Hey Matthieu,
Today a recumbent bike with (I think) the originally described geometry popped
up in my eBay search:
https://ebay.us/XTtuZR
You can google "Triker X3" to find more images. On the one hand, it's a child's
toy which hasn't been designed for your requirements (instead, to be cheap),
but on the other hand it means that the design is good enough for a product
than can be sold on the market, so that's something.
I suggest you try to find such a trike near you to do a test ride to hopefully
get some insights for your own design.
Good luck!
Matthias
On June 11, 2020 9:40:54 PM GMT+02:00, Vi Vuong <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
Hi Matthieu and All
I do have a skatebike in tadpole trike configuration. It’s fun one in
a while but quite uncomfortable. A recumbent seat would help but you
better have thick cushions. Regarding steering, low speed seems to be
Okay since the bike is quite wobbly. Rear steering should be Okay too
in low speed (delta trike configuration).
https://youtu.be/tts0DieTxeo
For practical use, I also recommend 20”, folding bike in a design that
you can ride. Then work toward compactness and portability. My most
practical folding bike happens to be a 20” python, which has not gone
through portability improvement yet...
http://en.openbike.org/wiki/Bipolar
Vi
On Jun 8, 2020, at 1:38 PM, mircosoft@xxxxxxxxxx wrote:"Bybal" which I tried to ride once as a kid. Basically a Halfbike
Thanks for the Halfbike video. It reminds me of something called
turned backwards:
https://www.bike-forum.cz/foto/detail/5356-br-rocketbearings and chain), but not that hard to balance. No offroad, of
I remember it was pretty hard to pedal (skateboard wheels, neglected
course - actually, even a small crack in the asphalt could eject you
easily. But it was definitely fun.
It looks very nice and interesting so I will definitely give it some
Mirek
______________________________________________________________
Od: "Matthieu Chastel" <dmarc-noreply@xxxxxxxxxxxxx>
Komu: python@xxxxxxxxxxxxx
Datum: 08.06.2020 18:40
Předmět: [python] Re: Advice on a (new?) recumbent trike design
Waow, thank you very much Mirek for the sketch and fast come back!
thoughts!! I would have to build the middle," 3-branches star", piece
in medal though because such design = enormous constrains on this
part... probably more than wood could take. And Steffen, your comments
are worth much more than 2cents (but I let people bet on the price ;p)!
beginning of my project and that I had stupidly lost: the halfbikeSince then, I found back a link that really comforted me at the
(see, for example https://www.youtube.com/watch?v=DMAjoa1cEek). The
principle is quite close even though the goal is very different :
halfbike for fun, mine for practical use.
different subject (wolves)... so, I am afraid I will have to put thisAlso, I just received some news from a fellowship on a totally
bike project aside for a little while. I will let you know for sure if
I go forward!
écrit :
Best
Matthieu
Le lundi 8 juin 2020 à 10:22:43 UTC+2, <mircosoft@xxxxxxxxxx> a
general idea should be visible. Hammock seat would be better for
Here's the promised sketch. The proportions are all wrong, but the
folding forward, or maybe there could be a slot along the middle that
would fit over the FW. Compared to the mountainboard design, the
resulting package would be quite bulky, but guaranteed to be rideable.
intended purpose. Rear wheel steering might work on a non-tilting
Good luck, whatever you decide to build!
