[python] Re: python Digest V7 #63

  • From: Rhisiart Gwilym <Rhisiart@xxxxxxxxxxxxxx>
  • To: python@xxxxxxxxxxxxx
  • Date: Mon, 2 Nov 2009 07:49:56 +0000

Hello Erik!

I put onto my bike the same rear-suspension which Jurgen originally invented for P1. I always liked the cheap, simple effectiveness of it, and mine works well too. It cost me literally nothing at all beyond a few hours construction work.

Loath to lose it, having once made it, I'm now aiming to retain it in the linkage to my trike back end.

Of course, that involves some thought about how to prevent the transverse rotational shocks from the two separate back wheels, when hitting bumps independently, wrenching at the front swing-arm bolt and its seating (on the rear suspension assembly), which would likely cause it to become badly worn very quickly, or even to break eventually.

After some meditation in the Drawing Office of the Mind (the only one I keep these days) I think I have a solution, in the 'simple-but-robust-and-workable' Mages tradition of bike-building. But instead of trying to describe that in words, I'll post photos -- and a vid -- as soon as I have something respectable to show.

I'm definitely aiming to keep the bike back end though, of course. Even after I have the trike back end running for everyday use, I shan't rest easy until I've cracked the knack of riding the bike form fluently. I'll follow the little-by-little approach that most new riders seem to have had to use. Serge just described his experiences to me yesterday in learning to ride his beautiful Python bike.

But how is it that SOME riders and some Pythons just seem to hit it off so well that they can ride almost at the first try? Dave was riding his Cherry Bomb pretty fluently within half an hour, and there's that young guy in the video that I posted a few days back in reply to Jurgen. Ten minutes to find the knack, he said.

I've been wondering if this might be something to do with some builders just happening to hit on a subtle mix of the basic Python geometry which just makes them easier to ride. There seem to be one or two stories in the Python saga so far where riders find surprising differences between difficult and easy Pythons, when they get to ride several different ones. Seeing that we all build our own, there being no manufacturer who makes a standardised version to sell, they're all slightly different. That's a very fruitful situation. But I can't work out at all what makes a sweet, easy-ride Python, and what makes a Bramah bull that throws you off in a few seconds. (I seem to have a Bramah!) Anyone on the list have any insights into what makes a sweetie?

Anyway, sweetie or Bramah, I'll ride my bike properly in the end. I have several pairs of welding gloves to choose from, Erik. And maybe, after you AND Serge mentioning it, I'll get the skate-boarders' elbow protection too. But this week, trikes rule OK, till I have it up and running. Pix soon.

Thanks again to all for the encouragement. Without the trail-blazing, and now the support, of the listees I reckon I would have abandoned this whole thing some time back as a big mistake that lead nowhere. How wrong would I have been!

Hwyl fawr i bawb,   Rh

Pythonaut trials with body armor.
I use very big and thick welding gloves and skateboarder elbow protectors, cause at 65 I injure easily and recover slowly. But trike is not a bad idea. Has anybody tried to add suspension in the rear triangle (say 2 mountain bike style springs in each strut)?
Erik Vandamme
54 Hilltop Road - WAMBERAL NSW 2260 Australia
<mailto:erik1vandamme@xxxxxxxxx>erik1vandamme@xxxxxxxxx
Skype - erik_vandamme


FreeLists Mailing List Manager wrote:

python Digest   Fri, 30 Oct 2009        Volume: 07  Issue: 063

In This Issue:
                [python] Re: Query about weight distribution
                [python] Re: Query about weight distribution

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Date: Fri, 30 Oct 2009 15:16:16 +0800
Subject: [python] Re: Query about weight distribution
From: jinlin wen <mailto:jinlwen@xxxxxxxxx><jinlwen@xxxxxxxxx>

Dear Mr. Rhisiart Gwilym:
I am seventy now and had the same experience as you had. Although I really
admire the python riders,I gave up practicing anyway. I am riding my python
trike for two years now. I like it much. I think the geometry of my trike is
ok. I have gone through all different road surface and all weather. I
climbed quit steep hills. The traction was enough. It is an enjoyment riding
on ice because the surface is very smooth!

Jinlin Wen

2009/10/29 Rhisiart Gwilym <mailto:Rhisiart@xxxxxxxxxxxxxx><Rhisiart@xxxxxxxxxxxxxx>



Hi Pythonauts!

This bruised and strained learner-rider needs a bit of advice.

