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  • GeoffInCarlsbad
    Experienced
    • Jul 4 2015
    • 206

    Tire & Wheel Conversion Size

    Hi folks:

    Just getting back after health issues.

    Looking to source steel wheels for my 1961 T-Bird Convertible.

    Shop Manual indicates: 8.00 x 14-4 size tires.

    I measured the original hub caps and they are 14" so, I just want to validate the OEM wheels were 14". What's the proper width of the wheel?

    I will check with Coker for closest tire size, but does anyone else have any suggestions for getting original-looking tires and what their experiences have been?

    Thanks,

    geoff
    Geoff In Carlsbad
    1961 Thunderbird Convertible aka: Betty:cool:


    sigpic
  • dgs
    Super-Experienced
    • Feb 13 2003
    • 962

    #2
    Squarebirds also came with the same 8.00-14 tires. They are tall and skinny, unlike modern tires which are short and fat. The best match in radials are 215/75R14 or 225/75R14 and that's what most Squarebird owners are running. Both are going to be a bit shorter and a bit wider, however.

    According to Coker:
    the 8.00-14s are 7.7" wide & 27.59" tall

    The modern sizes can be calculated[1], although there is some variation:
    the 215/75R14s are 8.46" wide & 26.69" tall
    the 225/75R14s are 8.85" wide & 27.28" tall

    I hope that helps

    [1] - the first number is the width in millimeters, the second number is the sidewall height as a percentage of the width and the third is the wheel diameter in inches.

    So, for 215/75R14:

    Width = 215mm/25.4 = 8.46"
    Height = 8.46" * .75 * 2 + 14" = 26.69"
    DGS (aka salguod)
    1960 Convertible - Raven Black, Red leather
    www.salguod.net

    Comment

    • del
      Retired Expert Enthusiast
      • May 11 2010
      • 312

      #3
      Here is what the Coker Classic 215/75R size looks like on the car. These were mounted spring 2015 and I'm pleased with them.
      Attached Files
      Regards,
      Don Vincent
      Amherst NY
      1960 HT 352
      TBird Registry 34042

      Comment

      • bird 60
        Super-Experienced
        • Mar 18 2009
        • 1144

        #4
        Hi Geoff, good to hear you're back from your health issues.
        I have a '60 Bird & the tire size is 225/75R14 Coker Radials with a 2 1/2" Whitewall.
        I am very happy with the appearance, handling, & quietness.

        Chris....From OZ.

        Comment

        • GeoffInCarlsbad
          Experienced
          • Jul 4 2015
          • 206

          #5
          Exactly what I Expected

          Hi guys:

          I only expected the best answers from you all! Thanks. So I guess my last question is:

          If I buy 14 inch steelies, is there an issue with width or are they pretty much standard?

          ~g
          Geoff In Carlsbad
          1961 Thunderbird Convertible aka: Betty:cool:


          sigpic

          Comment

          • DKheld
            Super-Experienced
            • Aug 27 2008
            • 1583

            #6
            Glad you guys are happy with your Cokers.

            Guess compared to bias plys they are acceptable.
            I had Bias plys on mine (G78-14) from about 1994-2004. Put Diamond Back Radials on in 2004 - loved them (made by Dayton). Car drove SUPER - almost as good as a modern car and as well as my Ford E-150 van.

            Recently replaced the 10 year old Diamond Back radials with Coker Classic radials.

            Exact same size - no changes to the suspension, alignment steering etc.

            Car is all over the road - I don't like the tires at all. Used to be able to drive with one hand on the wheel and no sawing back and forth. Now I don't feel comfortable driving the interstate at 70mph with 2 hands on the wheel. I've tried different pressures with about 44psi working the best. Wish I had gone back with Diamond Backs..

            Just my 2 cents

            Eric

            Sure - they look fine but I would settle for looking worse and driving better.


            Comment

            • del
              Retired Expert Enthusiast
              • May 11 2010
              • 312

              #7
              Hi Eric,
              In my case I was replacing aged bias plys with the Cokers, so yes there was a big improvement in handling. I'm interested in your tire pressure experimenting, though. What pressure are other folks using on the radials? I did notice a bit of the "wandering" effect you mentioned when the tires were first installed last year, but I've either become used to it or it is less now that the tires are broke in.
              Regards,
              Don Vincent
              Amherst NY
              1960 HT 352
              TBird Registry 34042

              Comment

              • bird 60
                Super-Experienced
                • Mar 18 2009
                • 1144

                #8
                36 psi.
                Chris.....From OZ.

                Comment

                • dgs
                  Super-Experienced
                  • Feb 13 2003
                  • 962

                  #9
                  Originally posted by GeoffInCarlsbad
                  Hi guys:

                  I only expected the best answers from you all! Thanks. So I guess my last question is:

                  If I buy 14 inch steelies, is there an issue with width or are they pretty much standard?

