Delta Vs Tadpole

[kach22i]

September 9, 2015
Engineering a 3 Wheel Vehicle Chassis
https://engineerdog.com/2015/09/09/e...hicle-chassis/

For EngineerDog readers I wanted to share my favorite section of the instructable, a unique perspective on three wheel vehicle dynamics: My answer to the question, what are the advantages/disadvantages of having two wheels in the front instead of the back on a three wheeled vehicle?

To answer this, we need to first define the two different vehicle layouts and compare them for a few different vehicle performance characteristics:

Delta: One wheel in front, two in back.

Tadpole: Two wheels in front, one in back.

I don't typically see Delta or Tadpole used as terms usually, normally it's Trike or Reverse Trike.

However, I think this article is good in many ways.

If you are into the math, there are several other links and PDF's at the bottom of the blog.

[Frank Lee]

More than one opinion on it:
https://www.rqriley.com/3-wheel.htm

Welcome to VIGILLANTE'S Page 2

[Stubby79]

I've seen "Tadpole" used often enough in the bicycle world to differentiate from a "regular" trike. Since they're "regular", I only rarely see them referred to as "deltas".

[Ecky]

I ride a tadpole to work when the weather is good:

[kach22i]

Originally Posted by Frank Lee

More than one opinion on it:

Welcome to VIGILLANTE'S Page 2

Quite the history on that car, going back to the TriVette 1974.

Looks like that is the same route Nissan's DeltaWing takes.

If I understand correctly, it's basically a Segway with a front wheel to transfer torque shift under hard braking.

It's configuration, that is to say wheelbase is outside of normal 3-wheel parameters.

I would not want to parallel park one of those.

The other link is what I regard as a very nice design, the Riley XR3 Hybrid looks to be quite an improvement over the older Tri-Magnum design.

Originally Posted by Ecky

I ride a tadpole to work when the weather is good:

You finished it............looking good.

[Frank Lee]

I don't subscribe to one being inherently better than the other. Each has pros and cons and each can be made to excel on the street.

I have driven numerous examples of deltas though, and have yet to sample a motorized tadpole... except for the swather on the farm.

I bet that Deltawing, if reconfigured to three wheels, would still excel.

Top Gear's slanted Reliant piece is more about entertainment than how awful deltas are, but then the Reliant is not an example of a properly engineered delta even when it isn't sabotaged for tv.

[kach22i]

Originally Posted by Frank Lee

I have driven numerous examples of deltas though, and have yet to sample a motorized tadpole... except for the swather on the farm.

I haven't driven either type of three wheeler.

Makes me think how much I may be missing out on.

The difference between reading about hovercraft and actually trying to get one up over hump speed for the first time is enormous for example.

[Ecky]

I found I had problems with center of gravity until I relocated by batteries to the floorpan - it was far more prone to tipping than an equivalent 4-wheeler.

Two wheel steering is considerably more complex than single wheel, but driving two wheels in the rear is more complex than a single.

[Stubby79]

I've only had one or two rides on my recumbent tadpole trike under power assist. It helped, seeing as how slow I could only get it going under my own power. But it didn't do anything for the other issues...like how awkward the under-seat steering is, and how harsh the ride is.

Now that I have lithium batteries of the right voltage - and nice and light - I might have to try again. There was no point to trying to lug the thing through doors with an additional 25 pounds of lead strapped to it. Fitting through doors is another issue. As are the scrawny tires that I popped two of in the first week with it. It turned out to be one of those ideas that was better on paper or in my head than in reality.

It's time to get back in to cycling....I think the weather today will let me get out for the first time in weeks.

[Frank Lee]

http://ecomodder.com/forum/showthrea...ink-35341.html

I have a suspicion we haven't heard more about this due to scary handling brought on by the built-in rear weight bias.

P.S. I'd wager if those a-arms were flipped or switched left to right to move the front wheels back a few inches the improvement in stability would be noticeable.