[machittome]

Gang,

This may have been discussed before.
The rule book is clear under Chassis item number 12 as far as red line radials, letter size tires, metric size radials and low profile metric radials. I've been seeing tires with red lines and wide white wall tires that appear to have a radial tread design and no visible size marking on the out side side wall.
Can you declare it a radial from the tread design when no size marking is visible?
Documentation may show a red or wide white wall but the tread may not be clear or identical.


Regards,
Ken

[Shop Rat]

Ken, I copied and pasted your question and sent it to Eric (Rick) Marsh, the guy that teaches the CJE class on tires. Here is his reply to your question.

Hello Ken, I have been including this subject in my tire CJE now for about a year. There is a company out there, I believe, called diamond back tires. They make a wide white radial design with a smooth outer sidewall.

Bias ply tires have a sharper angle of transision from the sidewall to the actual tread. Radial tend to have a smoother transision as you would note when looking at the tires on your modern vehicle.

If you are unsure of the type of tire due to a smooth sidewall w/o markings, you can almost bet that the tire came from this company whose primary market is modified vehicles (the owner has little use for AACA judges when I spoke with him in 2008).

You can also see the markings when you look under the vehicle at the back side of the sidewall.

Rick Marsh

Additional information from Rick I received tonight by e-mail.

One point of clarification. A Bias ply is a bias ply but, a radial maybe a radial or a P Metric radial.

If you walk up to a vehicle with a wide whitewall, it should generally be a early '50s car or older. If there are no markings on the sidewall, then a close inspection of the tread, as you pointed out, is in order.

If the vehicle calls for a radial (per the owner's manual or the B pillar sticker), the tire must match the documentation. Putting a P metric on a '69 Buick and taking the P off with a drummel tool doesn't make the tire a correct component.

On our show fields we should see bias plies, radials and P metric radials and, in all cases, they should match the documentation.
It may take looking at more than one supplier to make the matchup a reality.

Rick Marsh

[machittome]

Thanks Susan and Rick,

You are right. That tire company advertises a bias-ply look with square bias-ply style shoulders. They also mention their tires are labeled only on the inside sidewall. They make it hard as possible to tell it's a radial. It's hard to see any markings on the inside sidewall of a tire on a low profile car on a grassy field without a flash light. Wouldn't a correct bias ply tire have visible outside sidewall markings even with a wide whitewall? So we have to look for a size marking, and look at the tread and shoulder.
Well then, if it is a metric size radial tire then we must judge it as such. A radial is a radial! Correct me if I am wrong.

Regards,
Ken

[Shop Rat]

You are welcome and I will forward your thanks to Rick.

[machittome]

Susan,

Ask Rick what the difference is between the Metric radials and Low Profile Metric Radials mentioned in the rule book and P-Metric radials. There's got to be more to it than just the prefix "P."

Thanks,
Ken

[Shop Rat]

Ken,

I just copied and pasted your question and e-mailed it to Rick. I will let you know when I hear back from him.

[Semi-Intelligent]

A suggestion to anyone, judge or not, to attend Erics CJE on tires at your next national show. CJE's are held approximately 1 hour before judging commences on the show field. Just look for Eric and listen in. He provides a super lecture on tires. I attended at Hershey just to find out for myself how knowledgeable he is, and he is. He's also willing to listen to the students.

[Shop Rat]

S-I,

I hope you don't mind but I sent a copy of your post to Eric/Rick. People that teach others and volunteer their time to do so enjoy hearing that what they do is worth someone's time to learn.

I have known Eric/Rick for quite a few years and he is a great person. The handout he gives during his CJE classes is a great reference tool.

[Shop Rat]

Originally Posted by machittome

Susan,

Ask Rick what the difference is between the Metric radials and Low Profile Metric Radials mentioned in the rule book and P-Metric radials. There's got to be more to it than just the prefix "P."

Thanks,
Ken

Ken,

I just heard back from Rick. He is one busy guy. Here is the information he just sent for you. Hopefully this will be helpful.


The basic construction is similar. We started with radials which use a number system ie. 225/70R15. Along about the late 70s we started down the path of joining the rest of the world in the use of the metric system. The result was a re-measurement and adjustment to European standards. We called these P-Metric and production continues to this day.

About 10 years ago it was very difficult to find the "original" radials and people felt they had use the P-Metric instead.

Today, both are in production. Most of us just key into Google the size we are looking for and are lead to multiple sources.

Rick Marsh

[Shop Rat]

Originally Posted by Semi-Intelligent

A suggestion to anyone, judge or not, to attend Erics CJE on tires at your next national show. CJE's are held approximately 1 hour before judging commences on the show field. Just look for Eric and listen in. He provides a super lecture on tires. I attended at Hershey just to find out for myself how knowledgeable he is, and he is. He's also willing to listen to the students.

S-I,

As I mentioned I sent this to Rick since he rarely comes on the forums. Here is the reply that he sent for you.


Well thank you. It is always nice to receive positive feedback.

Thanks,

Rick Marsh

A note to anyone that takes a CJE class, please remember to thank the instructor when the class is over. They volunteer their time to help us further our judging educations. AND they have to teach several times a year to get ONE credit. And no matter how many more times they teach, which some of them are at every show, they only get one credit. Judges on the other hand get a credit for every show we judge at.