My learning-curve on my Python bike is going pretty much as other
Pythonauts have described their first attempts to ride. But I have a small
problem. It's called 'old age': Every time that I fall off, or when I'm
pushing wildly with my stretched fingertips against the ground to prevent an
imminent fall, I seem to bruise or strain something. (Can scarcely type this
morning because of a strained right hand)

I guess it doesn't happen so easily to younger, more elastic bodies. Nor do
the resulting minor injuries take so long to get painless, then heal. ('I
was that way once myself', he mused sadly....)

So -- ruefully -- I think that I have to bring forward the trike back-end
for my Python, which I planned to build anyway, as an alternate for the
single-wheel back-end. As well as avoiding the slightly worrying build up of
little bodily problems from trying to stay on my Python for more than thirty
metres (the struggle is also AMAZINGLY hard work; I'm sweating and panting
within a minute or two of starting a practice session) I'm also concerned
that it's going to take me a long time to get fluent enough at riding the
bike to be able to go on the road in traffic. But I want to be able to use
my Python this Winter, rather than my conventional bike. I keep no car, and
I ride right through the year, as my main form of personal transport, but I
had a couple of near-miss worrying incidents last Winter with my standard
bike on icy roads.

Besides this, I've designed into my version of the Python front end
provision to be able to put a minimal all-weather John-Tetz-style zote-foam
fairing onto it, or a fitted spandex cape at least, so that I can ride in
heavy rain. Done a few lash-up experiments with this already, and I'm pretty
confident that it'll work, even in gusty cross-winds.

So, everything seems to be pointing towards a trike set-up, at least until
I'm fluent enough with my Python-steering reflexes.

That leads me to ask for some advice: I notice that some trikes have their
back wheels set behind the rider's seat, whilst some have them set well
forward, almost level with the rider. So how does the placing of the back
wheels affect the percentage of the overall weight carried by the
front-wheel -- **and how, therefore, is the crucial traction on
wet/steep/gravelly surfaces affected?** This is my key question.

My Python, like my other bikes, will have to be a serious work-horse, able
to carry freight, and able to handle any weather conditions and any surface,
on or off road. I notice that Henk's trike is a serious load-carrier, and
Wen's seems to be pretty good too, and snow-capable.

Any advice/experience from other Pythonauts about the best way to design my
trike back end for this spec. is very welcome.

I should say too that, despite being in the thick of ironing out the
wrinkles at the moment, I really LOVE this bike, even though I can't stay on
it yet. I can see it becoming my number one personal transport rig
hereafter. Once again: thanks and respect, Jurgen, for the trail-blazing.
Plenty of times the past few days I might have thought: 'I've made a big
mistake here. This bike isn't rideable,' if I didn't know -- from the videos
and the listees' accounts of their early adventures -- that that's not so.
With that vital knowledge, I persisted, and already I can see progress in
staying balanced and moving forward. But bloody hell I'm all bruises and
strains, even though I've been practising on short, soft turf.

Diolch yn fawr/danke schon/many thanks for all advice,   Rhisiart G
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------------------------------

Date: Fri, 30 Oct 2009 13:03:07 +0000
From: Rhisiart Gwilym <mailto:Rhisiart@xxxxxxxxxxxxxx><Rhisiart@xxxxxxxxxxxxxx>
Subject: [python] Re: Query about weight distribution

Hi Jurgen, and greetings to Wen and George also.
Damn, that rider in the vid is good. Why can't I ride like that!

Other related videos offered beside that one led me to this too:

<http://www.youtube.com/watch?v=659J7qLFquE&feature=related>http://www.youtube.com/watch?v=659J7qLFquE&feature=related

I've felt that I've been within an ace myself of getting that 'click'
he mentions, in some of my most recent practice rides. Maybe I should
persist with the bike set-up a little longer(my strained hand is
better this morning)......

Many thanks for all the offered useful knowledge. I'm still wavering,
though: should I go for the complete trike back end, or simply put a
couple of stabilisers on my bike, just like a little child's first
bike, and carry on trying to reach that click point?

I'm tempted to say that I should stick with Wen and the other older
Pythonauts. I'm only a year behind you, Wen, so -- SOLIDARITY BROTHER!

But still, it would be nice to get to the breakthrough, and achieve
that fluent ease of riding, like the young guy in the vid above, or
like Jurgen doing eight-turns in that video on the Python website.
Damn!  What do I do......?

Thanks again to all for the advice.

Hwyl fawr,  RhG


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End of python Digest V7 #63
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