[python] Re: python Digest V9 #118
- From: Howard Stevens <hstevens94@xxxxxxxxx>
- To: python@xxxxxxxxxxxxx
- Date: Tue, 2 Aug 2011 22:22:33 +1000
Hullo Python trikologists,
I have been following your discussion with interest but as yet have not had
the opportunity to test my trike out much, only doing a few rides around the
district.
There are a couple of points I would like to make however, and wonder if
others are finding the same results.
# My python trike definitely has a "sweet spot" around the 52degree of pivot
angle. I had a lot of PSI problems at 62 degrees, but reducing the angle
now gives me comfortable, direct steering with minimal PSI. The Hippiron
trike also had a similar angle. Are others finding that trikes are
different to bikes in this regard?
# I wouldn't bother with rear brakes and find that the single front disc
brake is excellent, and pulls me up with quite a jolt.
# I find turning is a bit uncomfortable at speed and requires some leaning,
but then I am a sedate grey nomad, in no particular rush!
All the best Howard Stevens
On Tue, Aug 2, 2011 at 3:07 PM, FreeLists Mailing List Manager <
ecartis@xxxxxxxxxxxxx> wrote:
> python Digest Mon, 01 Aug 2011 Volume: 09 Issue: 118
>
> In This Issue:
> [python] Re: AW: Re: Questions about Python-Trike geometry (
> [python] Re: AW: Re: Questions about Python-Trike geometry (
> [python] Re: AW: Re: Questions about Python-Trike geometry (
> [python] Re: AW: Re: Questions about Python-Trike geometry (
>
> ----------------------------------------------------------------------
>
> From: Patrick van Gompel <patrick_van_gompel@xxxxxxxxxxx>
> Subject: [python] Re: AW: Re: Questions about Python-Trike geometry
> (project si
> Date: Mon, 1 Aug 2011 15:12:34 +0200
>
> Ah, thanks for your explanation! Yes, having just rear brakes on a trike is
> not a good idea. A front brake will make all the difference.
>
> I can't help you with the geometries, as I haven't tried (many) different
> setups.
> My 'magic moment' was there when I temporarily attached two wheelchair
> wheels on my Python. Although the construction was weak and the track was
> too small, it did give me a sudden insight of how the Python was steered. On
> this trike the cycling was very easy. It appeared to me that steering wasn't
> the actual problem, but keeping balance was. That might sound like an open
> door, but when you steer on a Python your centre of gravity is actually
> shifted to the outside of the corner. That means that you have to lean more
> than on a conventional bike. I still have problems with that when I make
> sudden sharp corners.
>
> Thanks,
> Patrick
>
>
> > Date: Sun, 31 Jul 2011 21:34:39 +0100
> > To: python@xxxxxxxxxxxxx
> > From: Rhisiart@xxxxxxxxxxxxxx
> > Subject: [python] Re: AW: Re: Questions about Python-Trike geometry
> (project similar to Howard Stevens foldable Python trike)
> >
> > Hi Patrick,
> >
> > Well since I wrote, I've put the trike back-end back on my Python,
> > just to have another think about it.
> >
> > It rides really well, and I have literally instant control; had it
> > from the very first try out in fact, and went out on the road in
> > traffic that first day.
> >
> > So what I'm doing now is putting a brake on the front wheel (I hadn't
> > done that before) and I'm fixing a method to pull on both back brakes
> > by a single hand lever. I may also try two brakes on the front wheel,
> > operated by both hands, if the back brakes are just hopeless. I'll
> > report results.
> >
> > I must say too that being able to bank all of the trike, except the
> > rear-wheels frame, into bends, just like on the bike, is a real plus.
> > (Erik Wannee's training back-end photo shows you exactly the design
> > principle) It feels just like riding the bike, except that you have
> > those brawny handle-bars, fixed to the back end, to push down/pull up
> > on. I find that I do both at once when I feel myself going over. Just
> > like pushing frantically against the ground with your stretched
> > fingertips, but so powerful by comparison that you can stop all
> > fall-overs dead before they get going.
> >
> > And I've already noticed, even on my fairly short total time on the
> > banking trike that there is indeed a training effect for staying
> > balanced, so that you begin to be able to lift your hands slightly
> > off the bars for a few metres at a time. I suspect that with plenty
> > of use of the trike I should be able to ride the bike with
> > confidence, before long. You can see from the videos that there's a
> > knack; that first-time riders suddenly get it. That's the magic
> > moment that I'm shooting for!
