Is there a resource, online or off that explains the frame angles and tube lengths and the effect they have on each other. In essence why is a frame built the way it is to give a certain effect. Also, what effect changing the measurments has. Thanks.

Here's one general article to start with, https://sheldonbrown.com/frame-sizing.html The links at the bottom of the page may explain more.

Here's another relevent article, https://www.anvilbikes.com/?news_ID=49&catID=3

Regards, Anthony

You will find that seat and head tube angles pretty much will all be within the narrow range of 72 to 74 degrees and will vary even between the sizes of a given model. About the only generalities that I know of is that a more race-oriented bike usually has a steeper--e.g., 73-74 degree--headtube angle and shorter wheelbase (and so, a shorter chainstay length, which sort of dictates a steeper seattube angle. A more comfort-oriented bike oftentimes will have a little longer wheelbase so a more relaxed--e.g., 72-73 degree--seattube angle is possible because a longer chainstay length is not a problem (and may be desirable for larger tires and a wider gear range).

Anthony - Thanks.