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[grmarks]

I wish I could find the pod cast video. The question of higher volts = less heat was asked by a pod cast listener during the question and answer segment.

I am paraphrasing his answer but a 70hp motor that runs on 100V has the same internal heat as a 70 hp motor that runs on 400V. The motor designs are different.
If you put 400V into a 100V motor I would expect (I am no expert) you will get less power and less heat assuming the total kw is the same i.e. more volts less amps. Less amps = less torque, but it should rev more.

[NEW2elec]

1. Podcast:  I looked for those a long time ago and the links I saved were dead but I think we watched the same Q&A session.  I read their body language as being caught going cheap and not "best" but I've never had my motor over heat so it has worked good enough for me.

2. Fins:  This new design just looks right.  They haven't shown the lower cross section of the bike yet and "may" have a small air scoop ramp setup to get more air flow over the motor but that just a guess on my part.  This new setup at least gives a uniform spacing for heat transfer and looks like more fins spaced closer together.  I think it was the 2011 MX maybe that had an airflow duct with like a vacuum hose blowing air over the old DC motor which they dropped for whatever reason.

3. Voltage:  Look myself and others are just guessing at this bikes operating voltage at this point.  It may be 116V or 232V or however they choose to set it up.  Zero has stated and it's pretty much a safety fact that 116V is nothing to play around with but most people can survive that shock.  I think Zero feels that the risk isn't worth it right now as that's what they have stated often in the past.  They are putting out a good bike with fun power and best range at that 116V rate and I feel they will likely keep it for now at least.

4. DC charging: I guess see point 3 since if the voltage stayed the same the stations weren't working with Zero's voltage (consistently).
I agree with Caza's quote: 
"Basically the biggest reason to have DC fast charging has more to do with being competitive with lightning and harley and less to do with an actual need and benefit.

I'll take faster level 2 charging any day over harleys solution of only level 3 and level 1."

For most of the USA there just isn't enough DC stations to work for our travels at this time and level 2 is in far more areas.  Europe is a different story they are way ahead of us in charging infrastructure of all types but DC for sure.  There is a great benefit to DC fast charging but it's just too scarce in 2019 in the US.

Anyway a few more weeks and all our questions will be answered and we can start talking about what we want next. 

[Richard230]

As far as Harley is concerned, I believe that the fast DC charging system has more to do with getting the Livewire customer back to the H-D dealership, than for reasons of product competition or customer convenience.  Remember, that every H-D dealership that sells the Livewire will have to have at least one DC charging station at their shop.  While the customer is charging up his bike, he can run into the accessory department and spend more money on farkles and H-D clothing - as well as being a target for salesmen to up-sell him on a new big twin "man's" bike. 

[NEW2elec]

Good point Richard.  Not having level2 charging is really unforgivable at that price.

[flattetyre]

Not having level 2 charging on any roadgoing motorcycle is really unforgivable at any price. USA 15 amp 120v supply should be a last resort for anything other than a electric bicycle or skateboard.

[domingo3]

As far as Harley is concerned, I believe that the fast DC charging system has more to do with getting the Livewire customer back to the H-D dealership, than for reasons of product competition or customer convenience.  Remember, that every H-D dealership that sells the Livewire will have to have at least one DC charging station at their shop.  While the customer is charging up his bike, he can run into the accessory department and spend more money on farkles and H-D clothing - as well as being a target for salesmen to up-sell him on a new big twin "man's" bike. 

I'd be interested to see how/if that works.  For myself in particular, I can't think of any realistic scenario where I'd head to a Zero dealer to plug in, no matter how fast it charged.  I mean maybe if there was a dealer that was exactly in the right place to enable me to make a trip I wouldn't otherwise have the range for, but generally I want to charge at my destination.  In other words, I might take advantage of charging if I was going to the dealer anyway, but I wouldn't go out of my way to stop by the dealer just for a charge. 

[Curt]

Idiocy

A good example were the 2012 motorcycles with the update to 75-7
The halved voltage (66Volt) was noticeable and could only be reduced with a perfectly adjusted motor. The same continuous power as the old motor he never had.The old motor, the heat could simply be dissipated by the forced ventilation!!!

Not sure what you mean with that anecdote. Are you saying lower voltage equates to lower heat?

When a Zero engineer makes a statement, don't take it out of context, call bullshit on what you imagine he meant, and start badmouthing.

The torque of a DC motor is directly proportional to the current in the windings. The heat dissipated in the windings is proportional to the square of the current in the windings. Heat is linked to the square of the torque.

None of this has to do with what voltage was used to make the electrons move at a particular rate. Interesting summary of RPM/torque/voltage/current motor math: https://qr.ae/TUr6Tu

Higher voltages don't increase torque but they do have other advantages, such as faster charging, and allowing for higher max RPM (back EMF is countered).

Heat increases resistance, and resistance increases heat. It is necessary to minimize resistance using larger wires/more wires in parallel, or better conductors or cooling. There are many variables to motor design but they can't violate physics.

