First off it is my feelings they look better if frame rails are exposed. Typically I will make the seating section ~ 1" high and the hump 4 = 5 " above it . My preference is the American style not the English hump
What I need is .
width at the front,?
length of flat section,?
width at rear of flat ,?
does it get to full width before the back of flat ,?
if so how far back does it attain full width .
Material
Steel ?
aluminum ?
stainless steel ?
other options available
Hump for top frame tube
hump for tire clearance
For tire clearance humps I highly recommend pulling rear shocks and taking spring of 1and installing and compressing rubber bumper to figure out clearances .
pocketed mount holes