Well, actually what I was trying to describe was this: take an ilean system,
then turn one of the cranks 180 degrees (so both of them point rearwards) and
put stops with rubber blocks above both cranks. The rubber provides suspension,
the axle prevents leaning (rather than facilitating it as ilean would).
Fixing the axle in the middle or having two staggered axles as torsion bars
means independent suspension with no anti-lean properties (so the trike would
lean out of corners). Basically the same effect as two independent swingarms
suspended on each own's rubber block or shock unit, just with the springy
elements in a more convenient place. Should work, most trikes do it this way.
Ilean with a long axle means leaning into corners (with built-in maximum tilt
lock), plus torsion bar suspension, plus the inherent "halved bump suspension".
Needs balancing like a two-wheeler (unless you link the tilting to a control
stick which you could operate manually and force the trike to any angle you
want). Should work too.
Torsion angle formulas:
angle=(torque*axle_length)/(G*Jp)
where G is the material's shear elasticity module and Jp is polar quadratic
moment of the axle cross-section. For a hollow tube, it is:
Jp=((pi*D^4)/32)*(1-(d/D)^4)
where d is the inner diametre and D is outer.
G might be something around 8*10^4 MPa, but I'm not sure what material it is
for (steel?).
M.
On February 17, 2020 12:02:27 AM GMT+01:00, paul needham
<paul.2.needham@xxxxxxxxx> wrote:
Mirek============================================================
So the axle will become a torsion arm spring giving anti-roll as a side
effect.
Somewhere on the net there is a torsion spring calculator that would
tell the arm thickness for a given load and length ?
Wonder what would be better :-
One axle welded to each swing arm ?
Two axles half the length of the above ?
Two axles same length as single side by side , slightly staggering
wheels ?
This arrangement would be very compact and fit in the unusable area
above the frame and directly behind the seat :-) that I like.
regards Paul
On 16/02/2020 18:00, mircosoft@xxxxxxxxxx wrote:
The swingarms would be welded to the axle. So if you lift one wheel,the other one lifts too. Torsional stiffness of the axle determines the
amount of lift: perfectly stiff = no cornering roll, but some "bump
roll" as with unsuspended trike. Perfectly flexible = the same as
having two independent swingarms. Some sweet spot in between = optimum.
you would only need two bushings at the axle ends, not two bushings for
Thinking more about it, it would also simplify the bearings, because
each arm. And the axle would make a nice long torque arm to catch
lateral loads from the wheels.
designed my trike without suspension :-D.
Hmmm... I guess I should have come up with this idea before I
<paul.2.needham@xxxxxxxxx> wrote:
M.
On February 16, 2020 12:27:05 AM GMT+01:00, paul needham
andMirek
Not sure why this produces anti-roll ? if the swing arms can move
around
the axle then it plays no part in anti-roll ?
Surely anti-roll should be a rod between the swing arm wheel ends
Rubberthe chassis ?
regards Paul
On 15/02/2020 16:42, mircosoft@xxxxxxxxxx wrote:
Hi Paul,think the best option would be to mount the wheels on swingarms. The
Considering your cantilevered rear hubs and heavy duty loadbed, I
axle they swing around can go all the way through and link them
together, reducing outward leaning in corners ("anti-roll bar").
layersblocks would fit this setup pretty well.
Regards<dmarc-noreply@xxxxxxxxxxxxx> wrote:
Mirek
On February 15, 2020 4:49:24 PM GMT+01:00, Vi Vuong
Hi Paul,
Have you tried thicker seat cushion? 2” dense foam over few
leanof
<paul.2.needham@xxxxxxxxx>cardboard is good enough for me. Soft balloon tires also help.
Vi
On Feb 15, 2020, at 3:14 AM, Paul Needham
outwrote:
Gerald
I ride over poor surfaces but no the kind that would be smoothed
consideredmuch by having the whole rear end sprung.
I was hoping that by using the ' bike ' suspension for each rearwheel it would reduce the individual load on the pivot components
compare with both wheels pivoted and sprung from one point ?
As I cannot ride a Python bike and only a trike I have not
leaning , or course leaning on it's own is not suspension it just
reduces the cornering forces and increases complexity and weight.
regards Paulwould create outside lean when cornering? Unless you hace some
On Sat, Feb 15, 2020 at 8:57 AM Gerald <bepb@xxxxxx> wrote:
Hello Paul,
any special reason for separate suspension? I would expect that
asteer construction in mind?
I am thinking about suspention for my trike too. It can give you
rubber<paul.2.needham@xxxxxxxxx>:nasty shake, specaly in Winter when one wheel might have to run on
gravel or ice.
regards Gerald
Am 15.02.2020 07:56 schrieb paul needham
corneringJürgen
Each wheel with a block of it's own.
I realise there is a risk of it not being rigid enough for the
stress ?
Only one way to find out :-)
regards Paul
On 15/02/2020 06:53, Jürgen Mages wrote:
Hi Paul,
do you want to suspend the whole trike rear end with one
<https://atomiczombie.com/forum/threads/my-life-with-python-trikes-mk1-mk1-5-mk2.33/>block,
oder each rear wheel with its own block?
regards Jürgen.
Am 14.02.2020 um 09:05 schrieb paul needham:
Hi all
Been riding my trike for 6 years now My Python trike builds
dimensionshowever a fewand fancy building a new rear end with suspension.
The original Python suspension looks the easiest option ,
questions ?
1) Will using 20" forks and wheels change any of the
============================================================? I am============================================================
from innerunder 80kg but may want to carry up to 20kg of camping gear ?
2) Is the rubber block available in Germany say from Ebay ?
3) If I decided to make my own as suggested using circles cut
mind theretubes how tall should it be ? and what diameter bearing in
python-request@xxxxxxxxxxxxxwill be 2 wheels suspended.============================================================
regards Paul
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