MRBoston

I' have recently done a basic refurb on my 1977 Nishiki Olympic, after decades of not riding, and in the process, decided I would do some dimensional documentation and perhaps create a CAD model of the bike for future reference. Whether that project has any real merit is another question entirely, but in getting the bike road- and ride-worthy, I did some basic measuring of various locating points, and became curious about a couple of things:

1. Whether there is easily accessible general frame design information, such as "normal" range of angular dimension relationships of frame tubes, and
2. Where I might find a good layout drawing and/or associated information defining/naming the various parts of a typical road bike frame.

I was not in any way curious about this sort of stuff when I bought the bike originally, but was simply interested in getting transport for work commuting in Boston and getting around without car, so I'm playing a little catch-up here.
My curiosity was sharpened after I had created a hand sketch and started the CAD model, using an eyeballed 75-degree value for the seat tube-to-crank bearing housing, then saw some discussion on this forum that contained several references to 76 degrees for what I recall as a few different frames. That made me wonder about "standard" design dims.
If anyone has pointers for basic info, that would be appreciated. Thanks --

unterhausen

Standard seat tube and head tube angles are both 73 degrees (because that's what I like). 72 degrees is also common. I would expect most road bikes to be somewhere between 68 and 75 degrees. One source of this information is manufacturer websites.

I don't know if you can get a free version of rattlecad at this time. There are demo versions of bikecad https://bikecad.ca/bikecadpro (at the bottom). Not sure what the limitations are, it might work for you.

Andrew R Stewart 

Pre interweb we viewed the CONI book and Sutherland's Manual as the defining texts on this. Andy

JohnDThompson 

Martin Manning wrote an Excel spreadsheet for frame geometry (also works in LibreOffice and gnumeric). It hasn't been updated for a while, but is still relevant.
XLS file: https://docs.google.com/spreadsheets...f=true&sd=true
Documentation: https://docs.google.com/spreadsheets...f=true&sd=true

MRBoston

Thanks for the pointers. The Sutherland's Handbook looks especially useful. I'm sure I'll have some more questions at some point. Any additional recommendations accepted with gratitude.

79pmooney

I'd be interested in seeing the angles on the Olympic. I raced a '76 Fuji Pro. 74 seat, 75 head. 59 cm seat tube. Roughly the same top tube. Chainstays as short as you can do and still get an inflated training tubular in. (With a little muscle; race Criterium Setas went in just fine. You could only insert your fingers between seat stay and tire once. NOT recommended!)

guy153

https://geometrygeeks.bike/ is a good resource.