As I get ready to send my '15 front wheels off to be re-spoked, I am aware of the noticeable differences in my old spokes.
As background, we began buying and getting wheels given to us by ranchers in the 60s and later. Obviously this 1915 "T" has wood felloes.
When we started restoring the car about 25-30 years ago the wheels were a carefully constructed "compilation" of matching solid parts from many many wheels. I was not in state during the time the wheels were done so I wasn't able to see each step my dad took, but was there off and on. All of the wood was original except the shim that was added around the outside of the felloe.
I have re-read an article written by Gary Hoonsbeen for the 1977 "The Vintage Ford" Magazine and am aware of the general changes in spokes in the first years and the change from oval to round in the very early 20s' as well as the taper changes in each spoke and the dishing standard for the front wheels at this time.
The interesting thing is the significant variance of diameter as well as oval in complied spokes in my two front wheels. Obviously they were made in different locations and are not all the same though they would likely have been the same for an individual wheel.
Is there an "accurate" size for the period?
Noah Stutzman has said he will pattern them off of a spoke I have so would like to use the most accurate pattern possible.
If there is a trusted resource, I would sure appreciate being pointed to it.
Even though you plan on sending your wheels to a competitor I will try to answer your question.
Most likely there is an official dimension for the spoke oval in the Ford archives. However making wheels for Fords for about 37 years it is evident that that spec was not followed to the letter.
Today I measured an original 1915 wheel section. One spoke is 1.040" by 1.140" and the one beside it is .952" by 1.085". The measurement was taken about 3/4" from the felloe. The variation may be due to sanding during a restoration but I doubt it because the one is uniformly smaller except at the hub end where both are 1.25" thick. I measured one of the spokes that I make and it is .985" by 1.140" for a nice oval.
So why did this occur? I believe it was because of the huge volume of spokes needed and the machines that produced them. They most likely were made on an automatic lathe with a oval cam on it, one spoke at a time. So a minor difference in the oval barrel occurred with each sharpening and set up, along with wear on the cam. The hub end was machined later and the miter cut, finally the outer tenon was cut.
Another factor is that no one company made all the wheels. Kelsy, Hayes and Prudden had their own factories with their own machine set ups. I believe in 1916 Ford made about 350,000 cars that used 3 million wheels and therefore required 36 million spokes.
I have seen spokes for the 1914 through 1916 ranging from a skinny oval to almost round. Most taper a little from the hub toward the felloe. Most spokes from 1910 to 1913 were tear drop shaped rather than oval and gradually got a little heavier in cross section. The 1909 wheel could have a skinny tear drop spoke or the real early ones followed the NRS spoke pattern which is a very skinny double taper tear drop about 1" by 3/4" at the felloe.
So, what is the answer to your question? As I said earlier there probably is an official size but in practice it was not followed to the letter. I would recommend that you send the oval spoke you like the best with the metal parts to be used as a pattern. That way you will be happy with the end result.
Calimer's Wheel Shop
Older post with print on early oval spoke dimensions might assist some.
Bill, to say this is a bit embarrassing is quite the understatement. As you can tell, I have no experience with professional shops. My dad restored nearly 7 cars in his retirement. I got to be his helper since our first 1927 Model T. I consider myself more of a mechanic but he was an artist. Were he alive, I believe he could have walked me through it as he did toward the end of his life when I let him help via facetime and he "bossed" from his chair. So now I have to send them off.
Thanks so much for you help. It seems like your suggestion makes sense. Choose the spokes I like the best on the back wheels then find a matching front spoke and send it in.
I just hope i feel safe when they come back.