Learn Me: Tilting reverse trike

I have been toying with the idea of building a reverse trike (two wheels up front, one in the back). My original idea was to find a crashed sport bike to donate the engine and rear suspension, use a VW torsion beam front suspension and build a tube-frame to join them together. The other day I came across the Mercedes Life-Jet Concept and think it would be awesome to incorporate a leaning suspension into the car. My new idea is to build a double wishbone front suspension and use air springs for the suspension and to control the lean. The air springs would be pressurized by an engine driven air compressor with a tank. I would use a gyroscope like those used on model helicopters to control solenoid valves to dictate the lean of the vehicle. This should make the body lean as much as necessary to eliminate lateral forces on the “cockpit” (think a pendulum hanging from the rear-view mirror; it would always hang straight down). Thoughts, criticisms, ideas?

Life jet: http://www.conceptcarz.com/vehicle/z964/Mercedes-Benz-F300-Life-Jet.aspx

http://www.youtube.com/watch?v=AOfuAjXP4cs

You could become the next Liz Carmichael.

http://www.onehellofaneye.com/2010/04/26/don%E2%80%99t-take-those-boobs-to-town-boy/

I don't look very good in drag... Too much beard.

Less tilt.

IndyCycle.

Can-Am? (That's the trike, not the road race series.)

Can-am doesn't tilt.

but the VentureOne Carver does:

wearymicrobe wrote: Less tilt. IndyCycle.

Very cool, I hadn't seen that one before.. Those are some wide wishbones on that thing!

Wide track, no lean, I think.

My concept for this would be a BMW K12LT engine/transmission/rear end (with reverse) mated to a Miata front end.

Grtechguy wrote: Can-am doesn't tilt. but the VentureOne Carver does:

am I wrong in saying I want one of these?

There is not sufficient Grinnall Scorpion in this thread.

werf one fousand quid!!!1!

and...well, heres this, for no reason really, just because it came up in my search...

I went to Canada for the F1 race a few years ago and I saw two different T-Rex's driving around the streets of Montreal. Very cool.

^Naw kitteh likes boobies too

Protip: It's possible to create a "carving" suspension that's purely mechanical and requires no active power. I don't know how to set one up but I've seen the concept demonstrated on a little go-kart. Might want to research that.

T-Rex = teh sex

bgkast wrote: I have been toying with the idea of building a reverse trike (two wheels up front, one in the back). My original idea was to find a crashed sport bike to donate the engine and rear suspension, use a VW torsion beam front suspension and build a tube-frame to join them together. Thoughts, criticisms, ideas? Life jet: http://www.conceptcarz.com/vehicle/z964/Mercedes-Benz-F300-Life-Jet.aspx http://www.youtube.com/watch?v=AOfuAjXP4cs

Since your title mentions titling, it might help to mention what state you are in.

From what I understand, as long as you are willing to follow your state's respective motorcycle laws (i.e., helmet), it's usually a lot easier to title a home-built motorcycle than a home built car (I think it's assumed a motorcycle has no safety features...)

GameboyRMH wrote: ^Naw kitteh likes boobies too Protip: It's possible to create a "carving" suspension that's purely mechanical and requires no active power. I don't know how to set one up but I've seen the concept demonstrated on a little go-kart. Might want to research that.

I have seen a few home built vehicles that use a mechanical tilt setup coupled to the steering. The issue I see with that type of setup is low speed sharp turns (like a u turn) and counter-steering if you ever go into a skid (the vehicle would lean in the wrong direction and would tend to roll over).

Do you think that the benefits of a tilting suspension setup are worth the complexity and additional weight or would I be better off building something with more typical suspension?

In a reverse trike setup I'd say it's not worth it. A reverse trike's handling is closer to a 4-wheeled car than a conventional trike.

davidjs wrote: Since your title mentions titling, it might help to mention what state you are in. From what I understand, as long as you are willing to follow your state's respective motorcycle laws (i.e., helmet), it's usually a lot easier to title a home-built motorcycle than a home built car (I think it's assumed a motorcycle has no safety features...)

I am in Washington state. I have read that this state only Considers it a motorcycle if you straddle the engine, and but I have not been able to find the applicable currency law. I plan to talk with the vehicle inspection office before I get too far into the project. I also think it would probably help to keep the bike frame intact enough to maintain its Vin.

In reply to fastEddie:

That looks like a fun toy.

bgkast wrote: I am in Washington state. I have read that this state only Considers it a motorcycle if you straddle the engine, and but I have not been able to find the applicable currency law. I plan to talk with the vehicle inspection office before I get too far into the project. I also think it would probably help to keep the bike frame intact enough to maintain its Vin.

Washington RCW 46.04.330 "Motorcycle" means a motor vehicle designed to travel on not more than three wheels in contact with the ground, on which the driver: (1) Rides on a seat or saddle and the motor vehicle is designed to be steered with a handlebar; or (2) Rides on a seat in a partially or completely enclosed seating area that is equipped with safety belts and the motor vehicle is designed to be steered with a steering wheel. "Motorcycle" excludes a farm tractor, a power wheelchair, an electric personal assistive mobility device, a motorized foot scooter, an electric-assisted bicycle, and a moped.

Here are a couple of dedicated resources where you can use to start your research:

Tilting Three Wheelers

Yahoo Tilting Group

The main problem that you will be facing with a tilting reverse trike is that your steering can not be directly linked to your tilting...That and depending on which route you go, the need to switch from counter steer to simple steer at very low speeds. You either need sophistocated electronics, to rely on physics for one of them, or to give the driver an additional variable to control. The easiest would probably be a "free to tilt" system that would pretty much ride just like a motorcycle and require a certain amount of balance, but could also incorporate a tilt-lock for low speeds like the Piaggio MP3. However another option being explored by a few individuals is "free to caster" where the steering functions more like riding a bicycle with no hands, just with the added ability to force the lean angle more rapidly thanks to the dual front wheels. And then of course there is providing the rider (driver?...pilot??) with the extra control function to independently control both tilt and steering, as seen on the Brudeli Leanster.

Attempting to build a tilting 3-wheeler is a big departure from 4-wheelers and non-tilting 3-wheelers, that will require an entirely new learning curve.

Great information, thank you!