.     

[Scot Minesinger]

Eric is right the 235 radials look much wider than an original bias ply tire.  However, on the lower cars say 59 thru early 1970 cars the wider tire looks much better.  I saw a 1969 Cadillac drive away on the original bias ply tires (can you believe it??!!) and they looked like a bicycle tire to me. 

If you are going for correct look to be driven on then get narrowest radials you can, if correct entirely but not driven on road get a custom bias ply with proper white wall, and if want best looking for the car in present day get widest radial with correct white wall (Diamond back).  However, I do not endorse bias ply tires on any car driven except on and off a trailer to the show field.  On bias ply tires many disagree with me and consider them safe, but we will continue to agree not to agree.

Further to this, the Goodyear (back when they made them 10 years ago), they measured and were easily noticeable with the eye to be significantly wider than other tires claiming to be 235mm.  Maybe the Goodyears were 235 at thread and the others accounted for bulge - I don't know.  I still have some Goodyears that are wider than other 235 tires.  Wish they still made the Goodyears, but it is not to be.

[David Greenburg]

The radials will make the carotid lower; like Scot I actually prefer that look.   But there are trade offs.  At least with a coupe, it's a little more work to get n without banging your head, and at least in my case, the tailpipes scrape slightly backing from my (not very steep) driveway onto the street. My '59 with radials did this, and I always attributed it to tired old springs, but my '60 does it as well.

[Jon S]

I've gotten used to the look of the 235 75 15's on my car and really like the slightly lower stance:

UPDATE:  If the 1958 Catalogue is remotely accurate, then the car in the picture sits lower than mine as evidenced by the hubcap to wheel well fit front and rear - especially noticeable in the rear:

[Dan LeBlanc]

Using the rear wheel opening with respect to the wheel disc is not a good indicator of vehicle stance altered by tires.  The centre of the wheel disc position relative to the wheel opening is driven by the suspension, not the tire size.  No matter how big or small of a tire is fitted does not change the centre line of the axle/wheel disc.

How well it fills the wheel opening and ground clearance are relative based on tire size.

An artist's rendering in a brochure and the actual finished product could also deviate.

[Jon S]

Dan -

That makes sense.

[Eric DeVirgilis CLC# 8621]

A fresh set of radials were on my '62 Coupe deVille when I bought the car. The car sat so low that everyone who saw it, myself included, thought the car needed a set of new springs - which it did not.

Also, entry/exit was more more difficult.

That said, the wider width radials tires don't bother me as much on later '60s Cadillacs but look out of place on 1964 and earlier models, to my eyes anyway.