[python] another newcomer

Dear pythoniacs
I just shortly want to introduce myself. My name is Thomas and I live in Copenhagen. I learned the python to know via Dirk, when he built his baby and helped building several of them in our kvisten club in København. I must say, that I was immediately impressed by the construction and basic idea. Yesterday I read a thread in a lowracer forum, discussing the issue that riding a lowracer can be embarrassing for some people. And I somehow know this feeling. But the python seems different. The rider doesn't look so clumsy on the bike. Maybe riding the python requires that you are relaxed. And here I have to stop talking, because I have never tried it myself. Not yet.
It was just recently that I found the mailing list through a search in the Internet. And first of all I have to express my respect. Your projects and in particular Jürgen's page with all the various measures on the python survey and links to the original sites is very useful.
I also noticed that just recently, this mailing list has been exploding. Okay, it is a www. But anyway, compared to the very first start, this list has certainly attracted a lot of attention. And now I am just one of the many many readers to say hello. Anyway, I guess, that was part of the purpose by establishing this platform. And I hope it will continue.
So, obviously I am soon going to build my python. And I have prepared a number of things. I collected something like 5 donor bikes. Should be a fair starting point. I am about to make the wheels. In 20''. The overall goal of the project will be to use as many bike parts as possible. I figured that it will be fairly easy without being too picky on the source material to make front parts from racing-bike back part and back parts from MTB forks. So the main challenge will be in the construction of the middle part. And just here, there is, as you know, as many solutions as there are constructors. 

Maybe you could help me in a few questions:
What is the significance of the BB/seat difference? Does it have any impact on stability / centering? Or is it more about the comfort and related to the seat angle? In principle, 20'' wheels would allow the BB to be lower than the seat. I have not been able to find such examples. But the values in Jürgen's project survey rank from 5 to 29,5 cm.
I am considering a construction, where the pivot angle is adjustable. At the same time, it could also be linked to shock absorption. In that way, it will have to be adjusted to the weight of the rider to have a kind of resting position. But the pivot angle will then still (again depending on the features of the shock absorber - should certainly be rather stiff) be under constant change. Compressing the absorber would reduce the pivot angle and consequently the negative trail and vice versa. Has anybody experience with that? Would that kick the rider off the bike? Do you have any idea how this would affect stirring dynamics? Or shall I make the test? J
The last question for now: The wheels base! I understand that the wheelbase will influence the self-centering effect. But apparently much less than the pivot angle. So, is there any limit for the wheelbase in any direction? And why?
I hope, you still have the power to answer the many questions of all these newcomers. 

Cheers
Thomas

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