Radial Tires On A P15

[larryconnors]

I have Coker wide whites on my P15. Although they clearly have very few miles on them and show no cracks in the sidewalls, I suspect that they are about ten years old. I plan to do quite a bit of driving this year and won't be surprised if they fail. I'm looking into radials to replace the tube tires. Will my stock wheels handle the radials? I think the radials will give me a better ride and improve steering and control. Does anyone have experience with radials on and old car?

[47heaven]

Larry....I switched to radials after my bias ply wide whites wore down. I also like to do a lot of driving in my '47 P15, not just take it out on a country road on Sundays. Anyway, I got tired of the tires getting caught in the ruts along the freeways and roads, causing my car to pull to one side. So I looked into radials for my 15" rims. I still wanted the whitewall look, so I bought some original white beauty rings that were an optional item for cars as of 1946 and on. Though the tires are a tad bit wider than the bias ply, I now have a more comfortable and safer-feeling ride, and no longer have to worry about being pulled to one side when driving over a rut in the road. This is a must for people who like to drive places. If you just take your car to shows and enter it in contests, then wide white bias plies would be more feasible.

[doctor dirt]

Just took off Coker 770x15 on my 49 Dodge. The 770 were slightly above stock size (760) for this car and  the Cokers had cracks also so off their going. I searched around alot and with some advice here (P15-D24) and assurance I bought my tires from Diamondback! Check out their site and give them a call and compare them to anyone else, I was sold! My 705/75/15 are a great match and I decided on 3" WW, They seem to be a better product than Coker and beat Cokers price by a few bucks also. Ask for "Old Man Bill"! HA!  Doc.

[Oldguy48]

Larry,

X2 on the Diamondbacks.  I've got 215/75R15's wide whites on my P15.  The car rides well, and they look great, but turning at very low speeds will build arm muscles.  I may consider looking into a power steering conversion.

 

Wayne

[mrwrstory]

X3,.....I've said before that Diamondbacks are the good value in many ways.  You might ask the "Old Man" about tubes as the stock wheels which are probably riveted may leak w/o tubes.

[doctor dirt]

Yes good point on the stock wheels.Gotta second that,  I have fairly new Coker rims about 7 years old with not many miles as far as I can tell. Old rims with a tube would be safer! Doc

[Oldguy48]

You're undoubtedly correct, although I am not running tubes, and have not had any issues at all.  My rims were sandblasted, then painted.

 

Wayne

[DCurrent]

Go Diamondback!!! Cokers will bring you grief and a bad ride for the money. Out of 100 guys I'd say 90% of them are unsatisfied with Coker.

[larryconnors]

Thanks for all of the feedback. Based on what you guys have said, radials are the way to go. Do you guys have any other suggestions of things I should do to make my 47 P15 two door sedan a reliable daily driver? I got it a year ago in running condition but it didn't exactly run like a well oiled machine. The only other non original thing I've done to it so far is to add seat belts and directionals.

[Reg Evans]

I'm another satisfied customer of diamondback tires. Mine on my 42 Dodge Coupe are 750/16 on the rear and 650/16 on the front. Much better ride and I like the look except I wish I had ordered 700/16's for the front.

Edited April 18, 2013 by Reg Evans

[Reg Evans]

 

[50 coupe]

Wow Reg, that is pure inspiration!

[james49ply]

I have been running radials on my 48 for 4 years, r215-75-15 they handle very good, have had no rim leakage as yet, and I run 15-20 thousand miles a year

[47heaven]

Well, if you get radials, you can save money and get black walls, but still have that original white wall look by putting those white wall beauty rings that were offered as an alternative to  regular white walls in late-1946. I have them on my P15, and many people seem to think they are white walls until I point them out. They were very common on Mopar cars of that era, as well as on Fords and Chevys. Even the ads featured them on the cars as well.

 

 

 

 

[Andydodge]

I have run radials on my 1940 Dodge since the mid 70's, o/k yeh its a hotrod BUT it uses the original style suspension.......the front tyres are 205/70x 14 and the rear are 275/65 x 15.........as for the 41 Plymouth I ran Coker Classisc Radials 195/75x15 and 235/75x15 on 15/6 and 15/7 chrome rims for nearly 5 yrs without a problems.......I know radials aren't original nor tradional but I like to drive my cars..........lol.......but we all have our preferences.........regards, andyd

[desoto1939]

At the recent AACA Annual Meeting and Lecture that was held in Philadelphia in Feb we had discussed the use of radials on our older vintage cars that came standard with Bias ply tires.

 

Several people spoke on this topic of discussion and the point that came out against the use of these tires on our cars is that the fron suspensions were not designed to properly handle the design of the radial tire. The geometry of the suspension was not designed to properly handle how the tires fles in a radial design.

 

I can not go into more specific but they do not recommended the use of radials.

 

Rich Hartung

desoto1939@aol.com

[BobT-47P15]

So.......I wonder if they offered any suggestions on modifications or improvements to the suspension system to

better accommodate using radials.

 

I ran some used radials for a time a few years ago, then went back to a new 

set of bias ply......for the look and the price.   The radials certainly did make the car handle

better and masked what feels like "play" in the steering with bias tires.  (I have not rebuilt the

front end.)  Am thinking of buying another set of radials, however.    I don't drive very many

miles per year, but get tired of fighting the road on trips we do make.   

