How to figure proper amount of offset on sprockets

I use an aluminum "C" channel that is either .25 or .375 inside width so it snugly fits over the edge of the rear sprocket and clamped. Then simply use a caliper to measure from the edge of the front sprocket to the channel. Easy math after that. I used a MotionPro chain laser as well, but measuring from a small beam of light to the edge of the sprocket wasn't as easy to use as the straight edge.

Just my .02

Cory