Anyone see this 3 wheeled Metro?
 

There is really no information on the site about the car. Seems like it's a finished project also. From the Geo Metro Forum...............

Needs to get into some major body work, IMHO. Taper it down from the doors back. As it is, it looks like it'd roll, or at least drag the rear edges, under anything like hard cornering.

I bet it doesn't drag! I wanted to do that to my car years ago and mathed it all out. It would have had stability roughly comparable to a Dodge Maxivan- so nothing too dramatic about it. I wonder if/how much the fe went up as a result.

P.S. It might be possible to lift a wheel under hard cornering if he were to do something like stuff the back seat with heavies, leave the front pass. seat empty, and drive like a maniac. It might be fun to explore the limits.

P.S. again: Oh, I see there is no back seat. I doubt he'd be able to lift a wheel unless he got pretty extreme with it.

Thanks for the link Johnny... did I ever tell you you're my hero?

That's wild! Nice find, Mullet!

I'm with James: now that that's done, taper, taper, taper.

As for stability, click through to his "site" and have a look at the thick anti-roll bar he added to the front.

Shutterfly

Anyone notice the motorcycle muffler? It's a slip-on.

I'm wondering why he didn't just use a rear swing arm from a bike and mount a car tire on the bike rim. Proabably would have been easier, since all the work is already there, you just have to mount it and mount the shocks if it's not a solid swing arm.

Still, funny, if nothing else. I bet the cops don't like it.

Bike swingarm = not built for lateral forces.

Check out the Yamaha 3-wheeled bike.. it's basically a bike frame in the rear with a tube chassis connected to it.

Also, most sport 4-wheelers have the same type of swing-arm that sport bikes have. There is only one pivot bolt. holding it to the frame.

And how much do they weigh?

Bottom line is this application sees FAR more lateral forces than bike swingarms do. And more weight besides. I wouldn't trust a bike swingarm on the back of my car, but that's just me.

I dunno, those Yamaha things are pretty hefty, and the moment of leverage is much further back than on a Geo... since the 1000cc to 1300cc engine in sitting in the swing-arms connection area.

Not disagreeing with your concern, but it just seems like it should be OK. as long as you're not using it on the front of a lincoln. :D

I have spent an inordinate amount of time obsessing over such a project. Other considerations besides the overall strength and ability of the swingarm to resist lateral (and torsional loads, depending on design) are being able to use the same or similar automotive wheel and tire as the front has, and being able to use an automotive brake (including parking brake), being able to fit a stout enough spring and shock, and being able to change the rear tire without having to jack the rear end up three feet in the air or put some sort of access panel in.

Also... what Yamaha things are you referring to? A quick Google shows mostly single front wheel trikes...

Cool part of a bike's rim and swing-arm.. you just take the axle bolt out, and drop the rim/tire.

Bike rims will accept car tires.

the only thing that really needs to be adressed is whether the bike's swing arm will handle the torsional/lateral loads of a small <1 ton car, even with the worst drivers in terms of cornering.

I'm sure you could use a cheap LP tire, since I can get Wanli 18" tires for less than most standard passenger sizes.. and they still last for up to 30,000 miles.

Tire prices for 16/17/18" semi-performance (street) tires

Are bike RIMS comparable to auto rims re: lateral strength? I'm thinking, probably not.

Plus, that's bike stuff I'd have to go out and buy. The car already has a nice wheel/tire/brake/parking brake/bearing/spindle/hub/strut/spring assy already nicely made up.

I planned on converting a Tempo- 2500 lbs empty weight, and I wanted to keep the back seat so had to figure that weight and balance at capacity as well. It is conceivable to have 500-600 lbs. in the back of the car, and even more if there's any trunk space left to use.

The aluminum alloy (mag) bike wheels are manufactured using the same processes as car rims are, so I'd assume they're straight.

Your second point here is the "thorn in the side" of the whole plan... purchase price. But, lucky enough, you can usually find a bike sitting in a junkyard somewhere.

I'm sure this would be a great project for a modder to take on with a rear-ended car and junkyard access.

Come to think about it, I have a rear-ended CR-X Hf sitting in my dad's barn.. too bad its getting cut up come spring, and most of the rest of the car is garbage.

http://media.ebaumsworld.com/picture...d-rewinder.jpg
Must have been designed by the same guy.

^^^?

I like it!
 

I've been in the planning stages of something like this for a while. My ideas include: leave everything under the hood where it is--no hassle heat, charging system, brakes, etc; taper starting right after the B pillar--making the back seat just one place; drive the rear wheel with an electric motor.

I've got to believe 75 mpg using only the ICE and another 30-40 with the electric.

Aluminum Allow != Magnesium :thumbup:

They may be manufactured using the same/similar process - but that doesn't mean they were designed the same way.

