Hello Pierre!
Congratulations for the successful (and fast) build.
As far as my opinion goes, I would recommend two changes to your design:
1) Move the seat further forward so that the steering axis goes through your
hips. That improves the turning angle because rear part of front tyre doesn't
collide with your thighs, and also allows the second point to be done:
2) Move the bottom bracket lower. From the aerodynamic point of view, you want
to hide behind your "pedalbox", so your feet and knees shouldn't stick above
your shoulders or below your underseat handlebars. From the ergonomic point of
view, leg muscles work better when they are lower and blood pressure in them is
higher, but that may be individual. And it's easier to put a foot on the ground
if the pedals are lower. From the stability point of view, lowering centre of
gravity of the front fork decreases wheel flop.
For the steering pivot, cartridge bottom bracket and 12 mm rod end bearings
seem to be the most popular solutions. The former for its reliability and no
maintenance, the latter for ease of construction. No fatigue problems I know of.
Regards
Mirek
______________________________________________________________
Od: "Pierre Eyben" <pierre.eyben@xxxxxxxxx>============================================================
Komu: python@xxxxxxxxxxxxx
Datum: 10.03.2020 07:42
Předmět: [python] Fresh Pythoon enthousiasts
Hi Pythoners !
We're a small team of Python Recumbent Bike enthusiasts, and we recently
built a first prototype from an old racing bike to try out and learn to
ride the beast. It's was a clumsy first bike which was built in just one
afternoon.
[image: IMG-20200309-WA0010.jpg]
Nevertheless we tried it out and it went very well for some - after trying
it out twice, my brother could ride the bike like if he always did- and
much worse for others, like me...
We plan to built some more after handling the bike and set a trip to Cape
North next year on those bikes.
Before building final versions we are eager to ride it and gather as much
information and feedback as possible.
Could you give us some of your own experience about the different
parameters and ease of ride or advice for longer trips?
Some parameters we think are interesting are
- good climbing (probably by having weight on front wheel)
- 26" wheels (quite universal, easy to repair)
- weight : keep as low as possible
- material: steel and plywood (maybe high alloy ?)
Besides this, i'm wondering which is the best type of bearing for the pivot
rgearding fatigue ?
Looking forward reading you and thank you in advance for your reply !
Best regards,
*Pierre Eyben*
Ingénieur Architecte
Rue A. Dansaert 192
1000 Bruxelles
+32 (0) 488 91 07 01