(Trike for) Velomobile.... from scratch.

mjg

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Hello evrybody.
I have been looking at VMs for a few years and I have quite a bit of building experience so I think I would like to try to build myself one.

I have a general sense of the process.
The first question for today is which trike for a velomobile?

Thoughts on the Warrior?

MJG
 
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If you have been looking for a few years you will see that :-

99% of VM's have at front suspension - Rotovelo has none
98% of VM's have rear suspension - Rotovelo and some WAW's have none

You will need suspension if you intend riding it fast , it's a safety think.

If you only want weather protection , non suspended could work depending on where and on what you plan to ride ?
 

mjg

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By looking, I mean longing for....
My initial thought is to build a Warrior adding sull suspension. But I am not sure this is a viable set up.

What would be the trike to build to then turn it into a VM?
 
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Front suspension on a "self-build" tadpole trike is a bit fraught with issues.
Suspension messes with the steering geometry on heavy cornering and hard braking and this is why it is typically only the main manufacturers that offer it as they have the research,machine tooling and jigging to make it work safely. For a hobbyist it IS possible, but also comes with a host of compromises.
Rear suspension for a tadpole is easy as it is just stolen from the bike you cut up for its rear-triangle frame (as per Street Fox).

I have shied away from suspension (front or rear) and opted for balloon tyres instead (big-apple+) as they offer a softer ride with very little downside.

Good luck in your plotting, planning & scheming towards your Velo.
 

mjg

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Front suspension on a "self-build" tadpole trike is a bit fraught with issues.
Suspension messes with the steering geometry on heavy cornering and hard braking and this is why it is typically only the main manufacturers that offer it as they have the research,machine tooling and jigging to make it work safely. For a hobbyist it IS possible, but also comes with a host of compromises.
Rear suspension for a tadpole is easy as it is just stolen from the bike you cut up for its rear-triangle frame (as per Street Fox).

I have shied away from suspension (front or rear) and opted for balloon tyres instead (big-apple+) as they offer a softer ride with very little downside.

Good luck in your plotting, planning & scheming towards your Velo.
Hey Danny, thank you for that. Wondering if one could not simply plug also from a hack set of bike wheels the front ones. Is this a silly question?

Are you riding a velomobile or just the trike with the big apples?
 
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Hey Danny, thank you for that. Wondering if one could not simply plug also from a hack set of bike wheels the front ones. Is this a silly question?

Are you riding a velomobile or just the trike with the big apples?
Hi there, I have 2 active trikes at the moment (a Tadpole on Marathon+ tyres) which is a fairly harsh ride only moderated by the trampoline seat which provides some cushioning from the shocks (Loki trike) see below.



The other trike is a Python trike (Vespa) and that is on Big-Apples and the difference is really noticeable. I had issues with this trike climbing over the camber of the roads so it had to be shortened a lot to make it not do that. The suspension seen here is totally ineffective and could be a solid link. The idea was to make a trike that the wheels "popped-off" (they are on titty-pins) and the rear half could be swung under the front half for putting in a car (just remove the M8 QR bolt).


Working on a third trike (delta) but am nowhere near anything presentable/ride-able yet.
 
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mjg

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Hi there, I have 2 active trikes at the moment (a Tadpole on Marathon+ tyres) which is a fairly harsh ride only moderated by the trampoline seat which provides some cushioning from the shocks (Loki trike) see below.



The other trike is a Python trike (Vespa) and that is on Big-Apples and the difference is really noticeable. I had issues with this trike climbing over the camber of the roads so it had to be shortened a lot to make it not do that. The suspension seen here is totally ineffective and could be a solid link. The idea was to make a trike that the wheels "popped-off" (they are on titty-pins) and the rear half could be swung under the front half for putting in a car (just remove the M8 QR bolt).


Working on a third trike (delta) but am nowhere near anything presentable/ride-able yet.
I wonder if my tadpole trike approach to VM is not the wrong one. SInce I have seen people build planes in their garage I find it hard to believe that a VM is beyond the viable. But I have no understanding of what could go wrong. I am thinking that the central mast suspension from mountain bikes plugged into each of the front wheels could be enough but I am probably wrong.
 
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I wonder if my tadpole trike approach to VM is not the wrong one. SInce I have seen people build planes in their garage I find it hard to believe that a VM is beyond the viable. But I have no understanding of what could go wrong. I am thinking that the central mast suspension from mountain bikes plugged into each of the front wheels could be enough but I am probably wrong.
If you mean a standard suspended MTB fork for each of the front wheels? Yes, people have done that, you can give it a try.
 
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For a velomobile I would go for a kmx style trike.
You can af rear suspension but the main reason is, is that you can easily use the frame to mount the body to.
Best is, to design a frame that is low and had a main horizontal low part under the seat.
 
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I wonder if my tadpole trike approach to VM is not the wrong one. SInce I have seen people build planes in their garage I find it hard to believe that a VM is beyond the viable. But I have no understanding of what could go wrong. I am thinking that the central mast suspension from mountain bikes plugged into each of the front wheels could be enough but I am probably wrong.
Hi there

Well tadpole trikes need 3 things for them to act safely when ridden ?

Castor
Ackerman
center point steering

These would be very difficult to achieve using the suspension forks from bikes.

