I've got an '03 1150 with servo ABS, the front wheel has a sensor ring (mounted to the left disc mounts), the rear sensor mounts into the bevel box and (I suspect) detects the passing of the gear teeth therein.
I fear that doesn't help. since it doesn't look like an answer to your question. But no measurement of my bike would. Were the earlier onews that much different?
I've got an '03 1150 with servo ABS, the front wheel has a sensor ring (mounted to the left disc mounts), the rear sensor mounts into the bevel box and (I suspect) detects the passing of the gear teeth therein.
For a start you haven't stated the model of bike and the year. They are not all the same.
I'm probably wrong here because I have a Post sep/2002 bike with EVO (servo brakes ) so I am assuming you are talking about a pre 2003 model with solid ABS rings.
I thought the front ABS ring had 6 fitment holes and the rear ABS ring has 8 fitment holes.
just lightly mount what you think is the front one with a couple of disc bolts and (including the disc) onto the wheel and set it into the forks and nip up the axle bolt
if it's around a mm off the sensor you chose correctly and the other one is the rear