Originally Posted by wsteve464

My thoughts on the seat tube, If you are going to buy a new tube get a double butted tube for strength around the seatpost or use the tube you have and add an external tube a few inches long at the tube junction. If the customer is a heavy and powerful rider it would give me peace of mind that the frame would not come back in year or two of hard use for a crack in the tubing. I would also go with a larger internal diameter and use a shim to make the post fit as it avoids the need to ream the seattube after building the frame, at least for me when I braze the frame I always get a rough surface inside the tube, maybe welding is different.