Three wheel steering

JennyB

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Northern Ireland
Thinking about the simplest, lightest vehicle that would be usable on any road, with a low frontal area and a bit of streamling for maximum range. Hand controls only.

I was at first thinking of something like a racing sidecar combination, but that has a problem of asymmetry: even with a helpful passenger, it's a lot easier to corner with the chair on the outside than the inside. So I end up with a delta trike, batteries between/behind the axle, open tray in front in which you sit and to which you strap your luggage. But three track are a problem on narrow lanes with grass growing down the middle.

So, what if you could steer ghe rear wheels so that the front could run in line with either of them?

Just a thought....
 
What do you mean by smallest, lightest and hand controls?

Are you talking about hand pedals or a twist and go scooter style of drive?
 
JennyB said:
So, what if you could steer ghe rear wheels so that the front could run in line with either of them?
Do something like Steve Roberts did. Build a two wheel bike like normal. Then have outrigger wheels you can drop when you need more stability.
 
Martin A said:
What do you mean by smallest, lightest and hand controls?

Are you talking about hand pedals or a twist and go scooter style of drive?

The latter. As to size, no more than 8' long by four wide, and capable of carrying anything a longtail cargobike can. I'm thinking that for really bulky loads and awkward spaces it could function as a powered handcart or trailer. Just something slightly more all-round useful than a scooter.

I'm rising 63, haven't driven a car for over two years, and have no desire to start again, but my cycling days may be numbered. I had an accident at the end of February that strained my knee ligaments, and I haven't fully recovered yet.
 
If you dont plan to have a manual pedal drive system, and only use hub motors, it could be engineered , but still a complex multi-jointed system.
For wheels to run in mainstream auto wheel tracks, that will require a very wide track trike ...4.0’ or more.
So quite a sizeable machine,..and with increased complication and size comes weight and restricted convenience.
A big tradeoff for those grass tracks !
 
It seems plausible to attach a steering linkage (like that of a Long John bike) running from one side of the fork, under the bottom of your trike, to a longer lever in back, steering the rear wheels in the opposite direction.

You will want the rear wheels to steer through a much smaller angle than the front wheel-- maybe 1/3 or so?

You can make this work with forks and headsets, or with stub axles. Chassis stiffness and integrity are better (all else equal) with stub axles, and you can have more room for payload that way. But making the thing is probably easier with forks, and normal front hub motors are way easier and cheaper to come by than stub axle hub motors.
 
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