"MINI-PYTHON" thought

I like very much the center steering bent concept with front wheel drive (I already have a FlevoRacer) and the idea of the self centering due to the rider's weight is really interesting!
Hera after some CAD 3D pictures of possible rear frame solutions for a
"mini-python" concept recumbent.

V.I.L - Very Important Links
Jurgen Mages's "Python"
Dirk Bonne "Mini-Python"
Marc's Python
Mike's Python
Serge's Python
(interesting bird-cage frame)
Olaf Johansson's "Monty"
31/01/2006
SOLUTION n.1 - name:" bird-cage-01_low"

wheel size = 20 [inch]
wheelbase = 1100 [mm]
pivot angle = 60 [deg]
trail = -160 [mm]
seat height = 330 [mm]
n. of parts for the frame = 20
seat + frame weight = 4.5 [kg]

 First attempt to follow the "bird-cage" approach like Dirk Bonne's "mini-python2":
-- too many parts for the frame
-- seat too low
++ looks really cool !
SOLUTION n.2 - name: "bird-cage-02_medium"

wheel size = 20 [inch]
wheelbase = 160 [mm]
pivot angle = 60 [deg]
trail = -160 [mm]
seat height = 415 [mm]
n. of parts for the frame = 20
seat + frame weight = 4.6 [kg]

 Second attempt to follow the "bird-cage" approach like Dirk Bonne's "mini-python2":
-- too many parts for the frame
- seat still too low
+ looks a little bit less cool
SOLUTION n.3 - name: "quadro-01_medium"
wheel size = 20 [inch]
wheelbase = 1100 [mm]
pivot angle = 60 [deg]
trail = -140 [mm]
seat height = 440 [mm]
n. of parts for the frame = 9
seat + frame weight = 4.4 [kg]

Different approach with the goal to riduce the number of parts::
++ simple rear frame
+ seat high enough
+ lean look

This third solution seems to be the more promising.
SOLUTION n.4 - name: "mini-phyton_piastra-01"
wheel size = 20 [inch]
wheelbase = 1100 [mm]
pivot angle = 60 [deg]
trail = -140 [mm]
seat height = 440 [mm]
n. of parts for the frame = 9
seat + frame weight > 5 [kg]		 The idea behind this solution is to avoid a welded frame using two aluminum plates laser cutted.
The final result is too heavy ... may be a solution to take in account for a "very-low-racer".
SOLUTION n.5 - name: "mini-phyton_integrale-01"
wheel size = 20 [inch]
wheelbase = 1100 [mm]
pivot angle = 60 [deg]
trail = -140 [mm]
seat height = 440 [mm]
n. of parts for the frame = 9
seat + frame weight = 3.8[kg]
without the rear fork

The idea behind this solution is to have seat and frame as an "one piece" structure.
This solution has to be deeply investigate ... and the final result could be not so far from the vk3 model by Velokraft with rear suspension.
But considering as an example the weight of the rear fork of my FlevoRacer (1.4 kg), a weight comparable withe those of the previous solutions could be of 5.2 [kg]: too heavy!