engineering study of three wheelers

[DAN]

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.

[DAN]

thats MINI CAR

[cfg83]

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

[DAN]

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

[tasdrouille]

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

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

[cfg83]

DAN -

Originally Posted by DAN

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

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

If you still need some clues about what EXACTLY a Trihawk is, I'll try to quickly fill you in. It was initially built in Mokena, IL before moving west to California. Production was limited to 1983 thru 1985, with less than 100 vehicles produced.

...

The front-wheel-drive engine/tranny combination was borrowed from the Citroën GSA, a car which was never imported into the US. The 1299cc 4 cylinder boxer engine was well suited to the task. Other components were borrowed production vehicles, such as the front suspension and rear trailing arm coming from the Renault R5, steering rack from a Renault Alliance and dash gauges from Honda.

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

[Peter7307]

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.

[cfg83]

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

[cfg83]

tasdrouille -

Originally Posted by tasdrouille

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

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

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

[trebuchet03]

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).