# Building a 3 wheeler



## moopups (May 12, 2002)

Plans are to acquire a shaft drive motorcycle, remove the swing arm and install a widened frame to attach a car rear end. This is to run errans, go to the feed store, ect.

The one problem to overcome will be the gear ratio, motorcycles turn their shaft about 6 times to turn the rear wheel once, however automotive rear ends turn their shaft at about a 2.5 to one ratio. There needs to be some kind of transmission before the rear end to regain the torque that will be lost. I am thinking of useing some kind of auto manual trans to accomplish this needed change, any one know of anything else that will fill the bill?

An auto manual trans will allow highway speeds when the engine is at an idle when in high gear, but will need to be in a lower gear for around town daily use. Suggestions?


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## WanderingOak (Jul 12, 2004)

Most custom trikes that I have seen use VW bug engines, rather than motorcycle powerplants. You are probably doing this for fuel economy, so I can understand why you aren't going that route. I believe Honda makes some factory stock trikes. Perhaps you could scavenge the rear axle from one of them out of a boneyard. Another option would be to use something like the transaxle out of a bug, and keep it in 4th gear for highway driving. That would also give you a reverse gear, which most motorcycles don't have.


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## Explorer (Dec 2, 2003)

"Meter Maids", the gals that enforced parking meters commonly rode three wheel cycles. Could you find and salvage?


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## DrippingSprings (Sep 22, 2004)

be extremely easier and cheaper to build off of a vw set up. After all unless you have a large displacement cc engine say a min 900 or bigger you will lose so much to weight that it will not get much better in the way of mpg and the clutch will wear extremely fast due to the extra weight its not designed for. 

heres what you really want anyway. They make bikes and trikes. They use small block and big block chevys. they have a trike with the rear of a 57 chevy and one with a corvette rear that have a 502 big block chevy 502 hp. 

http://www.bosshoss.com/products.asp?cid=97906693.976513.689277

If you have access to a small block chevy or ford or dodge you can build in the same way they do and use a stock rear end and just have to cut the shaft from the trans to the rear end down. You could always look in the local papers and find someone with a narrowed nine inch ford rear end cut to fit a vega etc etc that will work perfect and be narrow enough. Or you can have one cut for a couple hundred bucks.


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## mikell (Nov 8, 2002)

your in Flordia get a golf cart like everyone else we have to dodge down trere. Blinkers and brake lights and your in.

mikell


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## uncle Will in In. (May 11, 2002)

Put smaller lawn mower wheels on the rear.


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## Janon (Aug 25, 2002)

Geo Metro
Suzuki Swift
Pontiac Firefly
Chevy Sprint

All were almost identical vehicles, some/many had 3 cyl. Suzuki 997cc water cooled engines, and basically were motorcycle powered vehicles. The VW Bug by comparison had a 1200cc or 1600cc engine. The nice thing about the above listed vehicles is that they are readily available in various states of repair for low money, they are road worthy, cheap to insure and cheap to drive. Basically a poor mans 'Smart Car'. 

Building a motorcycle powered trike would be a blast, but custom fabrication of anything takes a loooong time - and usually more money than we initially think.

cheers,


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## DrippingSprings (Sep 22, 2004)

I saw a trike on a site today that had a v6 ford motor on it lol. Using either a bug powerplant and trans etc or any other front wheel type makes the going alot easier because you dont have to worry about a rear differential drive shaft etc set. anyone with any fabricating skills could rig up a front wheel drive motor on the back of a trike. All you have to do is rig the brakes fuel and shifter. If you can get an automatic your job is practically done for you.


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## moopups (May 12, 2002)

In that I am very advanced in metal craft, its going to be fun. I also make wrought iron house fixtures so all the tools, welders, benders are allready here.

Its going to be a truck type frame with about a yard square wood box with a lid in the back end. Leaf springs, car differental, trailer hitch, shielded lights, sort of an antique truck look.


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## John Hill (May 12, 2002)

I think you are right on the line with your idea of using a small auto trans in between the motorcycle drive and the rear axle and as noted elsewhere you get a reverse gear too. 

Of course if you are really going for the antique truck look you could use chain final drive for the required extra reduction.


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## Don Armstrong (May 8, 2002)

I feel uneasy about motor-trikes. They are no longer allowed to be sold in Australia because they proved unsafe. Far too easy to tuck the front wheel under on a slight downhill corner, maybe a small pothole, then they somersaulted end-for-end.


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## Esteban29304 (Apr 29, 2003)

Look what this guy did with a small diesel engine on a 3 wheel Cushman.
http://utterpower.com/cushman_diesel.htm


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## Ed K (Oct 24, 2003)

Moo,

Sounds like an interesting project. Sorry I don't have a ready gearbox solution for you. It does sound like a complex drivetrain.

