The book was written when steel was cheap. If the project calls for "1-inch DOM tubing" and you have only "EMT conduit," the PDF includes a "Danger Zone" sidebar explaining when materials are interchangeable and when they will kill you. The "Evil Genius" Philosophy: Safety vs. Anarchy A critical note about this PDF: It is not for the timid. The authors openly state that you will probably hurt yourself, that your vehicle will likely be illegal to ride on public roads, and that you should invest in a quality helmet and liability insurance.
Because Brad Graham is an electrical engineer, the first third of the book obsesses over Ohm's law and soldering. If you are building a chopper, skip to the fabrication chapters first. Come back to the scooter motor controllers later. Bike- Scooter- and Chopper Projects for the Evil Genius.pdf
Final pro-tip: Once you have the PDF, go to Page 67 first. Look at the "Plywood Jig for Frame Alignment." That single diagram will save you more frustration than the rest of the book combined. The book was written when steel was cheap