[python] Re: Questions from a total newbie

Hello Jurgen, thanks for your response.

Jürgen Mages wrote:

Weight sure makes a difference. My experience with 25 kg
more luggage on tour: I noticed better downhill stability and
a wider turning circle.


Cool, finally a bike on which being heavy is an advantage :)

The pivot made of tapered roller or
angular contact ball bearings is clearly superior to the BB
solution, regarding endurance, weight and ground clearance.

That's what I thought. I'll probably use conical needle bearings. I wouldn't feel comfortable with a BB loaded radially, or a conventional bicycle headset with that much trail.

I never tried small wheels, but the experience of Dirk seems to
prove that.

Neat, I think I have a 20" wheel with a dualdrive hub somewhere in my parts bin. That's a keeper.

By moving the CoG backwards the traction of the front wheel
is reduced. Also the self-centering should be best if the CoG
is right above the steering pivot.

Actually, I was thinking of moving the rear wheel back and keeping the rider atop the steering pivot, thus moving the CoG forward. This would also free up some space behind the seat to carry stuff (did I mention that I wanted to make it a touring bike?). Sounds like the placement of the rear wheel isn't all that important though, and there's always the possibility of making a rear frame that can be stretched since the rear is very simple.

Maybe you know the experiments of Andreas Leutz with his airbike
and flevobike or the Yellow Submachine of Uwe Carstens.
Both can vary the seat height and the pivot angle while riding.

Well, what I had in mind is a bike where the seat height is constant, only the angle of the main pivot would change. This would involve mounting each half of the pivot bracket (front and rear) on a horizontal pin and controlling their angles together with regard to their respective halves of the frame with set screws, so that the bike's overall geometry wouldn't change. Being my first Python, on one hand you're right, I should keep it simple, but on the other hand, if I implemented something like that (if it's doable at all), I would have room to experiment with the pivot angle without having to make another frame each time.

I'll whip up something in Autocad when I have some time and I'll post it here to show you what I mean exactly. It needn't be very complicated, it just needs to be designed properly.

Thanks a lot for your feedback, I appreciate.
Take care!

--
Pierre

============================================================

This is the Python Mailinglist

http://www.freelists.org/list/python

Listmaster: Jürgen Mages jmages@xxxxxx

To unsubscribe send an empty mail to python-request@xxxxxxxxxxxxx
with 'unsubscribe' in the subject field.

============================================================

Other related posts: