Originally Posted by
sloar
Very well put Tom, but I was a slacker in high school and didn't take Trig. I guess thats why I ended up in the military instead of college. Very interesting thread though, thanks for the input. Math was always my weak subject and now I'm going through it with my oldest daughter. My youngest takes after my wife who took Trig in junior high.
You don't have to know trig, only that it exists. Then it's a matter of blocking out the issue on paper or in your mind.
This is simple if you open your mind to it. Imaging the bike supported on the two wheels separated by the wheel base, say 38" (965mm) or so. Now one end drops by 7mm. You can now imaging a narrow triangle formed by the original line and the new one dropped at one end.
So, in considering the effect, one of the questions is what kind of change to the frames geometry happens, specifically to the head and seat angles. This is where the trig come in, and fortunately, all that work is done already, and if you can frame the question, you'll get the answer on the internet.
In any case, this isn't about showing off, it's simply an attempt to quantify the effect so the OP has a basis to consider the possible effect on the bike.
BTW - there's a certain irony here, if you don't mind me pointing it out. Folks here on BF often talk about all the tools they own, and the importance of using the right tool. Well, a basic understanding of math (very basic) is also a tool, and is the right tool for questions like then OP's.