Another Nathan Armstrong interview

I lowered the wheel+tire weight of my tiny 500e by a full 12%, & noticed no difference at all in ride, handling or range*. Others with the same car have increased wheel weight with bigger rims, & the only difference they mention noticing is lower range.

*My wheels are lighter but less aero, so I likely get more city range & less highway range, cancelling each other out.

Measured acceleration & ride tests would almost certainly show a difference, but in normal driving it's not apparent.

Very interesting interview, a lot of gems in there. Some of my notes ...

• - Good insight into global strategy with regards to the three wheeler concept. (ie: three wheeler is a thing in the US market, but yet to learn what the regulators in other markets think about the idea and whether they want the car)

• - He seemed to avoid and pivot the question about where the energy goes in a crash. Maybe that was the editing? He could have mentioned that the reduction in mass means that there is less energy to deal with. He did mention that it’s similar to a motor cycle helmet, but he didn’t mention why that’s a good thing (Cars have crumple zones for a reason?)

• - Did he use the term “sprung weight” when he really meant “unsprung weight”? He didn’t seem to provide a good reason why Aptera‘s philosophy on sprung/unsprung weight is different to conventional thinking.

• - Discussion on motor cooling was interesting. (wheels have a motor coolant and return tubes going to each of the front outboard motors).

• - The idea of owners having the ability to customise the motor control does sound interesting, but they’d really want to get the sandbox right so people don’t accidentally fluff a line of code, the brake becomes the accelerator, and they then go out and accidentally kill themselves or somebody else. Sure, people modify ICE cars all the time, but is society (and the regulators) really ready for consumers to change lines of software in their EV weapon?

• - Loved the attitude towards backwards compatibility in both hardware and software. That’s a big ask and a complex paradigm to implement, because it means that you have to do a ‘futureproof’ assessment on much of the design ... but I reckon there is good value to the market and to them for doing it.

• - Interesting materials science discussion. That’s clearly his wheelhouse.

• - Not sure if it’s the way of the world in 2021, but I think he laid on the altruism a bit thick about wanting to spread the love. Nothing wrong with having ambitions to be a big car manufacturer to achieve economies of scale (and financial success). That’s what investors will want to hear.

0.09 because 0.9 Cd is like a weathered brick wall.

Yes, another great vid. He again mentions using the motors for ALL braking, currently being discussed on this forum if you click here.

He also clarifies the .09 drag coefficient as one they attained but deemed "too small" inside.

nathan’s enthousiasm is infectious. Some details about cooling of batteries and of the in-wheel motors (yes) and heat pump (not yet). Production schedule, composites, all interesting. As for the possibilities with the motors and controller, Nathan calls it ‘mindblistering’. Take that and run with it, I’d say to the advertisement department!

I wish Nathan would get a better microphone. He does these at his home, from which he has made several (and good) videos.