August 15, 2011
Classic 1924 Harley JD Motorcycle & Corbin Speedometer
Wow, there is a lot more to learn about Corbin speedometers and classic Harley motorcycles than I thought. I have owned a lovely original paint 1924 JDCA Harley for more than 20 years and never done much to it other than sort it out and get it running properly. And it has never had a speedometer as long as I have owned it.
Because it is all original I never really wanted to do anything other than get it and keep it running well. I replaced the rotting original tires with fresh rubber and swapped out the incorrect primary cover for the right one for a 1924. I also swapped the Indian carburetor that was on it for a proper Schebler one. And that’s about it.
I have ridden this vintage Harley around the racetrack at Mid Ohio at the AMA Vintage Days celebration to salute the founding of the American Motorcyclist Association (founded in 1924 the same as the year of this Harley JDCA) and wrote about the experience in the pages of American Iron Magazine.
And I rode it in the Pewter Run in the back roads of New Hampshire a couple of years ago. It was the oldest bike that year and I won the event overall coming in less than 30 seconds from a perfect timing without the benefit of a speedometer or stopwatch! I also wrote about this in American Iron Magazine. After that I have given a lot of thought to getting a speedometer so I have some idea how far I have ridden and at what speeds. But I have never gotten around to anything more than considering it.
About a year ago I was fortunate enough to buy a non-runner 1926 Harley J motorcycle. I had not been looking for one, but this sort of fell into my lap at a very reasonable price. It had a nice looking 80 mph Corbin speedometer and all the running gear to make it work properly. I took a number of items off this ’26 Harley J, including the Corbin speedometer head, mounting bracket, cable, drive and ring gear. It all looked to be original and in good condition. I inspected it and put it away in a box for later use.
A few days ago I had some spare time and rolled the 1924 Harley JDCA up on the rack and pulled out the box with all the Corbin speedometer parts. Installing the ring gear on the real wheel is a dirty, greasy job that is not hard but does take some time to properly center and attach to the wheel spokes. The drive gear slid on rather easily, and the cable attached and routed up the frame to over the gas tank. But that was the end of easy.
There was no way I could mount the speedometer head in a way that did not block the right side gas cap. I tried several ways and nothing worked.
I posted my dilemma on the Classic American Iron Magazine forum and on my Facebook page asking for help. Within hours I heard from Harley JD guru Mark Masa (thanks Mark!) who told me the mounting brackets are different from 1924 to 1926 as the gas tank designs changed after 1924.
1924 and earlier Harley application above, and 1925 and later Harley JD below. Note the gas caps on the right side tank are in very different places.
Once I realized that all I needed was an earlier style mounting plate I set about to find one. My friend Janus in Canada was the first call and sure enough he will get me the right bracket in a few days. Problem solved (I hope). More on this very, very long term project as I progress.