But hey I have NEVER built a tadpole and have little intention of , so am only talking theoretically ;)

Someone built a plywood prototype with forks cut down as front struts [ think 1/2 a fork per side ] IIRC the ride was described as plush however it wallowed around corners.

You would probably need kid's bike forks as a lot of adult one's have suspension in one leg and damping in the other ?
 
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Using front suspension forks on a tadpole means there's a lot of height to the chassis above the front wheels. That'd be difficult to build a body around and still see forwards. I've seen plenty of non-suspended trikes with bodies on them. If you really want a tadpole with some front suspension then either flexing wishbones or kingpin coils would be the way I'd go.





The former is the better option as I see it but needs some thought to get the right rate and the required composite material isn't cheap. The latter is very cheap but unless the sliding part is perfect there'll be some axle wobble. The latter gives very little suspension travel as well but you can't have a long travel front suspension anyway as then it'll then roll like a ship in distress in a corner.
 

mjg

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OK, so here is the question from the very top restated.
Is this worth the try? It seems that the technical challenge is not something that can be hamdled in a home workshop. THoguhts?
 
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I have seen that they build them as home in their garage. So it is possible and it's ip to you, how hard you make it. You can go easy with the design so it is easier to build, or make it complex and the choice of materials.
 

mjg

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Would a delta do better than a tadpole in terms of steering and safety? Also in terms of simplifying the process?
 
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A delta with steering would have a smaller turning circle.
Safety I don't understand what you mean. Both can roll over as you mean that.
I don't want to say that one is easier than the other.
I wouldn't go gor a surten frame and just put a body on. I would look ad the outer body and see how the make a frame, that works with that body. So that the trike frame holds the body and can strengthen surten points.
 
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The sprung wishbones is a doddle to execute once you've done the maths to get the right amount of it. The coil on the kingpin is not hard either - it's a simple bushing with an extra long bolt, spring and endplate.. I'd regard both as perfectly DIY. If you want suspension at both ends a delta is probably easier but does raise the front chassis right in your line of sight. Any bodywork will need to allow space for the pedalling action and may require a more upright seat than you would otherwise use to enable you to see over it because of that.

As a general rule:-
Delta - tighter turning potential
Tadople - better high speed cornering stability
You can make a tadpole turn tighter than SOME deltas and you can make a delta more stable than SOME deltas but you're at the extreme end of the spectrum for both of those scenarios.

As to simplicity, it's very hard to make a body that looks good, is lightweight and rigid let alone simple. You may get three of the four but all 4 is a tough ask. It usually requires plenty of craftsmanship to get the first three points. Those that do get made are very often the product of a home workshop. What base you start with will largely depend on what shape you want to achieve, whether aerodynamics is the most important factor or weather protection is and what skills you have with such things as plywood and fibreglass. If your skills there are insufficient then you'll probably be looking at making a frame and covering it with Correx or canvas or Cordura etc.

One thing you could consider is making a monocoque frame out of plywood and using that frame as at least part of the bodywork in a similar manner to these:-



The one above is rear steer and has front suspension. It's also FWD and much narrower than a typical tadpole as no room for turning front wheels is needed. It's much easier to add front suspension to a tadpole if it doesn't steer via the front. The frame is a simple affair but easy to add a canopy and front to by simply bringing the steering levers inside.



The one above has a LOT more craftsmanship put into the plywood. Note even the rear swing arm is a wooden box section. The builder has used the minimum of wood in as strong a way as possible similar to how an early biplane would have been made.
 
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The craftsmanship is great, but the function would be much better with a delta configuration. Rear wheel steer is OK for low speed use but tough to design for high speed use. Roll over prevention would be much better with the seat between the 2 wheels. Stability width becomes smaller as the CG gets closer to the single wheel end.
I don't know what the use of this, but I first saw it as a delta velo. Then realized it was a tadpole.
 
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As you want a good body around your trike, Tham it's best to design a body and a frame.
Or do what Popshot showed. A wooden base.

You can use something like carbon fiber, but then you really need to design the frame and the body togheter for the best result.

Some made a body with coraplast body. It's light and easy to shape. It seems to work good, but the body is there only for a lower wind resistance.
 
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OK, so here is the question from the very top restated.
Is this worth the try? It seems that the technical challenge is not something that can be hamdled in a home workshop. THoguhts?
Sorry I did not mean to derail your idea and create problems for you.

yes it is worth a try , you may hit the right combination first go ?

the suspension is to try and keep as many wheels as possible ' on the tarmac ' for as much of the ride as possible.

as you go faster you tend to get launched into the air , when this happens to the front wheel of a Python delta trike that both steers and brakes on the front wheel you have a near death experience [ yes been there and put a brown stain on the bottom of the tee shirt ! ]

the main problem with a tadpole is getting suspension without bump steer , hard to achieve no matter what you choose as the springing medium.

this shows the design of a trike/shell with reasoning behind decisions and trade offs etc :- John Tetz foam vm

real velomobiles suspension

a quick run down of most designs suspension styles
 
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Definitely worth a try because even if you only have a "partial-success" you will still have a working trike and even if any velo-body on top is less than perfect in all respects it would still be more than most people have.
Give it a shot, you may surprise both yourself and the rest of us mere bystanders. ;)
Personally, I would try the Street-fox style with rear suspension, but use Drum-brake hubs up front and do the "proper" job on the steering layout using Peter Eland's design spreadsheet.
 
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