                  ~g
                  A 14" wheel only tells you what the diameter is. They will vary in width & offset, bolt pattern, center hole, etc. The Squarebird wheel, I believe, is 14" x 5.5" wide with a 3/4" offset or 4" backspace with a 5 x 4.5" bolt pattern. I'm not sure if the Bulletbirds used the same wheel dims or not, but with the same tire size they are probably close.

                  Here's a good image showing what the terms mean. All of these dimensions vary depending on the application.

                  DGS (aka salguod)
                  1960 Convertible - Raven Black, Red leather
                  www.salguod.net

                  Comment

                  • OX1
                    Super-Experienced
                    • Feb 10 2016
                    • 557

                    #10
                    I recently put these on. http://www.summitracing.com/parts/HKT-10703/

                    Only a small whitewall, but they drive fine. No wandering, etc...
                    up to well over 70.
                    59-430-HT

                    Comment

                    • del
                      Retired Expert Enthusiast
                      • May 11 2010
                      • 312

                      #11
                      Originally posted by bird 60
                      36 psi.
                      Chris.....From OZ.
                      Thanks for the info!
                      Regards,
                      Don Vincent
                      Amherst NY
                      1960 HT 352
                      TBird Registry 34042

                      Comment

                      • GeoffInCarlsbad
                        Experienced
                        • Jul 4 2015
                        • 206

                        #12
                        DiamondBack v. Coker on '61 Bird

                        I am seeing mixed reviews regarding Diamond Back Radial and Coker's American Classic Radials.

                        I am preparing to replace my tires. The Cokers are appealing because they come in 8.00-14, OE size, but is the handling that much worse than the DB 215 75/R14?

                        Plus the DB's are about $22 each less expensive...so if anyone has any further reviews would love to hear about them.
                        Geoff In Carlsbad
                        1961 Thunderbird Convertible aka: Betty:cool:


                        sigpic

                        Comment

                        • dgs
                          Super-Experienced
                          • Feb 13 2003
                          • 962

                          #13
                          Originally posted by GeoffInCarlsbad
                          ... The Cokers are appealing because they come in 8.00-14, OE size, but is the handling that much worse than the DB 215 75/R14? ...
                          The 8.00-14 would be bias plays, not radials, and I think they would not handle as well as the radials of either brand.
                          DGS (aka salguod)
                          1960 Convertible - Raven Black, Red leather
                          www.salguod.net

                          Comment

                          • GeoffInCarlsbad
                            Experienced
                            • Jul 4 2015
                            • 206

                            #14
                            American Classic Radial 8.00-14

                            American Classic Tires offers an 8.00-14 Radial.

                            I found a local (Fallbrook, CA) supplier who also sources these tires, and similar.

                            Because they are local, I will be going through them and saving myself $'s in shipping by picking them up myself.

                            Below is Coker's link:

                            Coker Tire Company's award-winning Bias Look Radial American Classic tire is made in the USA and thoroughly tested to ensure superb quality for your collector vehicle. You can trust that American Classic Wide Whitewall Radial tires are ready for the road, but they're also ready for the show field with beautiful styling and a whitewall that is built in to the tire from day one. The genuine whitewall construction, along with the "pie crust" shoulder and vintage-style tread pattern give this tire the original look, while the steel belted radial internals make it the perfect choice for a car that will see plenty of miles. This is a tubeless tire, but keep in mind that tubes are required on some OEM and reproduction wire wheels.
                            Geoff In Carlsbad
                            1961 Thunderbird Convertible aka: Betty:cool:


                            sigpic

                            Comment

                            • GeoffInCarlsbad
                              Experienced
                              • Jul 4 2015
                              • 206

                              #15
                              Exploring going 15" Wheels

                              Hi:

                              Instead of going with 14" wheels, I am considering keeping the 15" wheels, and going with 215/75R15. The diameter of those tires more closely matches the 8.00-14:

                              According to Coker:
                              the 8.00-14s are 7.7" wide & 27.59" tall

                              The modern sizes can be calculated[1], although there is some variation:
                              the 215/75R14s are 8.46" wide & 26.69" tall
                              the 225/75R14s are 8.85" wide & 27.28" tall

                              the 215/75R15 are 8.46" wide & 27.69" in diameter. Theoretically that should work.

                              I currently have 15" Rally Wheels with 215/65R15's, whose diameter is 25.998" (hence my speedometer reads fast). The car came with these.

                              From a handling perspective, I'd prefer the modern size on the 15" wheel, and going with 215/75R15's.

                              Any thoughts?
                              Geoff In Carlsbad
                              1961 Thunderbird Convertible aka: Betty:cool:


                              sigpic

                              Comment

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