Are Tadpoles stable at 30mph? I purchased Atomic Zombie plans for...

Roadkill

Roadkill

New Member
I purchased Atomic Zombie plans for 6 designs. One was a Tadpole with tandem seating and a flatbed. There is also a StreetFox 4 wheel bike as well I am considering.

I am concerned about stability at high speeds not hugging corners at low speeds.

If you know of any threads that address this or just success stories in general.. Please let the info fly here!

My friend said that he rode a SUN and slapped a motor on it and it stated not to go over 15 on the frame. He said it was very scary. Those wheels were at a 45 degree or similar angle.
 
Roadkill said:
I purchased Atomic Zombie plans for 6 designs. One was a Tadpole with tandem seating and a flatbed. There is also a StreetFox 4 wheel bike as well I am considering.

I am concerned about stability at high speeds not hugging corners at low speeds.

If you know of any threads that address this or just success stories in general.. Please let the info fly here!

My friend said that he rode a SUN and slapped a motor on it and it stated not to go over 15 on the frame. He said it was very scary. Those wheels were at a 45 degree or similar angle.
Click to expand...

I have recumbent experience both as a rider and designer/builder, so I might be able to add some insight. First, I think you should ask your question both at bentrideronline and the Atomic Zombie forum for both unbiased and perhaps biased views.

As for the AZ designs, I have read (and have witnessed in pictures and words) about designs that have evolved over the years from quirky designs to somewhat mainstream designs. There appear to be a lot of builders. One thing that has not changed is the build technique and associated weight. They're made from relatively crude materials and are thus heavy. Might be OK if you are going to stick a big motor on it.

As for the Sun trike, which one? They used to make the USX which was a delta (two rear wheels, one front) which was kinda low slung and cool looking (think it was only offered in a copperish color) and still offer the EZ3, which is offered in silver, blue, red and perhaps other colors. That one is taller and more unstable due to its CG. They also used to offer a tadpole design (two front, one rear wheel) but I think that was discontinued. Appeared to have a higher CG than most tadpoles, I think to allow the main beam to be fairly straight.
 
It was tadpole one and he said wheels angled left and right some as to hug road better and not flip or something. I think the centrifugal force might have made them unstable at high speeds because of the slight tilt. I will hit other forums and see there. I may first read more here and gain as much knowledge first before a build of my own.

Thanks for the thoughts.
 
Roadkill said:
It was tadpole one and he said wheels angled left and right some as to hug road better and not flip or something. I think the centrifugal force might have made them unstable at high speeds because of the slight tilt. I will hit other forums and see there. I may first read more here and gain as much knowledge first before a build of my own.

Thanks for the thoughts.
Click to expand...

A couple years ago there was a guy in Arizona (I think, or maybe NM?) that designed a motorized vehicle around a Sun delta trike, believe it was the USX. Had front and rear fairings. The rear fairing encapsulated the rear mounted engine. Pretty cool, called it the Goblin. Simple drivetrain off the rear transaxle.

goblin.jpg


http://greatgreengadgets.com/gadgets/2009/01/27/goblinaero-velomobile-150-mpg-available-in-feb-2009/
 
Any three wheeled or legged device is less stable that two or four wheels (legs). It's pure physics. Nevertheless, two wheels leading and one trailing will be better than the opposite. A two wheeled bike is more stable due to gyroscopic effect that tries to keep the wheels upright and going straight. Properly balanced a two wheeler is more stable.
Weight transfer also comes into play. When you load a single front wheel the weight can run outboard of the centerline which can cause tipping (see Dan's link).

Tom
 
2 door

Danny 2 stroke if a very funny man, my belly is sore from laughing!! A

m wondering if he looks as funny??!! lol.

After watching that video, can you picture Dan in his flying motorized bicycle!!

Ron
 
I thought as much.. I rode my GEBE fix attempt to Lake Michigan today in the Sandy wind gusts, was turned away by officer nice and then the belt started to fray from not being perfectly centered. Still I will cook the threads off and tweak new ideas pondered. Lots of hacking and welding here. I will try the tadpole in spring perhaps. Thanks for the insight all!

2door said:
Nevertheless, two wheels leading and one trailing will be better than the opposite.

Tom
Click to expand...
 
You must log in or register to reply here.
Back
Top