Unless the SR/F has room temperature superconducting coils.

[centra12]

This is a quote from Zero's motor designer, He knows a lot more than me, and probably you.

My guess is with a higher voltage motor you use smaller wires in the windings because they carry less current but more windings give more power, but the smaller wires get hot with less current, the end result is the same heat.

Simply borrow a book with technical formulas from the library and read it.

Or read the technical data of a Brammo engine.

Nm/A

[Richard230]

As far as Harley is concerned, I believe that the fast DC charging system has more to do with getting the Livewire customer back to the H-D dealership, than for reasons of product competition or customer convenience.  Remember, that every H-D dealership that sells the Livewire will have to have at least one DC charging station at their shop.  While the customer is charging up his bike, he can run into the accessory department and spend more money on farkles and H-D clothing - as well as being a target for salesmen to up-sell him on a new big twin "man's" bike. 

I'd be interested to see how/if that works.  For myself in particular, I can't think of any realistic scenario where I'd head to a Zero dealer to plug in, no matter how fast it charged.  I mean maybe if there was a dealer that was exactly in the right place to enable me to make a trip I wouldn't otherwise have the range for, but generally I want to charge at my destination.  In other words, I might take advantage of charging if I was going to the dealer anyway, but I wouldn't go out of my way to stop by the dealer just for a charge.

But I bet most Harley dealers are usually doing stuff to bring their customers back into the shop, where they likely buy stuff.  My local H-D dealer is always having customer rides, events and other "life-style" functions that get the "faithful" together at the shop.  My BMW dealer does the same thing on a limited basis, but I think most Zero dealers do not - Hollywood Electrics being an obvious exception. 

[centra12]

Idiocy

A good example were the 2012 motorcycles with the update to 75-7
The halved voltage (66Volt) was noticeable and could only be reduced with a perfectly adjusted motor. The same continuous power as the old motor he never had.The old motor, the heat could simply be dissipated by the forced ventilation!!!

Not sure what you mean with that anecdote. Are you saying lower voltage equates to lower heat?

When a Zero engineer makes a statement, don't take it out of context, call bullshit on what you imagine he meant, and start badmouthing.

The torque of a DC motor is directly proportional to the current in the windings. The heat dissipated in the windings is proportional to the square of the current in the windings. Heat is linked to the square of the torque.

None of this has to do with what voltage was used to make the electrons move at a particular rate. Interesting summary of RPM/torque/voltage/current motor math: https://qr.ae/TUr6Tu

Higher voltages don't increase torque but they do have other advantages, such as faster charging, and allowing for higher max RPM (back EMF is countered).

Heat increases resistance, and resistance increases heat. It is necessary to minimize resistance using larger wires/more wires in parallel, or better conductors or cooling. There are many variables to motor design but they can't violate physics.

Unless the SR/F has room temperature superconducting coils.

An engine with power but without torque is worth nothing.
You have to understand the relationship between power and torque!!!

You're always talk about how good the Zero's performance is and that other bikes have problems keeping up.
Then simply deduce the torque to the minimum with your app and see what is left of the power !!! 
A heap of misery   

If their assertion were correct, the 2012 motorcycles with the 2013 engine would have to have the same continuous power as the 2013 motorcycles, but they didn't and that's not because of the smaller controller but because they overheated earlier 

[JaimeC]

Some idle speculation (because I'm bored):

The SR/F will not use a battery.  It will have the latest version of a "Mr. Fusion" power plant.  Zero's engineers have managed to miniaturize a flux capacitor to where it is practical to install in a motorcycle-sized vehicle.

When this baby hits 88 mph you're going to see some SERIOUS SHIT!!

[FuzzyTrace]

I'm calling a 180 rear, chain... and the reason shock was relocated was to either make room for reduction gear assembly or to offset weight of a single sided swingarm

[togo]

I wish I could find the pod cast video. The question of higher volts = less heat was asked by a pod cast listener during the question and answer segment.

I am paraphrasing his answer but a 70hp motor that runs on 100V has the same internal heat as a 70 hp motor that runs on 400V. The motor designs are different.
If you put 400V into a 100V motor I would expect (I am no expert) you will get less power and less heat assuming the total kw is the same i.e. more volts less amps. Less amps = less torque, but it should rev more.

Was it this one?  Luke Workman's interview at motorcycle.com


I know the point has been made that the high-efficiency power-FET transistors in the controllers tolerate 116VDC, but that for the automotive controllers, you need IGBTs, which have a little less efficiency in the controller.  But automotive power cables are longer, so they have more loss in cable length at the lower voltage.

[dpmcdonald]

I'm calling a 180 rear, chain... and the reason shock was relocated was to either make room for reduction gear assembly or to offset weight of a single sided swingarm

Oohh, single-sided swing arm would be sweeeeet..

[NEW2elec]

Nah Togo, that is a good interview and video but the podcasts were on a streaming service and it was a few Zero execs and a guy reading questions off a laptop.  I think you could rewatch it for like a day then they just were dead links.