Since someone suggested a VW and I have some experience with them (started collecting some scavanged parts) I'd like to mention that if fuel economy is the motive and you don't want 4 cylinders there are some folks who have made 2 cylinder engines by pulling off 2 cylinders and capping them at the block. and removing valves. You can cut the heads in half and the block too but you wouldn't really need to. Google "Carr Twin engine" and you'll probably findsomething on it. Don't be scared by the price of the kit to do it because it's for aircraft use and you wouldn't have to be as fance for a car/trike. 

Since you want a truck bed (presumably in the rear) you could consider the type 2 VW with flatter engine cooling tinwork.

A guy in my neighborhood used to have a Jimmy Dean style Porsche kit car. it had a VW engine that was converted to a mid engine. He told me all you have to do is reverse one gear in the transaxle and you can flip the transaxle over ad have a mid engine. That would get you a little more room in the back for your bed too.

Sorry for not helping directly with the question but with the 1/2 vw as someone said you'd have a reverse gear and better fuel economy than a std VW. Plus eparts are pretty easy to come by. It'll still give you lots of opportunity to fab just not so much on the drivetrain 

Good luck sounds fun


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## Esteban29304 (Apr 29, 2003)

This site is full of 3 wheelers, present & past. Some are interesting designs, & ideas, & some are laughable!! Takes quite awhile to go from A-Z.
http://www.3wheelers.com/ac.html


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## travis91 (Jul 26, 2005)

http://www.bobsokol.com/trike/ preety cool


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## Virg (Oct 3, 2003)

My errand getter is a 93 olds cierra automatic (100.00), 83 Honda 650 front,(200.00) and Maytag between em. Gets 30 and the wife loves it. Plus it hauls a tongue weight of 200 lbs. No wheelies. 10' long. The ecm and wiring was a bear tho. NFS. Virg


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## michiganfarmer (Oct 15, 2005)

you said the gear ratio in 3 wheelers is about 6 to 1. Most 3/4 ton trucks have 4 to 1 ratios, and can be fitted with 5 and a half to 1 gears. You might go that way too.


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## Janon (Aug 25, 2002)

Another option would be to use the front of a front-wheel-drive car as the rear of the trike. You'd have everything you needed to drive the trike, and would have the advantage of independant rear suspension. Any 3 or 4 cylinder front-wheel-drive doner car would do.

If you wished to use the motorcycle engine mounted mid-trike, you could remove the front-wheel-drive car engine (from the doner vehicle above) and mount the motorcycle rear wheel to the drive of the front-wheel-drive transmission. In effect, the transmission of the front-wheel-drive car would be the trikes differential. Most front-wheel-drive transmissions are mounted parallel to the front drive axles, which is what you'd need. Again, you'd have independant rear-suspension in the trike and a multi-speed rear differential (ala a big rig). 

cheers,


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## jakewade (Oct 18, 2005)

hey folks, 


buddy of mine is building a 3 wheeler . home made frame, 350 chevey w/ 3 speed tranny and a modified chevy rear end. trying to figure out what to use for the front fork. looked up some boss hog trike specs and they are talking about a " 63mm inverted forks, adj. preload 2.5" travel" front end . i'm a builder and know squat about bikes but i do use the computer and i've been to quite a few sites through google and still find no concrete info on what to use and where to get it. 

my buddy bought a front fork with a rim and tire but they seemed alfully light weight so we took a set of scales and found that bike and rider equaled a front end load of about 650 lbs. and the forty psi tire looked alfully "fatigued" by the weight. 

anybody out there know what to do here and maybe a "source" for parts. i believe he told me that boss hog wanted like $ 7 k for the front end/fork assembly.

thanks in advance for any help,

jake


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## Virg (Oct 3, 2003)

Jake, there's a lot more stress on the front than just weight. Going into a corner the side loads can cause the wheel to collapse sideways! And will. Get a BIG front end an weld the H out of it. My 650cc honda front has only a 500lb limit, not even close to what you need. Get the weight close to the rear as possible. My best handeling trike could be picked up by the front fender and swung around. But even then, after fast cornering one day I broke the axle and cracked the handelbars, "called tillers" Look up Brothers of the third wheel' site Good luck Thats a lot of power yer dealing with.


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## moopups (May 12, 2002)

Being that I am only in the planning stage of this project may be some one can answer this question. Clockwise or counter clockwise, which way does a shaft drive bikes shaft turn? Assumeing you are looking from the rear.

Same question conserning an auto differiental, still looking from the rear. And thanx for the sites mentioned, my needs are for an everyday use vehicle not a show piece. Basically a mini, 3 wheeled errand truck. A couple of hundred pounds capability. Something that hates the taste of gasoline!


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## Evons hubby (Oct 3, 2005)

I dunno about the rotation on the bike driveshaft, (I should, I own one) but the drive shaft turns counter clockwise on most cars that I have ever dealt with. As to simplifying your project, ever think about leaving the final drive of the bike in place and using it? yer gears would be matched up perfect for the engine tranny design, or ya could even go with a sidecar and not have to alter the bike at all. Good luck with yer project. =)


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