seat post
i dont know how much you weight, but i weigh around 185 and i had the stock seat post on my lowrider bent at a machine shop for 10 bucks. then i mount a comfy cruiser seat cuz i dont like the way bananna seats and sissy bars "clutter" up a bikes look. it hold me up just fine. i also had some 1/8" walled steel tubing bent at the same angle for some of my gravity speed bikes, ya cant put a seat clamp on em but i dont use those for seats anyway. dude, im sure that bike is fun to ride, but please be careful. a 10 pound lead battery on a bicycle, only fastened w/ rubber ties, and the rest of the additions you made look really dangerous. if you call that a gravity bike then you hurt yourself or someone else you'll shed a negative light on g-bikes, and thats not even a gravity bike. i have a thread here in alt bikes that has pics of one of the bikes i finished recently... THAT is a stock g-bike. fast eddie outty