Seems that our good friends at Harley Davidson used exactly the same threads and cap nuts on their late 50's big twin gear box speedo drive unit 1:1 ratio as did Johns-Manville on their 13-16 speedo heads.
I have the wheel gear in place ( 64T 9P JM - 4341)
and using the Harley Davidson drive unit and a good covered Bowden cable should be good to go EXCEPT for one thing, what size is the fibre gear to suit it?
David, The number of teeth on the pinion gear depends on the diameter of the tire. If the diameter is 28", then 18 teeth, 30" = 17 teeth. I hope this helps. Russ Furstnow
Excellent answer, OK who as the 17 tooth fibre gears.
OOOps, what did Russ just say, l think l thought before l checked.
Do you mean physically measuring the wheel, tread to tread to get the right size or will my 24" 30 x 3 tire be the right number.....measured ..... equals 30' ..... perfect.
Thanks Layden, look forward to that.
You need to physically measure the diameter of the tire to determine the proper pinion gear. Please keep in mind that the J-M formula is different from the Stewart, where the road gear determines the correct speed, not like the J-M/Jones units where the PINION gear determines the speed. I hope this helps.
thank helps clear up those Stewart/others differences.