Wow, quite a build! Are you gonna reinforce the seat post with a gusset or anything? If not you probably should, especially with that much leverage on it. My last boardtracker I made has seat post like that MAYBE about 3/4's that size almost 1/2, good steel, overwelded, and at a stronger angle than that and its already trying to bend on me

and I only weigh 165!! :| So I'm trying to hurry up and find a good piece of steel to maybe gank from my bad neighbors yard to make a gusset out of. Just thought I'd bring that'n up, hate to see any unneeded oopsies happen to such a pretty bike.