Mirek
______________________________________________________________
Od: mircosoft@xxxxxxxxxx
Komu: python@xxxxxxxxxxxxx
Datum: 07.06.2020 09:54
Předmět: [python] Re: Advice on a (new?) recumbent trike design
Hello Matthieu,
To save you some dead ends: this design will not work for your
trike, but its track must be wide enough to resist tipping over - say
70 cm or more. And definitely no lean steering. With the mountainboard
rear axle, if you lean to one side, the rear end starts to move in the
opposite direction, increasing your lean - that's a positive feedback
loop which ends with you laying on the ground. Then there's the rolling
resistance of two small wheels - not the best to cover long distances
efficiently.
efficiency and cargo capacity, but there may be ways to combine them
Tiny size and foldability are usually the exact opposite of
all into one package. I think a 26" front wheel would be too big for
easy folding, 20" would be better (still OK for most gear hubs). Rear
wheels should be at least 16" to roll easily, but that's just my
opinion, I have never tried anything smaller than 20". They could be
mounted on two long cantilever arms, providing wide track for
stability, which could fold flat next to the front wheel. Steering
could be standard Python design with a pivot between the seat and the
front wheel (doesn't need handlebars), or the FW and seat could
lean/steer together while the rear axle stays horizontal (needs
handlebars on the rear part).
<balamber@xxxxxxxxx> wrote:
I'll try to make some sketches.
Regards
Mirek
On June 6, 2020 7:41:23 PM GMT+02:00, Tihamer Juhasz
experience isHi Matthieu,
I am not an expert in any recumbent related field, all my
(including onebuilding 8 different types/geometries of recumbent bikes
geometry orsitting/recumbent tandem). I haven't built a trike (python
canotherwise), I haven't built a rear-wheel-steering bike or trike. I
pleaseonly
give you my thoughts and ideas. They are just best guesses, so
unknownsdon't
get limited by them.
This is a very ambitious project as a first build. It has many
existingand
it will be challenging. For a first build, I would copy an
decentdesign,
because that would give me the best shot at getting something
inand
rideable.
You will definitely need to rebuild or at least modify it heavily
anthe
building process (especially since it's your first build and it is
budget.untested design), so plan for that in your estimated effort and
RWS
There aren't many rear-wheel-steering trikes and just one tested
andrecumbent bike in the world as far as I know. Search for RWS trike
butyou
can check them out. RWS has many challenges, I am no expert in it,
in aRWS
steering is no easy thing. You can find information on this topic
youquick search.
To turn on a skateboard I think that you pivot the board more than
yourpivot the body for the desired turning effect. While in a turn,
yourbody
is at an angle to counteract the centrifugal force in function of
myspeed, and the board is at another angle to achieve the turning
position of
the wheels. I think that these two angles are different on a
skateboard,
but they will be the same on a trike if you don't apply some fancy
mechanism to have a bigger board tilt than bike tilt. This is just
speed andguess, but please check it out. The body/bike tilt depends on
work,turning radius, so there is some thinking there to do to get this
tilting
mechanism right.
On the other hand, I was almost always told that my designs won't
toand
many of them worked because I did my research and put in the hours
themake
it work. Cutting up and welding together again is included in the
process,
so plan for that. Good luck and keep us posted on your progress!
Cheers,
Tiha
On Sat, Jun 6, 2020 at 3:09 PM Matthieu Chastel <
dmarc-noreply-outsider@xxxxxxxxxxxxx> wrote:
Dear openbikers,
First and for most, congratulation and thank you very much for
toofantastic website you created and all the great information yougathered
there. I also wish that the ongoing crisis does not affect you
mightmuch!
Following Steve Nurse advice, I am contacting you hopping you
havebe
interesting in, and may have relevant critical advices about arecumbent
trike I have been thinking about for few months and hope to buildbellow)
eventually. I have never seen the design I made (see enclosed or
and I am afraid that the steering I want to try won't besufficient...
hence the need for support before investing the little money I
volunteeringinto it
( I am just finishing my studies...). I am now doing a
build itwork in
a farm, hence, I might have the best and only opportunity to
transportationbefore a long while.
I spend quite some time thinking about "sustainable"
bellow).means.
