I think you may be right, mine was off the front wheel tho
On Sportsters up until and including 1972, the speedometer drive runs off the countershaft low gear in the transmission. The drive is a round insert through the transmission casing with a beveled rotating gear on the end that meshes with the low gear. A cable is attached which of course goes to the speedometer. The speedo drive gear rotates the inner part of the cable, which rotates the mechanism in the speedo head to operate the odometer and speedometer.
Last edited by Nitram_b4; 12-16-2012 at 07:11 PM.