measure Roll out .. natural materials approach ..
ride thru some dog poo, and measure the distance between the marks on the sidewalk
when the poo patch on the tire comes around again,
and makes another couple marks on the sidewalk.


if you really want precision lay down a thin piece of tape, put a dab of paint down.
pull up the tape, that leaves a clear line in the paint dab..
then there is that line to measure between.