High torque velomobile

[jawnn]

The two front brakes of a trike must be synchronized from a single lever to prevent wobble and loss of control.

And hydrolic brakes are essential for syscronization, front or rear.

 

[jawnn]

Tadpole trikes need more weight on the rear wheel to prevent loss of traction if the rear breaks locks up while in an emergency stop and turn. The weight of the batteries and motor should help. Most light duty trikes don’t use a brake on the rear, but with 500lbs or more they really need all the help they can get to stop. Anti lock brakes would be the best.

Tadpole trikes hare less likly to flip over forward because of the crank boom, but they could use some help. And they definatly need the seat to be lower.

Delta trikes roll over very easy because their is nothing to keep the drivers weight centered in a turn. The only thing that can be done about it is to load the batterys at the rear wheels and lower the center of gravity. Then slow down.

I like the quads the best, (nice but no longer made)

 

[jmygann]

Quads are not bicycles like tadpoles.

Have you looked at the tripod ?

http://columbiacycleworks.com/index.php?option=com_content&view=frontpage&Itemid=1

 

[jmygann]

handling ? .... what do the Electrathons use ?? seems like a lot of tadpoles.

Jawnn,
Re-reading some of your musings on previous posts. You feel that it is incredible that you could build a trike that goes up steep hills at 20 mph. It is not incredible, it is very doable. With absolutely no pedaling, ever.

For the loads and hills you encounter, a 12 volt system at 20 mph using the 909 motor, alltrax controller and 60 amp hour thundersky batteries should be adequate. I say should be, I do not know what vehicle you are planning to build. To keep cost and complexity down, 12 volts allows us to use a single reduction drive. 12 volts allows the use of a single charger, and fewer cells to monitor and balance. This is itself a 2 to 3 hundred dollar savings.

Stability.
A tadpole is a very complex vehicle. A delta is a very simple vehicle.
You feel that a tadpole is more stable.
I say horse apples.
Take a piece of paper.
Draw a large circle.
Draw a capital T on the circle. The pillar of the t parallel with and on the line of the circle.
The T represents a delta or a tadpole trike.
There is a point in the center of the circle. Draw an arrow starting from the center of the circle right thru the center of your T.
That arrow represents the force. Centrifigal force. It is 90 degrees from your direction of travel.
Centrifigal force wants to tip your trike over, wether it is a delta or a tadpole.
To make a delta more stable, the seat is put near the rear wheels which act as outrunners, hopefully the rear wheels will resist the centrifigal force.
To make a tadpole more stable, the seat is put near the front wheels, the front wheels being the outrunners, hopefully the front wheels will resist the centrifigal force.

A tadpole, unless very carefully designed, is a much more unstable vehicle.
Hard braking, it tips forward because the center of gravity is so far forward.
uneven front brakes, cause it to readily go into a spin.

If you expect a tadpole to handle better than a delta, I hope to dash those expectations.
You may hear a lot of good things about tadpoles, but they are not talking about the vehicle you envision, and the forces on your vehicle.
20 mph and near 600 lbs. Your forces from turning and from braking are very large, 4, 5, 6, 7, 8 times the forces from a pedal powered tadpole with a 120 pound operator.
Unless you can engineer around the shortcomings of a pedal powered tadpole, you would be much safer with a delta.

From an engineering and design view, build a delta.

chuck

 

[jawnn]

Nice looking velomobile, but do you know anything about the stability? this trike has no rear brake and ties the motor into the pedal chain....I just don't think it work for my needs.

Quads are not bicycles like tadpoles.

Have you looked at the tripod ?

http://columbiacycleworks.com/index.php?option=com_content&view=frontpage&Itemid=1

 

[jawnn]

read more here: "Build your own electric motorcycle"

but I realy wish some one would write a book abou tthis subject. A 500lb velo mobile that can replace a small car around town. children and cargo realy add up fast, don't think that a small power system will work for such weight on the steep terain of the pacific north west....

http://commutercycling.blogspot.com/2010/10/secrets-of-motor-pedal-hybrid-design.html

 

[jawnn]

the stability problem has been fixed

http://www.lightfootcycles.com/

 

[amberwolf]

Except that quads are not bicycle-class vehicles in most places in teh USA, AFAIK, because they define bicycles as "two or three wheels in contact with the ground" or similar, in most state or local laws that have a definition.

Since there isn't a definition that encompasses a quad, it isn't technically legal to have on public roads, so if the local law enforcement wish to remove you from the road they can. For instance, here in Phoenix (and anywhere else in AZ I've seen them), the pedalable tourist quads are only in parks or private land, or simply displayed unridden in front of bike shops or tourist places, because they get harassed by the law, having no definition to defend their right to use the road.


If it werent' for that, I might well have built and be riding a quad, since it would greatly increase my stable cargo capacity.


My guess is that many places you would have no trouble if you were only pedalling it, but if you motorized it they would ticket you off the road pretty quick, like they would here.

 

[wojtek]

that is a beauty!

http://w-tomohisa.blog.ocn.ne.jp/photos/mountain_quad/_5200055.html

 

[Chalo]

Trikes are horrible twisty rickety junkheaps compared to bikes, and quads are worse. Quads must have articulating chassis or else have so much flex that they don't ever point any two wheels in quite the same direction.

You've really got to have some special need before trikes make sense. I get so much more utility, speed, and decent on-road behavior from a bike with a trailer than from any of my trikes that there is no reasonable comparison. From my experiences with Quadracycle, Rhoades Car, and Surrey, I'd expect a bike with a train of three trailers to be more efficient and more convenient overall than any of those. And you can carry more cargo on an Xtracycle or a bakfiets without a trailer than on any of the four-wheelers.

Chalo