Neat tilting delta Python trike

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The more I think here the more that having a separate tilt system acts to assist with the steering, making the hands free steering part easier to control than a non-tilter with hands free steering.
That is how the flevo bike works. It combines both for steering. But it has that disadvantage of steering when you are on a camber.
Dannyc his tilting system, doesn't has that problem and the steering is completely separate from the tilting.
 
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So have have a plan a 3 parter in actual fact.

1) add a set of bars to current ridable Python on the non moving rear - can I ride it ? am I happy riding it ?

if so onto :-

2) turn mule into a simple Flevo/Python hybrid copy ?


The mule consists of a long spine and front end joining plate with a bolt on rear axle.
If I reverse the spine putting the unneeded joining plate behind the axle I have a straight box section with nothing at the front.
Add a traditional Flevo elastomer and 12mm rod end for the pivot.
Then all I need is a seat mount with a front end joining plate and it bolted to the elastomer and rod end bearing.

and if that works [ it may be a bl**dy miracle ! ] :-

3) try higher seat and narrower track .......

Paul
Ok my post #41 shows we do not need Part 1 of this plan , as Flevotrikes are found with handle bars that are on the front steering part.

So on to Part 2 !

Male Female Bobbin
- Model: 5045MF28-60
- Diameter (D): 50
- Height (H): 45
- V: M10
- I(mm): 28
- Max Load (Kg): 84.0
- Deflection (mm): 4.0
The following have been ordered only think I could not confirm was Sure number hopefully around 55

Paul
 
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Ok my post #41 shows we do not need Part 1 of this plan , as Flevotrikes are found with handle bars that are on the front steering part.

So on to Part 2 !

Male Female Bobbin
- Model: 5045MF28-60
- Diameter (D): 50
- Height (H): 45
- V: M10
- I(mm): 28
- Max Load (Kg): 84.0
- Deflection (mm): 4.0
The following have been ordered only think I could not confirm was Sure number hopefully around 55

Paul
Well front or rear it seems. They have 2 spots to mount the handle bar. Why I don't know, but probably a personal choice that decides what location you use.
 
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If using a Mosquito rear you want to cross the links not use them as the Mosquito does.



In the top pair we have the std Mosquito links which move the top bar and therefore the seat towards the outside in a corner. Crossing the links gives some movement to the inside. Also note that this particular set-up slightly raises the rider as it leans. The centre of the top bar goes up with the crossed beans but down with the std Mosquito set-up. Given any system likes to find it's lowest energy it will naturally want to find the lowest seat position and so the crossed links will naturally hold the rider stable and upright. It will take a small effort on the bars to initiate lean and a releasing of bar tension to come back upright. With the std Mosquito bars it's exactly the opposite in that it naturally wants to fall over and requires effort to pull back upright. The crossed links are a better system IMO and you can play about with different bar lengths and pivot points to suit.
Like this you mean ?


Corners nice and tight !

Paul
 
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Yes like that.
Very short wheelbase but nice design.
I would make it a bit longer, so you don't hit the rear wheels with your arms, but other then that, it looks great.
It also looks if he has some suspension, or is it just his seat that lowers as he sits in it?
 
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I like that one more than this one.
I prefer the mosquito system above a single point, but I think it is something for you.
It has more luggage space.

 
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That short one is excellent. The thing is built exceptionally light from what I can see and uses rods not cables for the tilt. By moving the rear axle back you could create plenty of room for cargo behind the 4 bar link. The second one displays what I was saying about fixed bars. On turning they have a fully extended outer arm to hang onto the bar whilst the inner one is in their hip and that's on a fairly low seat height. Raise that seat any higher and you'd need a gibbon to pilot it.

Another vid of the 4 link trike here showing it's hands off stability.
 
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The weight is about 14kg. He added the triangle as the bottom, what makes that it doesn't only depends on the angle of the rear cris section like other mosquito trikes.
That one has 20 inch rear and 26 front, but he has also 2 other versions with other wheel sizes.
For what I could understand, the trike is self leveling and stable.

Yep only thing you need to do, to get more luggage space, is moving the rear wheels further back.
You increase the turning circle, but with some changes, you can make it small again.
 
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I made a mistake and got more info. His final version of the tike is 16 to 17kg.
He has problems with a few things like stability on high speeds and with bumbs. He could solve that, but then the turning circle became bigger.
He changed the wheelbase to make it shorter.

HHere is an image of his last build. It has now 20inch wheels.


Here is the link to the forum.

http://velorizontal.1fr1.net/t25082-eivax-trike-td-delta-pendulaire-auto-stable

It is all in French, but Google translate helps a bit.
 
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Hi all
More Python hybrids , had pictures all along !



The one above is a bicycle conversion hence the empty hole where the rear fork suspension pivot was , it would have had an elastomer in the same place however the fork would have been inside the upper tube.



and for the more weight challanged ?



Elastomers ordered just need a female M12 rod end bearing and we are good to go.

Paul
 
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Unless DannyC builds it ? then on a cambered road it folds in the middle with the pivot heading for the gutter and the trike and rider making a dash for the other side of the road ...:whistle:
Yes indeed! The "dive across into oncoming traffic" behaviour was really off-putting.
To fix it we shortened the rear half of the trike's main keel behind the pivot. It seemed as if the pivot was so friction-free that the riders weight was enough to allow the trike to bend in the middle down the slope of the road camber.
 
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Elastomers ordered just need a female M12 rod end bearing and we are good to go.
Good to see you back in harness making Python MK?.? :p
 
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Put bar "receiver" on both sides of the pivot and get to try it out in either flavour?
My bar(s), are in 2 independent halves and can unplug from the sockets, so it would be easy to do.
 
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Emiel

sorry should have posted that with the video , I think his stability/turning circle problems are a common thread amongst some of these geometry based builds

Paul
They normally solve that by increasing the turning circle. That makes it stable.
They also only tilt in a corner, where other systems like the design that DannyC uses, tilt also on a road with a camber.
You could ad dampening to the rear wheels, to make it more stable on a bad road, but that makes that your trike will be heavier.

It depends on several thing, what design is best for you. Road conditions, the speed you ride, what you want to do with it. So does it need to cary luggage or not and how much.
With that, you need to look ad the options and see what negative point is the least negative for you and brings the most positive things for your usage of the trike.

I like the mosquito design. I find that French design complicated and wouldn't go for the triangle on the bottom. I understand why he did that, but it isn't needed.
 
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I wish there was a good view of the steering rods at the rear on that cross linked trike. I think I see what he's done to steer it which obviously works but would really like to confirm that via a decent picture. It also looks like he did a lot of his designing in steel rather than CAD. There's a lot of reworking of the metal.
 
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Yeh, that's what it looked like. Somewhat indirect in that the obvious place to act on would be the 4 bar link. It appears to work vey well though and is much better than a cable operated system.
 
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