I particularly like the plastic drum splash shield :) I wonder what the total cost was...

I'm well aware that aluminum alloy does not equal magnesium.. no rim is made of magnesium though, at least not entirely.

They're made of an aluminum alloy bonded with magnesium and other metals, hence the name "mag" rims.

You're right, they're probably different somehow. Except the fact that a bike rim can obviously hold the 700lbs of bike and rider while riding on the rear tire...

And the rear of a Geo Metro (especially a 3-wheeled one, even more especially if it's tapered back) DOES NOT weigh 700 lbs.

I fully agree that the forces on the rims for bikes and cars are very different, but the wheels for the weight need to be similar. there is less lateral loading on a bike tire, becuse the bike puts lateral load on a tire backwards compared to a car. at speed you push the bars opposite the way you turn, and the lateral forces are acting against the radii differences between the two tires at an angle. so you are pushing the trailing edge of the tire into the turn which is much easier than pushing the leading edge into the turn as with a car.

But if your worried about the lateral forces on the swingarm, I wouldnt be. because the rear is gonna wanna roll more than push. and if you want extra insurance on it, get either a supersport rear arm(WICKED beefy triangulated deal designed to resist twisting while "backing it in" under full power (3x what the metro has) and sliding sideways then regaining grip at 150mph.... I think it might be strong enough to resist the light end of a metro going 45mph around a turn) or get a touring/cruiser rear arm setup, those bikes weigh 700lbs pretty easily, are made entirely from steel, and all the weight is sitting on the rear wheel.

Alloying Mg with Al doesn't make the material Magnesium. Standard practice is to call an alloyed metal by it's base (exception for a few things, like Steel which uses neither the base or alloy).

I got to play with an X-ray fluoroscope awhile back... I found some chromium, zinc manganese, etc. in my wheels - but I sure as hell am not going to call them zinc wheels or manwheels and especially not chrome wheels :p :thumbup:

It's either an Al alloy or an Mg Alloy. You can alloy Mg into Aluminum, but it's still Aluminum. Mg just isn't practical for typical street vehicles, aside from their comparable lack of strength, porosity (probably better now than wheels of yore), etc. - you'll know when you see one when the firetruck just sits there while they burn :D

All that said - with respect to this topic... I doubt $1000+ was dropped on a Mg wheel while there's a gratuitous use of hose clamps, plastic barrel, plate steel in need of protection etc. That and the rust where the paint is chipped :p

Apparently, the 60's, 70's, and 80's muscle car/head era are lost on you...

Aluminum rims have been referred to as "Mags" for years. Hence the reason I keep calling them "Mags."

It doesn't mean they're magnesium wheels, it's just a name.

It's calling calling a fat guy "slim".. he's obviously not slim, but he's "Slim."

I still wanna see this three-wheeled Yamaha bike.

oopie, it's not a Yamaha, it's a Campagna T-Rex

Linky:
Campagna- Fun, Style, Performance

http://i146.photobucket.com/albums/r...006-726296.jpg

I don't think that's a stock bike swingarm.

The 60's, 70's and 80's can stay in the 60's, 70's and 80's.... Because something was done 20, 30 ,40 years ago doesn't show that it's done now. Industry has moved away because of stronger, nonflammable alternatives.

And, If it were just a name, why did you say
Mg wheels are Mg base alloys. Al wheels are Al base alloys. Calling it something else is inaccurate. Words have definitions to allow effective communication. Perhaps I'm anal about it - but attention to detail is my job :thumbup:

Why would this particular <very cool, I like it> three-wheeled contraption get better FE than the same Metro with 4 wheels?

Thinking out loud here, one less wheel bearing, and one less rotating mass, a little less overall weight <maybe>, perhaps less friction between the road and rubber contact patches <although, psi on the now single rear tire goes x2, so friction goes up by some amount, maybe 1.5?>. Is the sum of all that enough to where you'd expect an improvement of 20%-25% over an OEM Metro?

BTW, I love your electric single rear wheel idea, you'd just need to make the motor passive when engaging the ICE. Although still alot of work, the body mods you are talking about get easier if you aren't going to enter it into a car show... IMO crude is good enough to prove the concept, the 2nd gen can be 'purdy' :D

mizer: good thoughts, that's kinda where my enthusiasm to hack up my car lost it's momentum. My calcs showed less than 100 lbs weight loss, and I'd expect some reduction in rolling resistance simply due to the elimination of tire scrub on one end as the suspension works. But those factors, nice as they are, probably don't amount to a significant increase in fe... and they definitely amount to a significant compromise in utility.

FrankLee - might not be a stock bike swing arm, b/c they're not kit vehicles, they're actually jig-built and assembled in house.

