tadpole trike steering plans needed

[kriskros]

I can fin find pictures of tikes and see parts of the steering setup, but not enough to build.... my first interest is in the style the uses a single U shaped steering arm under the seat... not the double cross link type.. I need a plan tht can give me clear idea of the layout and hopefully some dimensions.. setup would be for 20" wheels with disc brakes.. other types of steering ideas would be also be VERY welcome.. this will be going on a wood frame trike.... making a wood crossbeam connection between the two wheels I can do..thanks

 

[xenodius]

Not tadpole, but jetrike.com is absolutely inspired-- Henry Thomas is a mechanical engineer, I believe. Anyway, super detailed plans and he accounted and tested for every conceivable vehicle characteristic... and came up with an exceptional design I someday hope to follow somewhat closely. My only additions... front suspension, fixed BB/"electronic" transmission, underseat batteries, rear rack, and full fairing + canopy. And most likely with flexible solar panels pasted onto the fairing before finishing... hopefully that dream happens in this decade. =)

 

[kriskros]

many thanks everybody for the usefull info...I should be able to find a couple of ideas that I can use

 

[docnjoj]

Check out Horowitz plans. they were some of the most well engineered one's for Tadpoles in the last 10 years.
otherDoc

 

[jateureka]

The TerraTrike Tour II user manual has some drawings of the steering and seting it up & the Dealer Manual has some black & white photos.

http://www.terratrike.com/manuals.php

 

[mat h physics]

So if a tadpole trike had a full fairing, tail included, could it act like a wing drawing/pulling to the inside of the turn. The rear wheel would have to have rotational freedom to remain perpendicular to the direction of travel, "steering" in the sense of actuation not necessarily change of direction.

This may be more of an adv topic on steering force, but an interesting hypothetical.

 

[llile]

Take a look at my build of a trike with two front motors.

Don't ever fool with rear wheel steering - most experimenters who have tried this have hated it. A rear wheel steered vehicle has to veer left into the traffic lane to make a right hand turn - very bad. Front wheel steered tadpole trikes are very practical.

This treatise (referenced in my build) is the best online resource for trike steering and other trike geometry issues. Study it carefully. You can implement a good steering mechanism with tillers for steering, and a properly placed tie rod. No need for complicated underseat steering or indirect mechanisms. A tiller just bolts onto the steering axis and has a handle on it, a place for brake and gear levers. That's all you need.

Build a mockup out of scrap conduit or cheap pipe. No need for it to be really rideable - work out geometry, angles, seat heights, chain lines

Start with a simple frame - vertical front steering axis (not ideal because they bump steer, but really simple to build), Ackerman tie rod geometry. Look that up in the HellBentCycles reference cited above.

Then build a jig - a sturdy frame out of wood or better square steel stock, that you can anchor parts on for welding up your frame. You should spend as much time on the jig as you will spend welding the actual bike frame. A trike is a three-dimensional steel sculpture, and it is extremely difficult to get it all lined up with itself if you don't have some reference to start with.

 

[llile]

Completed Trike


Me and a buddy on ttwo motorized E-trikes

 

[llile]

I'll try to post some more detailed pics of the front end soon.

My buddy just bolted the tie rod onto the bike, and used the bolts as a tie rod end. I went one step farther and bought good tie rod ends from anaircraft supplier

It is better to have the front steering axis project onto the ground in front of the front tire, which makes your front tires attempt to run straight. This is less important on a trike than a bike, which can be almost unrideable if you skip the caster. Trikes are actually rather forgiving.

The tie rod bearings should be on a line between the front contact patch and the rear contact patch. This is called Ackerman tie rod geometry, and helps you corner.

Keep the whole mechanism as simple as you can for your first build.

Be careful about rear wheel alignment. A very slight error in rear wheel alignment can cause the bike to pull to one side or another.

I would recommend a single rear motor for the first go, my crazy two-motor beast is not a good idea for a first build.

And go to an auction and get a whole pile of old bikes of almost any flavor. Cut them up for parts, you'll need several.