Sociable Tandem Recumbent Electric Hybrid Tricycle
Tandem Electric Hybrid Recumbent Trike
By Warren Beauchamp
5/08/08
I have been riding the electric bike to work a couple times per week for the past month or so. Often it's raining or too cold. I'm thinking about an all weather 2 seat side by side electric tricycle. I saw a tiny Saab Sonnet 2 seater sports car on the way home from vacationing in Wisconsin, and I can't imagine that this vehicle would be much smaller.

Vehicle law says that a three wheeled vehicle can be licensed as a motorcycle. This means that I could build a relatively lightweight pedal and electric powered vehicle, that could legally run at high speeds, while using the rather lenient motorcycle specifications.

I'd really like to make something with a slick body, which would require a custom frame. I'm thinking something less than 4 feet wide, and probably 9 feet long.

The body would be mostly Coroplast, and the widows would be Vivak plastic, except for the front windows which would be "AR". That stands for Abrasion Resistant. It is essentially Lexan (Polycarbonate) with a scratch resistant coating applied to one or both sides.

It is available through Piper Plastics in Libertyville, IL.

Side View
For crash protection. I'm thinking several layers of 2" foam in the front and rear, Plus 1 layer of 2" foam in the doors. It's not much but it will operate using the same principle as a bike helmet.
5/19/08
Top View
This fully suspended vehicle would use light duty motorcycle wheels and brakes and a tube steel frame with roll bar. The doors would open in gull wing fashion to allow easy entry. Windows would be plastic.
Because this will be a relatively large and heavy vehicle (200 lbs with batteries?), it will need a fairly powerful motor. Maybe something like this 5000 watt hub motor for $750?.

5/18/09
I saw this 1970 Ferrari Modulo concept car  and thought of this project. Everything is very flat panel oriented. I especially like the method of opening the canopy, and think that would be easy to build and work well for this application.
8/1/10
Though I have not started building this vehicle yet, I continue to think about it. Because this vehicle is designed to compete with cars on the road, it will need to go faster than the now federally mandated 20 MPH maximum speed limit for electric assist vehicles. In my opinion a two person wide vehicle that will operate on the same roads as cars would need to be able to operate at up to 40 MPH to ensure safety. Any slower than that and it has the "rolling road block" effect.

Because of this it will need to be licensed as a motorcycle. To license a vehicle as a motorcycle, it can't use any bicycle parts in the frame, suspension, or wheels, and the tires must be "DOT certified". This increases the weight of the vehicle because it now needs to use much heavier motorcycle wheels and brakes.

Fortunately, mopeds use DOT certified components, and are lighter weight than traditional motorcycles. One option is to find two identical used mopeds with large wheels. I could use the two front wheels and one of the rear wheels with suspension swing arm. I would need to build a custom frame with front suspension, and adapt the moped drivetrain. Another option os to use new parts, such as these DOT approved 17" wheels available at www.electricmotorsport.com

The front suspension could be either a MacPherson strut arrangement using a single lower A-arm and a single leg of a motorcycle front shock for the strut, or a more complicated inboard suspension with the shock units in the center of the trike. The inboard shock system would allow more leg room, but be heavier and more complex.

More thoughts on frontal and rear crash protection in the far front and rear sections of the body - fill them with grocery bags full of packing peanuts.

10/01/10
Time goes by, and I continue to think about this. I have decided don't want to build a car. I want to build a two passenger all weather e-assist trike out of bike parts. This ensures it stays light and inexpensive to build. It also means I won't be able to legally get away with running down the road at 45MPH. Because a slow moving sociable tandem is a rolling road block, I will have to abandon that approach, and instead refocus on an in-line tandem. This will allow cars to pass without an undue amount of road rage. I still want it to be e-assist, but now it won't have to go so fast.

My latest thought is to use a SteinTrikes MadMax EVO front end with a non-suspended rear wheel, and big long tube in between to support a second rider. Add a narrow body away we go.


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