Re: My first build to sell. Sold.
The seat post is actually the stock post cut and bolted back together spaced by a piece of U-channel steel. It came out very strong, I wasn't able to budge it with my near 200lbs bouncing on it for all I was worth. I also cut about an inch and a half of the top of the seat tube so the post was inserted as far as possible and there was less stress on the frame. The bolts I used were extras from a thru axle project I did on another bike.