I forgot, I asked john Brain about the bearing race. he said the ones he had fit on straight tubes, and he apologised for not mentioning it. He said that Nova Cycles has a part called a unicrown race ring, that will allow you to use a regular bearing race on a straight tube so it doesnt move around. I thought I would mention that. you can also go to a fastener supply place and buy long shanked bolts that have 1/2 -13 thread ends for the spring rods, that way you dont have to weld threads to the end of 1/2 inch rods, you just cut down the bolts to the size you need. That was another suggestion.