Radials instead of Bias Ply on 67 BB Convt

[Don M.]

Guys, I am done competing with my 67 435 Convt, now I am going to drive it, no more serious showing. I want to switch from the Factory size Bias Ply Redlines, to a radial RedLine tires, maybe consider one size larger, but I don't want any chance of the tire hitting the body anywhere. Lets face it, there are some radials that just don't look right. What is everybody's choice for a nice radial, that isn't ridiculously expensive. Somebody told me that Coker makes, what he called a bias look radial??? Make sense, and body hear of such a thing? Sorry something that is good handling wise, and looks good.

[Leif A.]

Re: Radials instead of Bias Ply on 67 BB Convt

Diambondback has several brand name tires that they can install a redline on for you. I run 215/70R15 on my '67. Second set from them...very satisfied. No rubbing issues whatsoever.

https://dbtires.com/classic-car-tires/

[Keith B.]

Re: Radials instead of Bias Ply on 67 BB Convt

Coker has some shaky history on quality on their radial tires. DB has not and will not.

[Mel S.]

Re: Radials instead of Bias Ply on 67 BB Convt

I have heard some "shaky" thing about Coker. That is why I bought Diamond Back for my 66. Very helpful personal.
Mel

[Duke W.]

Re: Radials instead of Bias Ply on 67 BB Convt

If you want a serious performance tire the V-rated Avon CR6ZZ is the pick of the litter. Use the 205/70R-15 size. The 215/70 is only 0.1" taller, but the tread width is greater and might interfere with the fender lips.

Duke

[Don M.]

Re: Radials instead of Bias Ply on 67 BB Convt

Thank you Leif. I appreciate the photos, that's a big help, the info from Diamond Back is very helpful. I believe that will be my choice! I have non factory F41 replacement springs, I swear the car sits a little lower. That might make me want to do 205s instead of 215s. I will check the specs. Do you think its enough to make a difference? BTW, I even like the look of the tire. Thanks

[Don M.]

Re: Radials instead of Bias Ply on 67 BB Convt

Hmm, thanks Keith

[Don M.]

Re: Radials instead of Bias Ply on 67 BB Convt

Thanks Duke, I may do the 205, but I like Diamondbacks.

[Don M.]

Re: Radials instead of Bias Ply on 67 BB Convt

Thanks Mel, I like the Diamondbacks, what size did you do??

[Keith B.]

Re: Radials instead of Bias Ply on 67 BB Convt

stick with 205

[Donald O.]

Re: Radials instead of Bias Ply on 67 BB Convt

I have Michelin WW radials mounted on my original ralleys and Diamondbacks redlines mounted on TorqThrust Ds. I had cokers on them TTs but they were THE WORST tires I’ve ever had for balance, roundness, or seeing the tread literally self destruct. Their service was non existent. The Diamondbacks were made by Toyo in 205/75 R15 (all three brands were/are the same size) two tires took 0.25 ounces to balance and two took ZERO to balance. They drive straight, true, quiet with way more grip than I will ever need cruising. I have no need for a speed rated tires, as my racing days are over. I went with the redlines as my 67 originally came with them. I had a set of bias redlines in 7.75-15 but their highway manners were not acceptable even after re-balancing thrice, two alignments an a full rebuild of the suspensions. With the acquisition of the Michelin radials it became a pleasure to drive on the highway.
For judging I would put red line bias tires back on but driving I’ll keep the radials on.

typo on the size, sorry about that
Don

[Mel S.]

Re: Radials instead of Bias Ply on 67 BB Convt

Don
My tire size is P205/75R15
Mel

[Leif A.]

Re: Radials instead of Bias Ply on 67 BB Convt

The 205/75 tire is a bit taller and narrower than the 215/70...your choice but I like having a bit more "meat" on the ground.


Diameter inches (205/75)27.11" (688.5) (215/70) 26.85" (682) -0.26 (-6.5) -0.9%
Width inches (205/75)8.07" (215/70)8.46" 0.39 (10) 4.9%
Circum. inches (205/75)85.16" (2162.99) (215/70)84.35" (2142.57)-0.8 (-20.42) -0.9%
Sidewall Height inches (205/75)6.05" (153.75) (215/70)5.93" (150.5)-0.13 (-3.25) -2.1%
Revolutions per mile (205/75)744.04 (462.32) (215/70)751.13 (466.73)7.09 (4.41) 1%

[Jimmy G.]

Re: Radials instead of Bias Ply on 67 BB Convt

I have a set of Cokers on a 57 Chevy Convertible WORST tire I have ever purchased by a long shot

[Duke W.]

Re: Radials instead of Bias Ply on 67 BB Convt

The 205/75 tire is a bit taller and narrower than the 215/70...your choice but I like having a bit more "meat" on the ground.


Diameter inches (205/75)27.11" (688.5) (215/70) 26.85" (682) -0.26 (-6.5) -0.9%
Width inches (205/75)8.07" (215/70)8.46" 0.39 (10) 4.9%
Circum. inches (205/75)85.16" (2162.99) (215/70)84.35" (2142.57)-0.8 (-20.42) -0.9%
Sidewall Height inches (205/75)6.05" (153.75) (215/70)5.93" (150.5)-0.13 (-3.25) -2.1%
Revolutions per mile (205/75)744.04 (462.32) (215/70)751.13 (466.73)7.09 (4.41) 1%

Revolutions per mile cannot be computed from dimensional data. This is because pneumatic tires deflect under load, so actual revs per mile that manufacturers measure on a tire dynamometer are usually about 3 percent less than the "rigid body" revs per mile that you compute from static inflated diameter.

For a given size most tires conform to Tire and Rim Association dimensions, which are in a narrow range and measured revs/mile follow suite. Most year AMA specs list revs per mile for OE tires and spec sheets for tires that you find on manufacturers' and retailers' Web sites usually include measured revs per mile.

Typical OE and replacement sizes are as follows.

760: 6.70-15, GR70-15, 225/70R-15
766: 205/75R-15
775: 7.75-15, F70-15, 215/70R-15

In most cases the speedometer gearing did not change with the slight differences in revs/mile during C1-C3 eras, but a few did.

Duke