^copper depicted, as I had some lying around. (10:1 ratio per Lee McCormack’s recommendations). The leg is 1′, the arms 5′ each. Note these rollers are little peaky, and therefore not “rollers”…yet. Now they are, because more soil was added to round them off:
These galvanized pieces would be cheaper (I wouldn’t recommend pvc, as its liable to bend/sag):
Various lengths could be built and and marked with tape for different roller heights, e.g an 8″, and a 12″, or a 12″ and a 12.5″. The arms could be marked as well, or have arms for specific berm arc radii also, sticking the leg in the ground a few inches, and rotating the arm to get that perfect arc…”the amazing diy pump track t-tool is 3 tools in one…maybe 5…on sale now at your local hardware store…”
The smartest way to get grades on trails, or dial the pin flags, is with a 100 inch or 50 inch level and a tape measure. With a 100 inch the measured rise is the percent as read, and with a 50 inch the measurement needs to be doubled for the percent grade.
The pipe tool could also be used for pin flag trail layout. A 10′ section with a 1′ leg at one end is a 10% grade…All you would need to do is attach a bubble level to it. A 7″ leg, 7%. And it might just inspire a roller or two out on the trail ;). (link to M Level depicted below)