OK, once we decide what length and what the head rake will be, its time to add our basic frame sticks to attach the front to the back. I used 2 sticks of 1 1/2 inch heavy wall square tube for the framework. I found after some trial and error that my frame tubes need to run all the way back under the wishbone legs to the point where they start to turn up just a few inches from the end where the bolts hold the tranny in place. Run your sticks as far forward as you need for the length you want. Doing it this way gives you several inches of weld area for your main frame tubes. This makes a strong frame to build off of. It allows your Trike to sit on the frame, not just attached to it. But this is not the only way to build a frame. I just think this is one of the best ways. You can do yours any way you like.