[Don Coatney]

One nice feature of this new format is links to other threads using the tag feature. Look below for the

Also tagged with one or more of these keywords: tires, wheels, radials

 

and view the other threads.

[blucarsdn]

Interestingly, the topic of pro-cons for radial tires old cars is "again" running on the Ford Barn FOrum..

I have been running radials on my cars/trucks since the late 1960's. My '59 Fortd F100 has had radials on it since 1970 and my '57 Bird has had radials on it since '73.. My '39 Plym has had P205/65R15 since the day I got it running 1n 2004.

There are only a few minor issues that must be allowed for when using radials on old cars..

1. Make sure the wheels are the coreect width for the radial tire your are using.. The majority of radial tires require a wheel that is 6/ 6.5" wide... Many of the old car wheels are only 5" wide... The narrow wheel will cause the tire sidewall to be pinched in, which will alter the tread contact to the road.

I had the rims for my Plym changed to 7" on original centers so my hub caps would work.. The P205/65R15 tires require a 6.5"/7" rim...

2. The front end alignment has to be adjusted slightly for radial tires.. You should also make sure that the entire front end assembly, shocks, king pins, ect., are in top condition.

Myself, I can see no need to buy tires from mail order specialty houses, that is if you are not maintaining a con-course quality show car. Local tire dealers usually have several brands of radial tires in sizes that will work on the old cars.. The advantage of buying locally is two fold.. most likely the tires will be of current manufacture, and if you have a problem, you can talk eye to eye with the dealer, in lieu of customer (no-service) halfway round the world....Bill

Edited April 19, 2013 by blucarsdn

[DCurrent]

What psi are you inflating your tires too or anyone with radials for that matter?

 

I have been running radials on my 48 for 4 years, r215-75-15 they handle very good, have had no rim leakage as yet, and I run 15-20 thousand miles a year

Edited April 20, 2013 by DCurrent

[Niel Hoback]

  32 PSI in 225-75x15's on 4 1/2 x 15 wheels.

[_shel_ny]

32 psi 205 75R 15 on original rim. front D24

[blucarsdn]

In response to DCurrent' question about tire inflation pressure on radials..

Many people think that radial tires are low pressure tires.... Wrong! They are high pressure tires.. There are several points about tire inflation that most people overlook because they do not read the owners manual for their vehicle, and they do not read the pressure/load recommendations that is printed on the sidewall of the tire.

The pressure recommendations for most '50-60 model cars will be in the 28 psi range for normal "city driving".. The majority of owners manuals will state that the pressure should be increased for heavier loads and/or sustained highway driving.

Modern radial tires have the maximum pressure and load range stamped on the sidewall.. The normal load range for most car and light truck tires will be 1,300/1,500 lbs range at 38/40 psi. The P205/75R14 tires on my Bird are 1532 lbs @44 psi..

It is my normal habit to inflate my radial tires to the 35/38 psi range, higher on my SUV/pickup. The added pressure minimizes the shoulders of the tires being worn off, however, the big deal about proper pressure is that the air in a tire is what keeps the tire cool... Under inflated tires run hot, and therefore the added heat shortens the tire life.

I read a very interesting article several years ago about all the problems that Ford had with tire failure on their SUV's.. The article placed the blame for the tire failures, and subsiquent injuries/deaths onto Ford because Ford told Bridgestone/Firestone the price range that they (Ford) wanted to pay for the tires.. Bridgestone/Firestone complied with Ford's request, however, the tires did not meet the DOT spec.. When the failures started to appear, Ford sent out letters to their cutomers telling them to "lower the tire pressure" an average of ten pounds per tire.. Of course this info never made it to the 6:00 PM national TV news.

GM had given me the article in 2001 because I refused to take delivery of a new SUV with Firestone tires because of the problems Ford was having. My GM dealer pointed out to me that the Firestone tires that GM used were built to the DOT spec, having the load range and pressure stamped on the side wall...Bill

[Andydodge]

On the 40 Dodge the 205's are 30psi, the 275's are 26psi......on the Plymouth the Coker Whitewall radials were 35psi, I was told that the whitewall tyres needed to be kept around that psi for optimium wear..........have been running radials on the 40 dodge since the early 70's, the front suspension is basically a stock style front end, ie, Moog cast steel 41-56 style upper A arms, 40 Dodge lower A arms & uprights or spindle, 41-56 style stub axle, 1" thick adjustable sway bar, standard shock mounts, Austin 1800 rack & pinion narrowed 9"........as far as wheel alignment specs go I have always ensured that whoever was doing a wheel alignment had seen that I included a copy of the front end specs with the car when dropped off..........and that they DID know what they were doing........lol..............specs are specs, the parts don't know who they are so long as they are adjusted correctly.......lol.........The Plymouth when I bought it came with 6.00 x 16 stock wheels and crossplies........I'd forgotten just how much fun these tyres were.........I lowered the car and installed the Cokers & Chromies and it improved the driveability 100%...........but to each his own.........I'm a hotrodder and like upsetting the restorers that live around here.........lol...........regards, andyd     

[White Spyder]

I switched to Cooker radials and was amazed at the differance in handeling and ride.  If you want to drive your car then go with the radials.  If you are into judged shows and trailer it the original.  In my world a car was built to drive.  I do and will never go back.