[python] Re: FWD/RWS tadpole

Super! This is what I need! I am already looking forward to winter ;-D

(a dymaxion search brings up some interteresting pages)

It is interesting to hear there is no speed problem!

It is an interesting observation that they use a complete vertical
setup, so they can change tire sizing without effect on the trail. And
yes, with a spring you can create more or less the same effect as with
the self centering effect (quadratic in potential energy).

Do you think it would be possible to have the derailleur hub directly
connected to the two front wheels (i.e. have a axle going between the
two wheels going through the hub. Possibly have two free wheels on each
side of the hub as a differential?

Dirk

25hz wrote:
> Bingo . . .
> Here:
> http://www.ihpva.org/pipermail/trikes/2006-January/041612.html
> and here:
> http://www.ihpva.org/pipermail/trikes/2006-January/041629.html
> http://www.greenspeed.com.au/tyabb.jpg
>
>
>
>   
>> That trike link is pretty cool.  It looks like the Christiania trikes, but
>> the rear steer would really make them maneuverable.  The FWD/RWS tadpole
>> that was built by Ian Sims (Greenspeed), according to him, was fast, easy
>>     
> to
>   
>> control and they actually raced it successfully.  I still can't find a
>> picture of it but the steering was based on the Dymaxion.  Paul said that
>> the trick to rear wheel steer is to have the pivot aboslutely vertical
>>     
> with
>   
>> ZERO trail.  While zero trail produces no steering "feel" or "weight" they
>> fixed that by adding springs to the steering linkage so the rear wheel had
>> some artifical "weight" to the steering inputs and it would also
>>     
> self-center
>   
>> then.  If I remember correctly, they didn't use a steering damper because
>> with zero trail, there was no tendency for the rear steering wheel to
>>     
> shimmy
>   
>> to one direction or the other.  It was also only one wheel drive to the
>>     
> left
>   
>> front wheel.
>>
>>
>>     
>>> Oh never heard of sidewinder! Thanks! I am _considering_ building a
>>> tadpole ... and FWD/RWS seems to be ideal -- if the speed problem can be
>>> solved. I knew actually of a rear steered tadpole before, but upright.
>>> Here it is:
>>>
>>>     http://www.sortejernhest.dk/christiania-cykel/index.jsp
>>>
>>> You see it quite often in copenhagen. They use a steering damper, may be
>>> exactly to take away oscilations from riding at speed.
>>>
>>> Dirk
>>>       
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