How Do I Design A Frame?There are many considerations that go into designing a frame, far more than can be answered here. First, of course, is the rider: a custom frame will be designed around your particular leg length, torso length, arm length, and preferred riding position. Then there is the intended use of the bike: do you want a fast-handling crit bike, or a loaded touring bike that handles smoothly descending the Alps with 50 lbs. of gear? What diameter of wheels and width of tires do you want to use? Do you need fender clearance? What size are your shoes? (Seriously: shoe size affects toe clip clearance in front and chainstay and pannier clearances in back. If you will be touring in mountain bike shoes or even boots, you may need more room than if you stick to sleek road riding shoes.) For an amateur, a great introduction to the design and construction
of a lugged steel bicycle frame is Richard Talbot's aptly named
Designing and Building Your Own Frameset: An Illustrated Guide for the
Amateur Bicycle Builder
published by the Manet Guild. This book
is out of print, but if you don't mind paying a premium price, you can usually
find a copy through a used book search like
Alibris Talbot discusses both theory and practice of building a lugged steel road frame, including building your own jigs. The emphasis is on hand labor, not machine tools -- he assumes you will miter your tube joints by hand with files and scrapers, not stick the tubes in a milling machine. There's an introduction to brazing and materials, too, though it's specifically *not* a beginner's guide to brazing -- Talbot suggests looking for a local vocational school to learn how to braze, since practice is essential. The design considerations apply no matter what construction method you plan to use, so this is still a useful book for the welders out there. Here's a picture of a very simple frame jig made from plywood and angle iron, similar to what Talbot describes. This is what I built my first frame on, and it came out within a millimeter of perfectly aligned. Fancy production jigs make changing the jig setup quick and easy, but they really aren't needed for do-it-yourself scale production. Soon I hope to add some other jig photos with more details. The Paterek Manual by Tim Paterek is a much more detailed manual for professional frame builders, but is also much more expensive, $65 or more. I'd suggest looking at your local library for it; I know the King County, Washington library system has a copy, though it is an older edition and you may have to wait. Paterek goes into greater detail in discussing the steps of designing and building a bike, and provides a step-by-step checklist suitable for a beginning commercial builder who wants to be sure nothing is left out along the way. There are also many designs for building your own jigs and other tools, in case you want more sophisticated equipment than Talbot's wooden jgs, but don't want to pay $2,000 or more for commercial gear. Besides the wealth of information on proper design, current editions of the Manual include references on fillet brazing and TIG welding. The latest edition includes many hand-written margin notes by the author, reflecting the decade of changes since the Manual was written. Paterek also provides an updated list of sources for tools, bicycle parts, and other useful supplies. The design principles in the Manual are also incorporated into Paterek's frame design software, which not only performs the needed calculations but generates working drawings on HP-compatible plotters. Paterek's Manual is published by, and available from: Henry James Bicycles, Inc.704 Elvira Ave. Redondo Beach, CA 90277 310/540-1552 (Henry James is a good source for more than just books, by the way. His main business is making and selling beautiful cast lugs, fork crowns, and bottom brackets in both CrMo and stainless steel. He also stocks brazing supplies, his own beautiful, well-thought-out frame and fork jigs, and Tim Paterek's two-part video on fillet brazing. If you're seriously interested in building a bike, order Talbot's book from Henry James and ask for a price list, too. He doesn't take plastic, but will ship COD.) Other Good References on Frame Design and Bike FitWhile Talbot and Paterek both tell you how to design a frame, there are many ways of sizing a frame to fit a particular person, and no one way can be taken as gospel. The following are good references for bike fit, though most do not directly address actually designing a frame.
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