This led me on the design draft you will find enclosed (and
manyThe
main idea is to have a comfortable and efficient bike able to do
forkilometres, ideally able to take a 60liter bag or more on it, butalso
"tiny"/"foldable" to take the train with it and carry it around
vehicle)...potential long trekking adventures (as well as every day
haveI
don't think that today's "folding bikes" really tackle thosecriteria...
and,
I dream to build the frame in wood, a material that I really like
above all, that I know more about than metal (and I think I will
madeeasier access to the tools it will require). The rest would be
wheelof
off-the-shelf pieces put together... So far, I plan to use aninternal gear
hub with paddle break (nexus 8 most probably, or 7??) in a 26"
onon the
front limiting lose wires around. At the back, I intend to use awith
mountainboard technology (
https://www.mbs.com/parts/12203-mbs-metal-matrix-ii-truck-system)
wheels as small/flat as possible and wheels that can be mounted
with(this
bring me to 6,5 inch or 8" mountainboard wheels/tire or I need tobuild my
own wheels and find some 12mm axis hub...). Perhaps a longboard
efficient?tire
wheels (like Nordic Roller wheels) would be lighter/more
onlyInitially, I dreamt that this mountainboard truck would be my
doubtsteering/tilting/suspension system, all in one! But I start to
<https://electric-skateboard.builders/t/3-wheel-frankenboard-c8080-70kv-12s-vesc-mbs-matrix-custom-9-layer-vacuum-press/1366/6>(here
are links toward the closest project I can findFrankenboard|
https://www.youtube.com/watch?v=J9dzPExq91k
https://www.youtube.com/watch?v=j6nIX1dQ-bk and to 3 wheel
C8080 70kv| 12s| VESC| MBS Matrix| Custom 9 layer vacuum press
ofand will try to contact the person). It is the most critical part
use,this
project and part for which I would be very grateful for your (orfriends of
yours in the domain) advices.
I like the idea because I would have very little metal pieces to
quiteno
need for any steering handle and I would have a kind of tilting
effect/advantages... But mountainboard wheels risk to create
amsome
drag (I found some "road wheels but they remain very large) and I
truck/bikeafraid
it won't give me enough turning radius... To avoid this turningissue:
- I can use very soft strings and make the angle of the
onfixation steep but it is a risk of riding like a fish when I am
goodstraight
roads... It might be possible to create a system to adjust thestrengths of
the strings at any time while ridding though... That might be arelevant
solution?!
- I can reduce the front-back wheel distance but only within a
Istability length limit!
Mixing those 2 worlds - mountainboard/bike - is risky I guess and
ordon't
have any old or scrap material with which I could try a prototype
unfortunately. Imake
proper measurements before buying the final material
wouldalso
dreamt to use second hand material as much as I could but I won'thave
time for this unfortunately and the virus crisis does not helpneither...
from the
Finally, I intend to split the "front wheel + transmission part"
"main axis + back wheel + seat part" in two pieces. The joint
thenbe
bellow the bottom of the rider more or less. Those 2 parts could
usedbe
carried separately for transportation. When disassembled, I wouldthus
have 1 wheel in one hand and, on the other one, or attachedvertically on
the side of a back pack, the "main axis", with 2 "bars" normally
course,to
make the seat just around the rider's spine now folded along thismain axis
and the mountainboard truck at the end of this same axis. Of
thusthis
separation will bring fragility and/or weight! I could use this
"separation" point to create a steering on the front wheel and
aimprove
steering... but I don't think pedal breaks on a steering wheel is
amsafe
idea...probably
I hope that, thanks to the draft scheme bellow, this long and
messy description in my broken English will make sense to you. I
(planshappy
to give more details or reformulate later!
If, one day, this project becomes reality, I shall share it
riders ifand
pictures) opensource of course!time and
I would be very grateful to receive your comments if you have the
the energy. Do not hesitate to forward it to other relevant
============================================================you============================================================
think it can help (also mountainboard riders perhaps?).
I remain at your disposal for any questions you may have.
Looking forward to hearing from you,
Kindest regard,
Matthieu (from France)
(whats'app 0033 782 178 800
PS: I am happy to subscribe to the mailing list!
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