engineering study of three wheelers
 

Jimmy Carter's Dep of Transportation paid for a testing and engineering study of three wheelers . A motorcycle magazine did a good story on it. The magazine had a road test of a American made three wheeler that was broth by Harrley Davidson and sold at the dealers. They loved it. It had a flat twin motor from a front wheel drive car and drove with the front wheels. It was long and minimized weight shift . And it was wider than a small car so it could really corner. Some one sued and they stopped selling it. The Federal tests showed the two at the front was the safest for most. Al the roll resistance is at the end with 2 wheels so a 2 at the front under steered in a hard corner. I still want to make one. In the 60's i saw a mine car whose front end was used to make a road racing trike. the "Moge" was short and was raced like motorcycal with a side car.The English bikeies liked the idea of it but hated to race. I have a small front driver that I still want to make into a "Moge." Builders may want to think about the Harley one for street use. Or the Moge for fun. And find the motorcycle magazine.

thats MINI CAR
 

thats MINI CAR

DAN -

Yeah, I would only consider a 3-wheeler with the two in the front. I love this one but it's built for speed and costs 2 arms and 3 legs :

T-Rex three-wheeler superbike
http://www.gizmag.com/go/3535/

CarloSW2

before and maybe after H. D. sold it their three wheeler was calledthe TRI-HAWK. I think.

Did you know that there is an EV T-Rex, called the Silence?

http://www.silenceinc.ca/accueilEN.htm

DAN -

Trie-hawk. That sounds familiar. ... Here it is :

TRIHAWK 304 - Road & Track -- Road Test - (from May 1982)
http://www.designmassif.com/trihawk/...ticle_text.htm

Trihawk Homepage
http://www.designmassif.com/trihawk/
http://www.designmassif.com/trihawk/...k_history.html
http://www.designmassif.com/trihawk/trihawk3.jpg

Ok, with probably only 100 built, that must be why I don't remember it. I like that it is very low to the ground (very stable, yes?). I'll bet I am mixing it up with a 3-wheeled Kit-Car with a similar(?) name.

CarloSW2

At the risk of pouring cold water on this it seems the main point is being overlooked here.
The donor car was the Citroen GS which was one of the most aero and fuel efficient cars built for the time.
It seated 5 , carried 16 cu ft of luggage and bettered 38 MPG from the factory. It also had disc brakes and self leveling fully independent suspension all round.

Personally I would be looking at that.

Cheers , Pete.

Peter7307 -

I don't know, it looks like the best (almost ;) ) real-world MPG car out there is a 3-wheeler :

Video: (definitely worth checking) test drive of Aptera @ Popular Mechanics
http://forum.ecomodder.com/showthrea...376.html?t=376

For me, this would be the ideal "super-commuter" for people (like me) that have terrible commutes.

The one thing I don't like is that the Tri-Hawk was only rated at 28 MPG in 1982. I thought that because of the 1.2 liter engine, it would at least have more get-up and go, but it *seems* to only have a ~10 second 0-60, based on the car magazine tests. Is a 10 second 0-60 really fast in 1982? It used a carburator and had no emissions equipment because it was classified as a motorcycle (right?). In 1982 it was around $14000+. The Aptera is about $30000, so I think they are in the same price bracket (i.e. pricey to say the least). In 1984 you could get a Honda CRX with better MPG for around $6000, so I think the Tri-Hawk would have needed a lot more tuning to make it competitive in terms of MPG.

CarloSW2

tasdrouille -

I know about it, but the $50K price tag is depressing. For that amount, it should at least offer a full enclosure from the elements. It's sooo beautiful and sooooo expensive, :( .

CarloSW2

I'll look through my log book for trike stability Sketches/models... It's quite simple to figure out that two in front has a higher stability potential compared to two in back....

Draw a triangle connecting contact patches.... Next - draw a vector from the Cg representative of force due to gravity (Fg). Then, draw another vector from the tip of the Fg vector parallel to the two front wheels (this would be 90 degrees from the front) that represents the force due to acceleration (m*v^2/r). Now - draw a ray that starts from the Cg and passes through the tip of the second vector.

If the ray passes INSIDE the triangle - the vehicle is stable (all wheels stay planted). If it passes through the line - it's critically stable (technically, an unstable condition). And if it passes OUTSIDE of the contact patch triangle - you'll lift a wheel.

Why does this make it obvious that a tadpole (2 in front) design is better? If the Cg doesn't move relative to the front - there's more "meat" of a triangle in the tadpole design compared to a delta trike (two in back).

I'd say that's debateable.

It depends on whether the trike in question is subject to greater accel or decel forces. Of course the normal street machine is subject to greater decel forces and so I agree the tadpole is more stable, more often. Something like the Vigillante, though, seems to do quite well with the delta style: http://www.vigillante.com/vigillante1.htm

Frank -

My friend just posted this one that is very stable because it does the "motorcycle-slant" thang :

http://www.carver-worldwide.com
http://www.carver-worldwide.com/UplF...s/_D7U0027.jpghttp://www.carver-worldwide.com/UplF...svoor-DBzw.jpg

But, they're pricey. It took me awhile, but it looks like they go for around $40K+ USED :

http://www.carver-worldwide.com/UplF...2008124741.pdf

CarloSW2

10 seconds to 60 was pretty quick in 1982.

For a modern version, check out the Lomax - there's both 4- and 3-wheeler versions out there. It starts from a Citroen 2CV chassis; for the 3 you remove one rear wheel and its swingarm, and turn the other swingarm over so it's facing inward. Funny but effective.

There was also the HMV Freeway, built in Burnsville MN. It was powered by a Tecumseh rider mower engine and could deliver 100mpg. Tandem two-seater. I'd like having one of those.

i was sure that the the three wheeler tested had a Citroen 2CV power unit. a 850 flat twin. they were sold in the us but fed. standards stopped Citroen here way back when. i hear that Canada is full of them, more or less. it was a very good sub vw bug car/truck. like a very, very plain suv. the bike testers said it was not fast on pickup. but it cornered as fast as any sports car. they loved it. its worth reading. back in the mid 60's( i think) think popular mechanics made a three wheeler with plans to short trip. it had some kind of a big lawn mower motor. it was short, high, and had the passengers way up front. i worud sit in a electric chair before i'd drive it far. three wheelers are light. but for going around corners and have places to put stuff, four is the way to go. right now i'd like to make a tube framed 850 or 1000 car with the motor in the back for street use. like a mini hot rod or sand buggy.