Our Drag bike uses 2 magnets mounted on rim 180 degree apart and fork mounted sensor to show bike speed and computer sends signal from here to monitor ABS. we have this installed on front and rear forks/rims...
Screamin Beagle... not sure how this differs from your setup...
it's just the stock factory abs system...has the wheel speed sensor that acts like a spacer on the axle and the abs bearing goes on that side and the regular bearing goes on the other. Is yours a factory system? So if it's not then I guess that's how it differs. Man I love the internet