1955 F350 223 project
#16
06-28-2015, 10:46 AM
Edit - Mark texted me back that he's away today and will check back in here this evening. Stu
#17
06-28-2015, 02:58 PM
The rim profile is the main indicator, and then the drop center or semi-drop center profile. Here is the profile of all tubeless truck rims having the 1/2" sizing. This is true for 16.5", 17.5", 19.5", 22.5", and 24.5".
The very short rim lips, called a 15° profile, allow the tubeless tire to be stretched over and pulled into the drop center as it is installed.
The widow maker Firestone RH-5° is a semi-drop center rim. It has upright 5° rim lips, as do all tube type truck rims. The 5° in the widow maker name can be misleading for that reason. The 5° or 15° describes the angle of the tire bead seat. This is seen in the above diagram, and in this side-by-side pic that I marked in red.
The widow maker is unique because its rim and side ring join together at the semi-drop center. That joint is the only purpose for the semi-drop. Any time you see the combination of a 5° rim with semi drop center in a two piece design it is a widow maker. Pictures here.
A rim with a similar appearance, but not a widow maker, is the three piece Firestone "AR". The small locking ring makes the difference. These were common on F-7/8s.
On your 17" F-350 wheels, similar to the 17" widow makers supplied on F-3s and F-250s, the center disc is riveted to the semi-drop center. On bigger truck wheels the disc is attached to the flat surface of the rim. The first of the following pics is the F-3 widow maker, then the bigger truck type. Stu
Big truck.
The very short rim lips, called a 15° profile, allow the tubeless tire to be stretched over and pulled into the drop center as it is installed.
The widow maker Firestone RH-5° is a semi-drop center rim. It has upright 5° rim lips, as do all tube type truck rims. The 5° in the widow maker name can be misleading for that reason. The 5° or 15° describes the angle of the tire bead seat. This is seen in the above diagram, and in this side-by-side pic that I marked in red.
The widow maker is unique because its rim and side ring join together at the semi-drop center. That joint is the only purpose for the semi-drop. Any time you see the combination of a 5° rim with semi drop center in a two piece design it is a widow maker. Pictures here.
A rim with a similar appearance, but not a widow maker, is the three piece Firestone "AR". The small locking ring makes the difference. These were common on F-7/8s.
On your 17" F-350 wheels, similar to the 17" widow makers supplied on F-3s and F-250s, the center disc is riveted to the semi-drop center. On bigger truck wheels the disc is attached to the flat surface of the rim. The first of the following pics is the F-3 widow maker, then the bigger truck type. Stu
Big truck.
#18
06-28-2015, 03:21 PM
All correct. The 20" next to the 22.5" in the red marked diagram isn't identified, but would be one of several Goodyear rim designs that have split side locking rings. For pretty much the whole span of years that would encompass our trucks, all four wheel companies (Budd, Kelsey-Hayes, Motor Wheel, and Accu-ride/Accuride) used outer rims produced by, or licensed by, and patented by either Goodyear or Firestone. Neither company produced their own complete wheels until Firestone Steel Products Division began building their own under the Accu-ride brand, now Accuride, around 1960. Even today, many of the Goodyear designs survive and are used by Accuride. Stu
#19
06-28-2015, 04:16 PM
Lead Driver
Sorry, I missed your question answering the other. I don't have the available 17.5s myself, my friend Mark has them. His user name is thundersnow70. I'll text him after hitting send on this and have him drop by to connect with you. Stu
Edit - Mark texted me back that he's away today and will check back in here this evening. Stu
Edit - Mark texted me back that he's away today and will check back in here this evening. Stu
#22
06-28-2015, 08:41 PM
Lead Driver
#23
06-29-2015, 09:31 AM
#24
06-29-2015, 09:56 AM
Yup, your pic of the center disc riveted to the semi-drop center clearly shows it.
In an exchange of texts yesterday with Mark (thundersnow70) I mentioned that I had a pair of 17.5s a few years ago I was preparing to sell and found, upon removing the tires, that they had real bad (undetectable) internal rust that rendered them junk. I might suggest you have your two "good" 17.5s checked, and have dead tires pulled, before buying so you don't end up having half a solution. Stu
In an exchange of texts yesterday with Mark (thundersnow70) I mentioned that I had a pair of 17.5s a few years ago I was preparing to sell and found, upon removing the tires, that they had real bad (undetectable) internal rust that rendered them junk. I might suggest you have your two "good" 17.5s checked, and have dead tires pulled, before buying so you don't end up having half a solution. Stu
#25
06-29-2015, 10:15 PM
Tuned
#27
06-30-2015, 07:04 AM
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