> >
> > It does occur to me, though, that since we've all made our Pythons
> > ourselves, to no standard design, might it be that subtle, quite
> > small variations in bike geometry make all the difference between an
> > easy, sweet-riding bike where you get the knack easily and within
> > minutes, and a really tough dog? I seem to have made a tough dog.
> > Anyone got any ideas about that, based on experience with several
> > slightly differing geometries?
> >
> > Hwyl, Rh
> >
> > >Are you saying that you abandoned a beautifull trike design because
> > >of rear wheel skiding when braking? I want to build a python trike
> > >myself, so I wonder why you would worry about it. I mean, if just
> > >the front wheel is enough for braking, then why bother about the
> > >rear? My two wheel Python doesn't even have a rear brake. Or is it a
> > >safety concern? Though, you could always fit multiple brakes on just
> > >the front.
> > >Please let me know you thoughts,
> > >Patrick
> > >
> > ============================================================
> >
> > This is the Python Mailinglist
> >
> > //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.
> >
> > ============================================================
> >
>
>
> ------------------------------
>
> Date: Mon, 1 Aug 2011 07:16:28 -0700 (PDT)
> From: Vi Vuong <vi_vuong@xxxxxxxxx>
> Subject: [python] Re: AW: Re: Questions about Python-Trike geometry
> (project si
>
> Hi Rhisiart,
> Since our bike/trike experiments are quite similar, I would to suggest the
> following:
>
> 1. If pivot angle is higher than 60, find smaller wheels to try lower
> angles since you now have front brake. In my case, I went up from 48 deg...
> If there is a quick way to raise your seat, bring it as high as you can.
> Use sticks if you can't reach the ground.
>
> 2. Take off with fingers / sticks lightly resting on the ground (no
> leaning), and with as much pedaling force as you can without inducing steer
> (same trick to start with hands in the air). While training new riders, I
> obverse that they don't pedal hard enough and instead focus more on
> balancing and end up getting out of balance (I did the same but just
> couldn't see it). If you can "consciously" get some momentum going, your
> body/brain will amazingly take care of the rest... See my shaky
> and hesitant takeoff
> http://www.youtube.com/watch?v=6yBjSGL_pd8#start=0:00;end=0:07;autoreplay=true;showoptions=true
>
> 3. Once you learn to take off, you can take all the time you want with
> other riding aspects, and different configurations (levels of difficulty).
> Switching configurations / bikes can take a few minutes to adjust /
> relearn. However, be warned that you may get an itch to build more bikes...
> :)
>
> Have fun,
>
> Vi
>
>
>
> >________________________________
> >From: Rhisiart Gwilym <Rhisiart@xxxxxxxxxxxxxx>
> >To: python@xxxxxxxxxxxxx
> >Sent: Sunday, July 31, 2011 1:34 PM
> >Subject: [python] Re: AW: Re: Questions about Python-Trike geometry
> (project similar to Howard Stevens foldable Python trike)
> >
> >Hi Patrick,
> >
> >Well since I wrote, I've put the trike back-end back on my Python, just to
> have another think about it.
> >
> >It rides really well, and I have literally instant control; had it from
> the very first try out in fact, and went out on the road in traffic that
> first day.
> >
> >So what I'm doing now is putting a brake on the front wheel (I hadn't done
> that before) and I'm fixing a method to pull on both back brakes by a single
> hand lever. I may also try two brakes on the front wheel, operated by both
> hands, if the back brakes are just hopeless. I'll report results.
> >
> >I must say too that being able to bank all of the trike, except the
> rear-wheels frame, into bends, just like on the bike, is a real plus. (Erik
> Wannee's training back-end photo shows you exactly the design principle) It
> feels just like riding the bike, except that you have those brawny
> handle-bars, fixed to the back end, to push down/pull up on. I find that I
> do both at once when I feel myself going over. Just like pushing frantically
> against the ground with your stretched fingertips, but so powerful by
> comparison that you can stop all fall-overs dead before they get going.