I saw somewhere a kit to mimic it though, that used a swingarm and part of the frame of just about any street bike you wanted to use. The whole vehicle would cost less than $2000 to build, not including the cost of the bike you hacked apart to build it.

So, since you could get a bike for ~$2000, and the kit costs ~$2000 to build, plus random pieces/screwups, etc... figure about ~$5000... vs. ~$50,000.

But, I'm going to try to find some information on exactly how strong the average bike swing arm is.

I should have elaborated a long time ago, but IMHO there isn't anything inherently bad about using a bike swingarm and/or wheel on a trike... provided the vehicle is weight and traction and speed limited such that the light/re-applicated parts don't get overloaded and break or merely wear out prematurely. So yeah, even I'd be comfortable with that setup in something like a neighborhood NEV.

As noted, I had been thinking along the lines of a 5-passenger car application with little reduction in payload capacity.

THAT probably won't happen with a standard swing-arm... or with a standard car tire.

Even if you could reinforce the swingarm enough to make it work, you'd have to put stiff as hell springs on it to compensate for all the weight (3 people) that would go in the back... which means it would bounce when those people weren't back there, at least without some GREAT suspension engineering and leverage tuning.

That's not including the fact that one single car tire probably wouldn't be able to deal with the stresses associated with the entire rear end of the car, plus the 3 people sitting back there. You'd have to use a load rated tire, like those used on trucks and large vans. In that case, maybe using the actual car's suspension (reinforced, even) would be optimal.

Personally, it would be my perogative to build the swing arm to whatever specs I needed, for the vehicle I was using for the project. I most likely wouldn't use a "normal" part, unless I felt that it was safe to use, and would be optimal for the project. I'd also still most likely reinforce it, and use dual shock/springs, one on each side, progressive rate.

I would chance a guess at the beginning of the project to just use it the way it comes though, for the sheer sake of seeing if it would work. It's easier to envision what needs to be fixed AFTER it breaks LOL.

Good point, but the 185/75R14 tires generally have a load rating around 1300 lbs, which is enough.

I missed the fact that the 3 wheel metro pictured now enjoys motorcycle status.

It's been a long time since I owned a motorcycle, 1980 or so, here in California, the registration I paid for my motorcycles was a lot lower than my cars at the time. A savings of up to $75/yr on registration? In California, a motorcycle used to get away from the required for cars semi-annual emissions test, ~$45/yr. Insurance savings? Even if there is no FE avantage, There is potential saving you could use to buy maybe 3 months/yr. worth of fuel...

I don't understand why the designer went to all the trouble (and $) of making the Metro a 3-wheeler and then not finish tapering the body for better airflow and less weight overall.

My main concern with that mod isn't the weight or handling (the Metro's a Front-wheel drive with a decent amount of weight up front) but I hope he seriously reinforced the brakes on that single wheel as it now has three brakes total...:eek:

I hope the guy pipes up sometime with more details, driving impressions, fe, and whatnot. I admire that he went out and did it.

Yes, re: motorcycle status: there are a few bennies, like the lower registration. Also, you ought to be able to remove the bumpers, install plexi windows, and do things the gummint might frown upon if it had 4 wheels. Getting insurance on it could be a problem unless you simply keep car coverage. Er, in some states would you have to wear a helmet?

LOL.. You said "gummint". Win.

Technically, it wouldn't need bumpers, All the glass in the car could be replaced with Lexan or polycarbonate (it's not a car, it doesn't need safelite glass.)

You could throw most of the emissions requirement out the window, although not suggested.

Obviously, the owner opted to replace the rear floor with an access panel, which, quite obviously, could be made of fiberglass, carbon fiber, or any lightweight composite/material.

Weight savings occurs more than just with the obvious when doing this swap... my only concern is fuel tank placement... I believe that moving parts might interfere with tank placement on that vehicle, and most definitely would with a CR-X... so where's the tank?

Fuel tank is in the original spot. Look @ photo 3 - you can see the fuel filler tube going into it: Shutterfly

Always the observant one :P

Seeing where the wheel is placed, maybe it wouldn't interfere with a CRX's fuel tank either.

The CRX's fuel tank is almost placed like the Metro's is, right in front of the reinforcement that goes across the rear of the car, under the back seat. (The centerline of the wheel well is the rear-most portion of the back seat... the fuel tank is directly under the "seat" of the back seat)

If you only knew me during the PC Gaming revolution of the late 90's :thumbup:

Seriously, I am trying to get some information on why this mod was done to this car, but I guess it's up to the owner to do so.

The tapering I suggested (in all dimensions) starting at the rear edge of the B pillar would decrease the Cd, as well as some other body mods --like we talk about on every other thread-- belly pan, grille block, etc.:thumbup: