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[DonTom]

I wish somebody can do this for Zeros. This is for my Tesla:




-Don-  Auburn, CA

[Richard230]

I bet Zero could publish a chart like that - if they wanted to. 

[NEW2elec]

No need to make a new chart just make the Zeros have the same specs as the Teslas.   

[DonTom]

I bet Zero could publish a chart like that - if they wanted to. 

I think we would find the best range on a Zero at around 20 MPH, unlike the 40 MPH on my Tesla.

Perhaps use the same chart and  divide by 2 . . . . 

-Don-  Auburn, CA

[DonTom]

No need to make a new chart just make the Zeros have the same specs as the Teslas.   

Simple. Just put a 75 KWH battery in our Zeros (as my Tesla has) and then our Zeros  will even beat the Tesla spec!   


-Don-

[Richard230]

No need to make a new chart just make the Zeros have the same specs as the Teslas.   

Simple. Just put a 75 KWH battery in our Zeros (as my Tesla has) and then our Zeros  will even beat the Tesla spec!   


-Don-

And may end up weighing almost as much.   

[BrianTRice@gmail.com]

Drag on a Zero is much more complicated and even rider dependent. DoctorBass and I at least have spreadsheets that calculate this, and I’ve been working on a web application for the more general case, but haven’t polished it for publication.

[Bill822]

I wish somebody can do this for Zeros. This is for my Tesla:

-Don-  Auburn, CA

They do. Zero posts range guides for each of their current bikes on the website. Just click "Full Specs" for this list. "City" is stop and go 35mph. They also show 55 & 70 MPH. Enough info to plot your own chart.

[valnar]

I was just looking for a chart like that.  I was also trying to look up wind resistance and drag on us humans riding around like a sail on any motorcycle.  I'm sure there is a point somewhere around 20mph (pure guess) where it becomes a factor.

[DonTom]

They do. Zero posts range guides for each of their current bikes on the website. Just click "Full Specs" for this list. "City" is stop and go 35mph. They also show 55 & 70 MPH. Enough info to plot your own chart.

My Tesla has a range of 370 miles at 20 MPH. What do our Zero's do for total range at 20 MPH?

At 80 MPH, my Tesla has a range of 270 Miles. How about our Zero's ?

-Don-  Auburn, CA

[Bill822]

I was just looking for a chart like that.  I was also trying to look up wind resistance and drag on us humans riding around like a sail on any motorcycle.  I'm sure there is a point somewhere around 20mph (pure guess) where it becomes a factor.

Wind resistance increases with the square of the velocity. So if it takes 4 pounds of force to push you and the bike through the air at 20MPH it will take 16 pounds of force to overcome the wind at 40MPH, 256 pounds force at 80MPH. You can see that riding into a strong headwind can kill your range while a tailwind feels like an extra battery.

The measurement of how much resistance a bike and rider present to the air is represented by the drag coefficient times the frontal area presented to the wind (CdA). There is a table here for some sporty ICE bikes: http://elmoto.net/showthread.php?t=3400 Note the separate numbers for prone and crouched. This refers to the rider's position, upright or lying on the tank. Sitting upright on my Triumph Speed Triple I have a CdA of 0.492. A Tesla Model 3 has a CdA of 0.23. Even though bigger the car takes only half the force needed to move my bike through the wind at the same speed. This is why fast racebikes always have elaborate fairings and aerodynamic riders tucked in low.

You can experiment using the power consumption readout on your screen (Zeros have that, right?). You will find that keeping your body position low and aerodynamic will noticeably reduce the power needed to maintain speed. Some people add windshields or even fairings to their bikes to smooth airflow and get longer range. Bicycle racers take this stuff very seriously and they have some good info (including the math) here: https://www.cyclingpowerlab.com/CyclingAerodynamics.aspx

I hope this reply wasn't too long. I do tend to go on...

[valnar]

That's all good info Bill.  Unfortunately it's hard to clarify the science into exact numbers, and it's possible the raw power of our bikes can overcome some of the lighter wind resistance.  There are also efficiencies at stake which are hard to clarify.  ie. Do you really gain maximum range going 2 mph?  We have to take in the reality of the bike and battery itself into the science.  There is where a realistic curve like the one presented by Tesla works well since it adds other factors besides wind resistance.  And yep, I realize the rider's profile and weight are one of those factors.

I suppose there is one way to find out!  Calculate your constant speed and distance until the battery dies a dozen times on a straight level road.  lol

[NEW2elec]

DonTom, Electric Terry had a FB post where he Hyper Miled for some crazy range.  I want to say >200 miles but he was crawling near the coast.

Bill822, thanks for the post.  Somewhere in all my Bicycling magazines or in one of my training books was that formula with all the factors for speed and energy use while riding.  The degree of elevation increase or decrease, the air density relative to sea level, humidity, rolling resistance, wind speed for sure.  Spend $2000 for lighter wheels to reduce your rolling rotational weight and not $400 for carbon fiber handle bars as fixed weight.
The big part to remember was the square of the velocity which is what kills our highway range.
On the bicycle it meant I had to just keep carb loading.    Unfortunately I still carb load but don't ride so I'm carrying around an extra 60lbs.  All well time is undefeated.
It hurts the gas mileage on an ICE bike as well but the super energy density of gas help cover that up (and gearing).

[BrianTRice@gmail.com]

That curve is much more specific than Zero’s (or other OEM’s) accurate estimates or the rough guide that drag is proportional to the square of speed.

I will reiterate that drag on an electric motorcycle depends on airspeed, not groundspeed, and is much more complicated and variable per rider than a Tesla. There is a cubic factor in addition to the square factor for drag, when irregular shapes that induce turbulent flow are a factor like on motorcycles.

There is also rolling resistance (linear) and that varies by tire patch size and the powertrain losses.

This is one reason I started developing an interactive worksheet web application. Maybe I’ll finish it, but I’m still behind on other projects.

[Bill822]

...  I was also trying to look up wind resistance and drag on us humans riding around like a sail on any motorcycle.  ...

^That is what I was replying to.
If you are interested I can tell you how to test for your optimum speed w/o using the whole battery. Just like the Tesla or any road vehicle your energy usage will vary depending on amount of acceleration, whether there are hills, and the weather. In normal riding wind resistance is the main load the motor must overcome.

EDIT: Just saw Brians post. Good stuff. Motorcycles are a complex aerodynamic problem. Few will bother to really optimize their bike and riding. As a recovering hypermiler I was hoping to avoid that rabbit hole once my SR/F arrives but I will no doubt play around a little and see what happens.