Yes. All of that. Working with known dimensions - wheel base, wheel diameters, seat height, stock dimensions of some components like the fork and brake disks it's "easy to set up those items in rough form. The bike in stock form has plenty of references, so just scale images to suite the rough 3D and use that as a basis for rough forms, then "simply refine them working from visual references. Working all areas at once helps keep everything in proper proportion. There's nothing worse than spending hours making a part only to find out it's too wide or too long or doesn't clear the frame.
Thank you very much for the reply and the explanation. I've been getting into rhino and solid works on basic shapes and forms but the details get me every time with self intersecting surfaces errors of one kind or another. I just need more patience and practice. The online youtube tutorials are great but very generic. Are there there better resources/classes for more detailed work? Thanks again for replying, I'm looking forward to seeing more of your work!