[python] Pythonjetrike update

  • From: Patrick van Gompel <patrick_van_gompel@xxxxxxxxxxx>
  • To: <python@xxxxxxxxxxxxx>
  • Date: Tue, 31 Jan 2012 14:17:55 +0100

Just a little update about how the pythonjetrike is holding together.

A few months ago I made a new rocker arm. The old one was deformed by the heavy 
load and the angle was too sharp, so the new one is stronger, straighter, 
without the attached handle bar and has bigger rod ends. 

I changed the attachment points for the ropes (that go from rocker arm to swing 
arm). http://cycle.free-creativity.com/images/attachpoint1.jpg
It is still a dual rope (a looped rope around the attachment point and another 
safety loop through a simple hole). The new attachment point is a milled piece 
of stainless steel that holds the rope better than a simple bolt. 
http://cycle.free-creativity.com/images/attachpoint2.jpg  And it has some tiny 
holes in it for a safety wire (green) so that the rope can't be detached by 
After 1000+km the rope does show signs of wear, but nothing to be afraid of. 
http://cycle.free-creativity.com/images/ropewear.jpg  The green coloured woven 
pattern is just the outer layer of the rope. The inner part of the rope isn't 
showing through, so the rope should be still ok. I just slided the rope a bit 
further around the attachment point and it is ready for another 1000km. A dust 
cap would certainly help to keep the sand out and prevent quite a bit of wear, 
but since a rope is cheap and holds pretty long, I don't think I will bother 
about it.
The use of a simple and cheap rope is the best idea I got from this Python 
list. Thank you very much again!

Yesterday we had the first snow of the year. I went out with the pythonjetrike 
in the evening when there was a 1cm layer of snow with more comming down. Since 
the snow was fresh, it wasn't that slippery. Quick acceleration was causing the 
frontwheel to slip and the same with heavy braking. Control was great although 
I didn't go for high speed cornering (20+km/h). When I went home, at some 
places the snow was slippery (driven over by cars). To get going was quite a 
challenge at those places, but when accelerating very gently is was doable. 
Braking was a problem and loosing control was something to worry about. Though, 
when the pythonjetrike was rolling at a constant speed (up to 25km/h), it 
seemed rather stable. Cornering was ok and there was no tendency to slip into 
it's own direction. It seems that a frontwheel driven trike and the low CoG 
does have it's advantages in snow. I might try a snow tire in the future, but 
not before I switched to 24".
Though, I somehow have not such good experiences with muddy surfaces. When I 
was cycling together with a Strada velomobiel, my sideway movement in muddy 
terrain seemed to be about double compared to this rearwheel driven trike. And 
I was more afraid of loosing control (but that might also have to do with the 
higher speeds ).


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