That is it for Aptera

[cfg83]

Frank -

Originally Posted by Frank Lee

...

Don't be too in awe of what Aptera did for the body; that was directly lifted from Morelli's work:



So, somebody was sitting around over beers and decided to adapt the lowest drag body form possible for street use. Great idea, if only they'd picked a development team with some experience.

I know I've seen the Morelli shape over the ears, but I never made the *obvious* connection. I can't remember if the v1.0 Aptera website stated this or not (the v1.0 website had more information than the new-CEO version).

CarloSW2

[cfg83]

Neil -

Originally Posted by NeilBlanchard

...

But some of the details are not quite correct: the front wheel drive was a decision by the original management, and there were very good reasons for this. They strayed big time by insisting on full roll down side windows (instead of partial openings). This necessitated a complete reworking of the doors, and the chassis, and the weight was increased, which then required a bigger battery pack, which then moved some of the cells to the rear floor, which shifted the Cg -- and the original efficiency was transformed into a very average EV.

...

Were the pre-roll-up window prototypes road-tested? Did they have stability problems?

CarloSW2

[euromodder]

Selling the high-MPG-at-some-cost-and-annoyance side of things will be bad enough, so no-one needs to design a weird looking vehicle like a 3 wheeler.

There's nothing wrong with having 4 wheels, even if it adds some drag and weight.
The rewards in stability have proven the 4-wheeled concept over and over.

[Frank Lee]

I think the trike layout can have advantages for one or two passenger side-by-side vehicles, but handling deteriorates quickly when loads in addition to those in a front seat are placed near the single wheel.

[Ken Fry]

Originally Posted by cfg83

Frank -

I know I've seen the Morelli shape over the ears, but I never made the *obvious* connection. I can't remember if the v1.0 Aptera website stated this or not (the v1.0 website had more information than the new-CEO version).

CarloSW2

No, they didn't state that connection, and strongly implied that it was their design. Within a month or two, people were pointing out the fact that it was the Morelli design. They also quoted a .06 Cd, and talked about development via CFD -- but CFD on that shape with wheels would not have produced .06. The .15 they claimed later would be closer, if they had all the details right.

[Ken Fry]

Originally Posted by Frank Lee

I think the trike layout can have advantages for one or two passenger side-by-side vehicles, but handling deteriorates quickly when loads in addition to those in a front seat are placed near the single wheel.

Although if the vehicle is light (granted... Aptera made a stab at handling this through redesign -- they just made the thing 3 times as heavy as first announced) then the side-by-side seating makes it handle like a motorcycle with a side car, with different right turn and left turn dynamics when one person is on board. The Aptera was so fat, that the driver was fairly close to the line between the left front and rear contact patches. Combine that with high CG and incorrect geometry, and you can expect poor handling.

Stiff suspension and low CG can help with this stuff.

[Frank Lee]

I know they wanted to stay out of ground effect and that's why it's so jacked up, but the Morelli shape was tested without wheels or anything between it and the ground plane. Simply adding wheels and their fairings and the struts must have had an effect on the flow all along the bottom and even lower sides of the body, such that I wonder if the ground effect aero was so disturbed by those things, that they could have just lowered it to a height suitable for handling anyway without incurring any further noticeable aero penalty.

I know they stiffened the bejeezus out of the springs at the X Prize competition in order to pass the slalom test. I wonder what the ride quality was with those springs? Even with that extreme front track width and stiff springs, those arm angles and CG look like deal killers to me.

[NeilBlanchard]

The lowest Cd number I've seen associated with Aptera is 0.11. The front wheel drive versions had 0.15.

The pre SO-1 versions did not have stability problems, or at least the PP range of prototypes did not. The Zen model with rear wheel drive was quite a bit taller, so it may not have been as stable.

The PP-6 or so was the best of the bunch:



Goin' with the Flow: Aptera 2e - Gallery

[Ken Fry]

Originally Posted by euromodder

Selling the high-MPG-at-some-cost-and-annoyance side of things will be bad enough, so no-one needs to design a weird looking vehicle like a 3 wheeler.

There's nothing wrong with having 4 wheels, even if it adds some drag and weight.
The rewards in stability have proven the 4-wheeled concept over and over.

Actually, there is no intrinsic benefit to three wheelers for drag reduction. If you make the three-wheeler fat, (Aptera style) there is no benefit at all. You have to at least put the people on centerline, (or near, as in Doug's idea) to dramatically reduce frontal area.

Despite Aptera's claims to the contrary, three wheels do not have less rolling resistance than 4. Rolling resistance is a function of weight and Crr. Three wheels with 333 lb on each have the same rolling resistance as 4 wheels with 250 on each.

There is a slight advantage in parts count to three-wheelers.

The real disadvantage to four wheels is that you are then a car, and are playing in a market where a $billion to develop a single new model is standard, and Aptera's 24 million in funding is a rounding error. You can expect to spend millions in crash testing.

Three-legged stools are more stable than four-legged stools. Camera tripods are tripods for good reasons. It's just a matter of engineering a three-wheeler to work right, as Morgan did in the 1930s. The T-rex out-handles a Porsche. Jay Leno raved about the modern Morgan Three Wheeler.

[kach22i]

I remember way back when I first saw VW Rabbits and Mini's racing. They were all 3-wheelers in the turns.

http://www.red4est.com/lrc/racer_html/racecars.html


Swiftune at Goodwood