> >
> >And I've already noticed, even on my fairly short total time on the
> banking trike that there is indeed a training effect for staying balanced,
> so that you begin to be able to lift your hands slightly off the bars for a
> few metres at a time. I suspect that with plenty of use of the trike I
> should be able to ride the bike with confidence, before long. You can see
> from the videos that there's a knack; that first-time riders suddenly get
> it. That's the magic moment that I'm shooting for!
> >
> >It does occur to me, though, that since we've all made our Pythons
> ourselves, to no standard design, might it be that subtle, quite small
> variations in bike geometry make all the difference between an easy,
> sweet-riding bike where you get the knack easily and within minutes, and a
> really tough dog? I seem to have made a tough dog. Anyone got any ideas
> about that, based on experience with several slightly differing geometries?
> >
> >Hwyl, Rh
> >
> >> Are you saying that you abandoned a beautifull trike design because of
> rear wheel skiding when braking? I want to build a python trike myself, so I
> wonder why you would worry about it. I mean, if just the front wheel is
> enough for braking, then why bother about the rear? My two wheel Python
> doesn't even have a rear brake. Or is it a safety concern? Though, you could
> always fit multiple brakes on just the front.
> >> Please let me know you thoughts,
> >> Patrick
> >>
> >============================================================
> >
> >This is the Python Mailinglist
> >
> >//www.freelists.org/list/python
> >
> >Listmaster: J端rgen Mages jmages@xxxxxx
> >
> >To unsubscribe send an empty mail to python-request@xxxxxxxxxxxxx
> >with 'unsubscribe' in the subject field.
> >
> >============================================================
> >
> >
> >
> >
>
> ------------------------------
>
> Date: Mon, 1 Aug 2011 21:48:49 +0100
> From: Rhisiart Gwilym <Rhisiart@xxxxxxxxxxxxxx>
> Subject: [python] Re: AW: Re: Questions about Python-Trike geometry
> (project si
>
> Many thanks, Vi. I'll take this on board and see
> what happens. Trouble with me is that I just keep
> falling over on the bike, and -- even on grass --
> after a while it just gets too painful and
> abrasive. Very exhausting too, for some reason.
> But I am encouraged by the slow sneaking up of
> the knack as I ride the trike and lift my hands
> just off the bars for ever-longer moments.
> Unlike your fantastic productivity, Vi, I'm very
> slow at getting things re-made. So I think my
> first line of attack is going to be to see
> whether I can learn to balance the tilting trike
> with the help of the fixed back-end, and then
> when I think that I've got it I'll put the bike
> back-end back on -- and see...
>
> Cheers all, Rh.
>
> >Hi Rhisiart,
> >
> >Since our bike/trike experiments are quite
> >similar, I would to suggest the following:
> >
> >1. If pivot angle is higher than 60, find
> >smaller wheels to try lower angles since you now
> >have front brake. In my case, I went up from 48
> >deg... If there is a quick way to raise your
> >seat, bring it as high as you can. Use sticks
> >if you can't reach the ground.
> >
> >2. Take off with fingers / sticks lightly
> >resting on the ground (no leaning), and with as
> >much pedaling force as you can without inducing
> >steer (same trick to start with hands in the
> >air). While training new riders, I obverse that
> >they don't pedal hard enough and instead focus
> >more on balancing and end up getting out of
> >balance (I did the same but just couldn't see
> >it). If you can "consciously" get some momentum
> >going, your body/brain will amazingly take care
> >of the rest... See my shaky
> >and hesitant takeoff <
> http://www.youtube.com/watch?v=6yBjSGL_pd8#start=0:00;end=0:07;autoreplay=true;showoptions=true
> >
> http://www.youtube.com/watch?v=6yBjSGL_pd8#start=0:00;end=0:07;autoreplay=true;showoptions=true
> >
> >3. Once you learn to take off, you can take all
> >the time you want with other riding aspects, and
> >different configurations (levels of difficulty).
> > Switching configurations / bikes can take a few
> >minutes to adjust / relearn. However, be warned
> >that you may get an itch to build more bikes...
