matt, i made one for a friend because he needed it to be 15' long and didn't wanna splice it. what i did was take a piece of red oak about 2" wide, i believe it was 13/16" thick. i set the table saw at about 15 degrees, i cut a scrap piece to see where to set the fence, you may need to play with that angle as well. i layed the 2" piece on edge and i shot for making the angle start 1/4" from the bottom and stop about mid way through the 2" width on top. this allows your foot to have a nice angle to hit coming up from the lower floor. then i did the opposite side, i think i used a larger angle for this one and started the angle about 5/8 from the bottom, which will leave the same 1/4" reveal from the floor as the other side. i also tried to make it work out so there was about a 1/2" flat surface on the top between the 2 angles. you may just need to do some test pieces on some scraps. finally i rabbited out half of the piece 3/8" deep on the second side.
hope that was clear....sorry so long.
let me know if you have questions
good luck
chris