Comment by Aurornis

I'm more fascinated by the question of whether it scales up... imagine much smaller and more efficient electric engines for cruise liners and cargo ships.

That can be offset by not requiring the same sort of range that's typically assumed to be required.

While I'll be likely be riding my ICE bikes for decades because one of the things I do on them is trips with 1000 or 1500km days, truth is the vast majority of my riding is sub 25km round trips from my place. Most of my friends places, a lot of the places I shop or socialise, and the office (which I pretty much never go to any more) fit inside that range. And most of those trips take place on roads with a 60kmh or slower speed limit. _Maybe_ a few short sections of 80kmh.

For all of those short trips, I probably don't even need 2kWHr worth of battery, maybe only 1. The electric motorcycles available around here seem to start at 7 or 8kWHr, and go up to over 20.

The downside to that is the smaller the battery capacity, the smaller the short term peak power it can deliver. The sort of cell chemistry and construction typical in those sort of bikes seem to be limited to 10 or 15C peak discharge, so while their 8kWHr battery can peak at 80kW or just over 100hp, if they downsized the same pack to 1kWHr it'd probably only deliver 10kW peak power.

On the other had, alternative cell chemistry and construction can look way better. I have a few LiPo drone battery packs rated at 60C continuous and 120C peak. A 2kWHr pack of those would give me 120kW continuous and 240kW peaks. Quite likely though at the expense of much greater risks of catastrophic fire. I've had a few of those pack catch fire while charging and one that self combusted in an almost explosion like fashion when I slammed the drone into a concrete pole at about 120kmh. I can totally see why an electric motorcycle manufacturer with warranties and safety reputation and legal/regulatory obligations wouldn't want to accept that risk.

I'd love an electric motorcycle that's "fun" enough to ride, and gets 25km or so reliable range. But it'd need to be at least a bit price and "fun" competitive with my little bikes, a 117kg 125cc ~25kW two stroke and a 138kg 250cc 24kW fourstroke. I have no doubt it'd be possible, perhaps even easy to build an electric bike with the same "fun" power to weight ratio, but right now not down to the sort of price that'd make me take on a project like that.

Indeed, more so because that weight tends to be further off the ground than in a car.

Ten years ago it was a problem.

Good, even some great, stuff out there, today.

They are not allowed, but still commonly owned and used.

The law needs to catch up. There are clearly good reasons for people to want extremely powerful e-bikes and they should be allowed to. They can't be treated like bicycles because they're too fast but aren't nearly as dangerous as motorcycles. We need a new category for light motorcycles.

The real problem, IMO, is that the law is generally not deferential enough to cyclists and already forces them off sidewalks, onto the street, and to follow traffic laws designed for cars. There's not much else to take away, and the rules right now are unreasonable enough that cyclists always break them.

I think what I would like to see are explicit requirements for insurance and licensing for powerful e-bikes, but made significantly cheaper so that people will actually bother. Requiring helmets for the insurance would also make it much more straightforward. We can require them to take the street or a dedicated bike lane and fully mandate that they have to be walked on sidewalks.

There is a big issue in the US currently with people buying electric motorcycles that look like e-bikes.

Okay, but is it difficult to extrapolate the weight saving benefits of a "legal" power e-bike motor?

He said motorcycle. That's a market of hundreds of millions to one billion customers.

Oh nooo i have to put a sticker on it, and only allow my control to go to some arbitrary value when the cops are watching

Listen, your world may not allow you to sell an e-bike with a 1000hp motor on it. But my world allows me to put a 1000hp motor on an e-bike and not tell anyone.

Now hold my beer...

Exactly this, which is why I'd expect automakers to use the short axles and CV (constant-velocity) joints which are already well-developed technologies for 4-wheel independent suspensions

I see no reason the small motors can't be mounted inboard from the wheels on the underside of the chassis, as are a rear differential or front transaxle in an ICE car.

Having such a small and lightweight power package opens up serious design and performance opportunities. Plus, even without major redesign to take full advantage, every reduction in weight rolls through the system, providing immediate improved acceleration, cornering, & braking or similar performance using smaller tires, brakes etc..

Yes, I agree. I was careful about how I worded this to avoid saying anything about the motors actually being in the wheels for this reason.

Although, I guess at some point in the future if we can get the weight down low enough and the strength of the motor high enough we could replace the existing braking system with a motor for the same weight penalty we already pay.

In an ideal world all the energy from breaking would be used for regen anyway.

I'm not sure how close we are to that but it's an interesting thought experiment thinking about the trade offs we might be able to make in future.

If the motors are light enough, though, that might be acceptable... especially if they can make an even smaller version for that application. (You probably don't need 750 kW on each wheel - even for a supercar that'd be excessive.)

Maybe fine for non-performance vehicles, especially considering you can remove driveshafts and brakes.

But these are 28lbs which isn't a lot to have in the wheel. Considering that this is the 1000 HP version you definitely don't need 1000HP in each wheel, but maybe they could come up with an even lighter 100 to 200HP version?

I don't think they mentioned that it would be inside the wheel. One motor per wheel could just mean two motors per axle.

I'm at 115,000 km, at 133 Wh/km since the last (inadvertent) trip reset. The previous one (for the life of the vehicle) was at a similar number.

This is on a 2022 Long Range Model 3.

That’s still around 2 km per kg of batteries.

Nah, the main thing is that electric motors are already far better than they need to be -- even assuming the claims are all true, it would only make a small difference.

Shaving a couple percent off the total vehicle weight would still be a very good thing, but improving batter energy density by 10% or so would be a bigger deal for most EVs.

There might be some niche applications where the battery weight isn't the biggest issue -- like very short-range, light-weight vehicles that need to have enormous amounts of power for some reason.

I could see motors like this being used in power tools if they can be scaled down. A light-weight plug-in electric chainsaw would be pretty awesome.

I'm not reading anyone's marketing material. If you want to dispute the shipping weight, feel free to correct this website whom I assume charges for shipping based on weight [0]. I'm sure they'd love to know they have it wrong.

According to purchasable equipment, the Model 3 engines weight ~175 lbs. If that's wrong, that's on them for claiming it. Subtract 28 lbs from that and you're at 147 lbs. That is very close to 150 lbs.

[0] https://evshop.eu/en/electric-motors/295-tesla-model-3-drive...

Exactly. I was very surprised to find out a fully loaded 40 ton electric truck only uses ~100kw / 100km ( https://www.youtube.com/@electrictrucker ) when my 2 ton Volvo averages 20-22kw/100km on road trips.