Another stupid question

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On tadpole trikes etc. seems like a lot of the work is getting the two front wheels mounted with steering etc. so dumb question why not just put them on a solid axle and pivot the whole axle in the center to steer? I could see why not on a car weighing a few thousand pounds but a pedal driven trike has a lot less stress on it. Am I missing something?
 
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if you had a solid axle you could not negotiate a curve very well or the trike would tip over.
Steering as per the plans is easy to build. one days work.
 

Radical Brad

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What you are describing is called "tiller steering", or rightfully, "killer tiller"!
You will only see real examples of this in two places; kid's 2x4 go carts, and ancient horse drawn carriages.

Every possible thing is wrong with tiller steering, from bump steer to center of gravity shifting.
Imagine hitting a curb with such a beast! You would sheer off your leg as the scissor like assembly folded on you!

It is not a stupid question at all! The only stoopid question around here might go like this...

"What are the Caradshians doing today on TV"?

or

"Where can I buy a ready made custom bike or hot rod"?

Brad
 
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build a delta ...

problem solved..

I'll get my coat ..
 
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Good suggestion on a Delta but a Delta has it's own issues.
Yes easier to build but stay away from a solid axle in the rear unless you like to hobble some going around corners.
Then you must get the fork angle correct for the trike. Not a exact science. Built several and both do not handle the same.
Purchase a set of plans then start having fun building your one of a kind creation.
 

Twinkle

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Weren’t the Cardashians on Star Trek?

Just asking to learn why some things are done or not done
Strange question to ask on a trike builders forum ,
I heard they emigrated and were last seen hitching a ride on the rear of a sheep in Wales ( but that is another story )

but

If you want to fit a solid rear axle , I did on the quadem ( quad tandem ) project but I fitted a 20mm free hub ( with disc rotor ) at one end of the 20mm shaft I used with 20mm HD pillow blocks . This project used only 2 supporting heavy duty pillow blocks and worked well with us two lightweights ( conbined weight 330 lbs ) pedaling along .


You can also get 15mm free hubs if you don't have a gravity inducing problem .

For the reason you don't drive both wheels on a fixed axle I suggest you google "differential "

reagards emma
 
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I understand differentials on a rear axle I was asking about a front swing axle. Not that I was thinking of doing but why it isn’t used, etc.
 

Twinkle

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On tadpole trikes etc. seems like a lot of the work is getting the two front wheels mounted with steering etc. so dumb question why not just put them on a solid axle and pivot the whole axle in the center to steer? I could see why not on a car weighing a few thousand pounds but a pedal driven trike has a lot less stress on it. Am I missing something
?
It's all a question of balance or rather stability.The pivot point would also have some odd forces acting as side and twisting forces that would make steering very hard .

Building the front end of a tadpole can be done by jigging it on the bench and welding it all together before mounting it on the main boom.
 

Radical Brad

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I finally found an actual example of killer tiller to demonstrate...

2823

This is a nicely done kid's cart that is steered by feet on the tiller bar and by holding the rope.
For a simple and ufun kid's gocart, no problem, but never do this kind of thing on any vehicle made for speed or street use.

Just imagine what a slight kissing of the curb would do to you at 30 miles per hour!
I can imagine a scenario that involves a front flip, lost toes, and then a trip under a bus.
.... of course, you should be THAT paranoid anytime there is bus behind you on a bent.

Brad
 
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You could also google Ackerman angles. You don't get Ackerman angles on a tiller steered cart. Both front wheels point the same way in any turn despite the inner wheel tracing a smaller circle.
 
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