> >:)
> >
> >Have fun,
> >
> >Vi
> >
> >
> >From: Rhisiart Gwilym <Rhisiart@xxxxxxxxxxxxxx>
> >To: python@xxxxxxxxxxxxx
> >Sent: Sunday, July 31, 2011 1:34 PM
> >Subject: [python] Re: AW: Re: Questions about
> >Python-Trike geometry (project similar to Howard
> >Stevens foldable Python trike)
> >
> >Hi Patrick,
> >
> >Well since I wrote, I've put the trike back-end
> >back on my Python, just to have another think
> >about it.
> >
> >It rides really well, and I have literally
> >instant control; had it from the very first try
> >out in fact, and went out on the road in traffic
> >that first day.
> >
> >So what I'm doing now is putting a brake on the
> >front wheel (I hadn't done that before) and I'm
> >fixing a method to pull on both back brakes by a
> >single hand lever. I may also try two brakes on
> >the front wheel, operated by both hands, if the
> >back brakes are just hopeless. I'll report
> >results.
> >
> >I must say too that being able to bank all of
> >the trike, except the rear-wheels frame, into
> >bends, just like on the bike, is a real plus.
> >(Erik Wannee's training back-end photo shows you
> >exactly the design principle) It feels just like
> >riding the bike, except that you have those
> >brawny handle-bars, fixed to the back end, to
> >push down/pull up on. I find that I do both at
> >once when I feel myself going over. Just like
> >pushing frantically against the ground with your
> >stretched fingertips, but so powerful by
> >comparison that you can stop all fall-overs dead
> >before they get going.
> >
> >And I've already noticed, even on my fairly
> >short total time on the banking trike that there
> >is indeed a training effect for staying
> >balanced, so that you begin to be able to lift
> >your hands slightly off the bars for a few
> >metres at a time. I suspect that with plenty of
> >use of the trike I should be able to ride the
> >bike with confidence, before long. You can see
> >from the videos that there's a knack; that
> >first-time riders suddenly get it. That's the
> >magic moment that I'm shooting for!
> >
> >It does occur to me, though, that since we've
> >all made our Pythons ourselves, to no standard
> >design, might it be that subtle, quite small
> >variations in bike geometry make all the
> >difference between an easy, sweet-riding bike
> >where you get the knack easily and within
> >minutes, and a really tough dog? I seem to have
> >made a tough dog. Anyone got any ideas about
> >that, based on experience with several slightly
> >differing geometries?
> >
> >Hwyl, Rh
> >
> >> Are you saying that you abandoned a beautifull
> >>trike design because of rear wheel skiding when
> >>braking? I want to build a python trike myself,
> >>so I wonder why you would worry about it. I
> >>mean, if just the front wheel is enough for
> >>braking, then why bother about the rear? My two
> >>wheel Python doesn't even have a rear brake. Or
> >>is it a safety concern? Though, you could
> >>always fit multiple brakes on just the front.
> >> Please let me know you thoughts,
> >> Patrick
> >>
> >============================================================
> >
> >This is the Python Mailinglist
> >
> ><//www.freelists.org/list/python>
> //www.freelists.org/list/python
> >
> >Listmaster: Jí[rgen Mages <mailto:jmages@xxxxxx>jmages@xxxxxx
> >
> >To unsubscribe send an empty mail to
> ><mailto:python-request@xxxxxxxxxxxxx>python-request@xxxxxxxxxxxxx
> >with 'unsubscribe' in the subject field.
> >
> >============================================================
>
>
> ------------------------------
>
> Date: Mon, 01 Aug 2011 22:57:43 +0200
> From: Gerald <bepb@xxxxxx>
> Subject: [python] Re: AW: Re: Questions about Python-Trike geometry
> (project si
>
> Hi,
> I made good experience with 48 degree pivot angle.
> Even more than with the two wheel configuration, the front brake is the
> most useful brake.
> Much more powerful because with the trike you don't risk falling if he
> front wheel slips.
>
> The rear brakes are not only much less effective, but also lead to
> unusual reactions of the bike if not applied symmetrical.
>
> Normally, one would expect that the bike will tend to the right if the
> right rear break is applied, but it is different with my python trike. I
> use the break on the right rear wheel, the impulse of the python trike
> is to go to the left. And the other way around.
> Actually the rear part turns to the right, but in this pushing the pivot
> to the right, which makes the front part of the bike turn left. This
> seem to get more pronounced if the track is more wide.
>
> Somehow having separate breaks for the left and right rear wheel - as I
> have on the trike - does not make much sense. And it is obviously only
> possible if you run a coaster brake on the front wheel.
