[Chrysler300] Cooker Radial

Hi all:

To go along with the below e-mails, I converted my 300F to 15" wheels almost 20 years ago in addition to installing disc brakes. I cannibalized 14" wheels I purchased from the wrecking yard for the rims and welded them into the 15" rims to accommodate the 14" wheel covers of the F. See my article covering the conversion to disc brakes in the Tech section of the Club's web site. The wheel conversion is part 2 of this article.

I plan on being at the Meet in May and will have my F there. I will be more than happy to discuss this project with anyone.

Dan Reitz

Bell Canyon, CA

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In a message dated 4/4/2018 6:20:20 PM Pacific Standard Time, Chrysler300-noreply@xxxxxxxxxxxxxxx writes:

I think those of using 14 inch wheels on older Chrysler, Dodge, Mercury, Pontiac, Oldsmobile, etc. are pretty much out of luck.

Last Production tires in the 235/75R14 and 225/75R14 were made by Cooper and their related brands such as Mastercraft, Multi-Mile, etc around 2005. The only current option in 235/75R14 (replaces 8.85-14 or 9.00-14 or 9.50-14) that I know of is American Classic sold by Coker as well as others.

And as you note, several people have had problems from separation to out of round / major balance problems with the low volume specialty radial tires in these sizes.

An argument against such low volume specialty production tires as well as the bias reproduction tires is that these are very old technology and not generally subjected to the same level of quality control as high volume production tires. Most if not all of these still use the old clam shell molds.

This may be less of an issue in bias tires, but when early bias belted tires were introduced around 1968, Goodyear had done their homework and invested in technology while the other of the big 5 Tire makers (Firestone, Goodrich, General, and Uniroyal) and the private brands rushed to catch up. The same was true for Radials - Michelin had introduced them to the US in the mid 60's and Goodrich followed in 1966. The other of the big 5 were still focused on Bias Belted and had to rush radials into production in the late 60s and early 70s.

As a result there were many recalls and radial tire designs were iterated multiple times. One of the more significant improvements was going from the old clam shell tire molds to the segmented molds which better accommodated the steel belts. As I said, unfortunately most of the low production specialty tires are still made in the older style clamshell molds. Furthermore, they are generally made in small batches and do not benefit from continuous production - this tends to further aggravate consistency in product compared to tires which are mass produced.

A Coker Classic 235/75R14 I have with a 2001 production date has never seen the ground. It was made in Mexico in a clamshell mold. Further it is very heavy compared to any one of 4 brands of mass production 235/75R15. I have never dealt with American Classic - they look similar, but again I have no example to evaluate - they may be superior, but having lived thru the 60's and 70s with direct contact to radial tires at that time, I would not personally want a clamshell made steel belted radial. You can tell if its a clamshell mold - there is a visible splitline in a new tire with excess rubber flashing running circumferentially as opposed to multiple split lines running transverse to the tread.

The biggest production grade tires are 215/75R14 (26.7 inch OD - replaces 8.00-14, 8.25-14 - 27.5 to 27.7 OD) available in narrow whitewall. They probably have load capacity to replace 8.50-14 (28.1 to 28.4 OD) but will be significantly lower diameter and of course radials squat more than older bias ply tires. If you choose this option, I would make sure I stayed away from the multiple lines of Chinese made tires that come and go under different names. I have gone with Hankook H724 where the 215/75R14 was appropriate.

But I think the best option is to switch to 15 inch wheels if possible. Here you have the option of 225/75R15 which is a good match for 8.50-14 diameter or 235/75R15 for 9.00-14. And depending on size, Hankook, Nexen, Toyo, Maxxis and Cooper have these available in narrow whitewall in tires produced in Indonesia, Korea, Japan, Taiwan, and Mexico respectively. The last Cooper I have with a date code of mid 2016 was still made in clamshell mold in Mexico. And if you want to go Diamondback there are many other blackwalls in these sizes.

On 4/2/2018 3:37 PM, Gary Gettleman gary.gettleman@xxxxxxxxx [Chrysler300] wrote:

In preparation for the spring meet, need to replace the old 900x14 bias ply tires with a radial.

Diamond Back is still in process with their 235/75R14 and no info available for when the long of tooth project will happen.

I purchased a set of the Coker radials back in 2001 and after 3 had separated (not good!) within few months of purchase they swapped out for the 9:00x14, too their credit no charge for tires or shipping.

Would appreciate any feedback from members on the radial tire subject

Thanks to all.

gary gettleman/Santa Cruz