A very good book for scratch builders and designers everything from basics to advanced. Its an older book but the info is still valid today. R/C Model Aircraft Design by Andy Lennon on line downloads as a PDF file. You can scroll through the whole book online at
http://www.scribd.com/doc/55837270/R...-Design#scribd Chapter 25 page 125 shows basic proportions for both trike and taildragger gear.