>
> I include, an obviously outdated, picture of my python trike from last
> winter, showing the narrow track version:
>
>
>
> Gerald
>
>
>
>
>
>
> On 1.8.11 15:12 , Patrick van Gompel wrote:
> > Ah, thanks for your explanation! Yes, having just rear brakes on a
> > trike is not a good idea. A front brake will make all the difference.
> >
> > I can't help you with the geometries, as I haven't tried (many)
> > different setups.
> > My 'magic moment' was there when I temporarily attached two wheelchair
> > wheels on my Python. Although the construction was weak and the track
> > was too small, it did give me a sudden insight of how the Python was
> > steered. On this trike the cycling was very easy. It appeared to me
> > that steering wasn't the actual problem, but keeping balance was. That
> > might sound like an open door, but when you steer on a Python your
> > centre of gravity is actually shifted to the outside of the corner.
> > That means that you have to lean more than on a conventional bike. I
> > still have problems with that when I make sudden sharp corners.
> >
> > Thanks,
> > Patrick
> >
> >
> > > Date: Sun, 31 Jul 2011 21:34:39 +0100
> > > To: python@xxxxxxxxxxxxx
> > > From: Rhisiart@xxxxxxxxxxxxxx
> > > Subject: [python] Re: AW: Re: Questions about Python-Trike geometry
> > (project similar to Howard Stevens foldable Python trike)
> > >
> > > Hi Patrick,
> > >
> > > Well since I wrote, I've put the trike back-end back on my Python,
> > > just to have another think about it.
> > >
> > > It rides really well, and I have literally instant control; had it
> > > from the very first try out in fact, and went out on the road in
> > > traffic that first day.
> > >
> > > So what I'm doing now is putting a brake on the front wheel (I hadn't
> > > done that before) and I'm fixing a method to pull on both back brakes
> > > by a single hand lever. I may also try two brakes on the front wheel,
> > > operated by both hands, if the back brakes are just hopeless. I'll
> > > report results.
> > >
> > > I must say too that being able to bank all of the trike, except the
> > > rear-wheels frame, into bends, just like on the bike, is a real plus.
> > > (Erik Wannee's training back-end photo shows you exactly the design
> > > principle) It feels just like riding the bike, except that you have
> > > those brawny handle-bars, fixed to the back end, to push down/pull up
> > > on. I find that I do both at once when I feel myself going over. Just
> > > like pushing frantically against the ground with your stretched
> > > fingertips, but so powerful by comparison that you can stop all
> > > fall-overs dead before they get going.
> > >
> > > And I've already noticed, even on my fairly short total time on the
> > > banking trike that there is indeed a training effect for staying
> > > balanced, so that you begin to be able to lift your hands slightly
> > > off the bars for a few metres at a time. I suspect that with plenty
> > > of use of the trike I should be able to ride the bike with
> > > confidence, before long. You can see from the videos that there's a
> > > knack; that first-time riders suddenly get it. That's the magic
> > > moment that I'm shooting for!
> > >
> > > It does occur to me, though, that since we've all made our Pythons
> > > ourselves, to no standard design, might it be that subtle, quite
> > > small variations in bike geometry make all the difference between an
> > > easy, sweet-riding bike where you get the knack easily and within
> > > minutes, and a really tough dog? I seem to have made a tough dog.
> > > Anyone got any ideas about that, based on experience with several
> > > slightly differing geometries?
> > >
> > > Hwyl, Rh
> > >
> > > >Are you saying that you abandoned a beautifull trike design because
> > > >of rear wheel skiding when braking? I want to build a python trike
> > > >myself, so I wonder why you would worry about it. I mean, if just
> > > >the front wheel is enough for braking, then why bother about the
> > > >rear? My two wheel Python doesn't even have a rear brake. Or is it a
> > > >safety concern? Though, you could always fit multiple brakes on just
> > > >the front.
> > > >Please let me know you thoughts,
> > > >Patrick
> > > >
> > > ============================================================
> > >
> > > This is the Python Mailinglist
> > >
> > > //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.
> > >
> > > ============================================================
> > >
>
>
>
>
> ------------------------------
>
> End of python Digest V9 #118
> ****************************
>
>
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