Zero Motorcycles

[ylexot]

BTW, for anyone interested, I found this book:
Amazon.com: Build Your Own Electric Motorcycle (Tab Green Guru Guides) (9780071622936): Carl Vogel: Books

I haven't bought it yet, but I have a few build-your-own-electric-car books and their major failing is that their calculations for motor power/battery capacity/range/speed/etc are difficult to extrapolate for motorcycles because they are well outside the bounds of what the books discuss. That book should be a little better for figuring that stuff out.

 

[Lugnut]

There was an electri drag bike at MIR last year. It ran on a LOT of D cell lithium ion batteries and was pretty fast as I recall. The driver said every now and then a cell would explode when he was headed down the track

 

[aps45819]

I haven't bought it yet, but I have a few build-your-own-electric-car books and their major failing is that their calculations for motor power/battery capacity/range/speed/etc are difficult to extrapolate for motorcycles because they are well outside the bounds of what the books discuss. That book should be a little better for figuring that stuff out.

One thing I don't understand is why the electric bikes (at least the ones that raced at Isle of Man) don't use transmissions. Seems like a 2 or 3 speed gearbox would do a lot to reduce battery consumption.

 

[Larry Gude]

One thing I don't understand is why the electric bikes (at least the ones that raced at Isle of Man) don't use transmissions. Seems like a 2 or 3 speed gearbox would do a lot to reduce battery consumption.

Can't help with the details of the engineering but, electric cars, eventually, as I understand it, will not have tranny's either. Something to do with the fact that the torque is there down low in an electric motor and it can also give you the high end simply because of the way an electric motor is designed and works where as an internal combustion must have a tranny to work the way we want in a car/truck/bike.

Supposedly, electric motors are FAR superior for a car. We're just not set up to use them. Yet.

 

[Lugnut]

One thing I don't understand is why the electric bikes (at least the ones that raced at Isle of Man) don't use transmissions. Seems like a 2 or 3 speed gearbox would do a lot to reduce battery consumption.

From what (little) I understand, most electric vehicle motors are shunt wound. They respond to increased loads with increased torque. If you choose a motor with enough torque for the job you just dont "need" a transmission and the parasitic losses that come with it.

Yle, do I have that right?

 

[GWguy]

Can't help with the details of the engineering but, electric cars, eventually, as I understand it, will not have tranny's either. Something to do with the fact that the torque is there down low in an electric motor and it can also give you the high end simply because of the way an electric motor is designed and works where as an internal combustion must have a tranny to work the way we want in a car/truck/bike.

Supposedly, electric motors are FAR superior for a car. We're just not set up to use them. Yet.

From what (little) I understand, most electric vehicle motors are shunt wound. They respond to increased loads with increased torque. If you choose a motor with enough torque for the job you just dont "need" a transmission and the parasitic losses that come with it.

Yle, do I have that right?

Yup and Yup. The low-end torque on an electric motor is powerful enough to negate the use of a tranny. Ever listen to the Metro as it speeds up? No shift changes.

 

[glhs837]

The problem is economical energy storage, Larry. Get that right, and yep, electric motors are great. Problem is cheaply storing enough energy in a compact form. Look at ranges and recharge times for what we have now, and for equal or less money, I can put twice the range into a vehicle in about 1/100th of the time.


Let me pack 300 miles of electrical charge into a box that weighs the same a full gas tank (20 gallons x 6lbs = 120lbs) in under 5 minutes, for under $50, and folks will jump all over it.

But now, it takes me hours to fill a box that weighs twice that with maybe 200 miles, if I drive like I have Miss Daisy in back. Folks just wont accept that.

 

[ylexot]

Can't help with the details of the engineering but, electric cars, eventually, as I understand it, will not have tranny's either. Something to do with the fact that the torque is there down low in an electric motor and it can also give you the high end simply because of the way an electric motor is designed and works where as an internal combustion must have a tranny to work the way we want in a car/truck/bike.

Supposedly, electric motors are FAR superior for a car. We're just not set up to use them. Yet.

Yeah, electric motors have max torque at zero rpm and the torque curve is pretty much flat (I think). Plus, they are usually capable of much higher rpms than gas motors. They might benefit from a simple transmission, but they don't need one and the transmission adds weight and friction losses.

BTW, one thing that I saw you can do with electric is to run two motors and switch between powering them in parallel or in series depending on speed/power needs. Of course, that requires a special controller that is $$$$.

 

[Lugnut]

This is the current state of the art in production elecric cars. Vera niiiiice... But expensive


Tesla Motors - High performance electric vehicles. Available now.

 

[Larry Gude]

The problem is economical energy storage, Larry. Get that right, and yep, electric motors are great. Problem is cheaply storing enough energy in a compact form. Look at ranges and recharge times for what we have now, and for equal or less money, I can put twice the range into a vehicle in about 1/100th of the time.


Let me pack 300 miles of electrical charge into a box that weighs the same a full gas tank (20 gallons x 6lbs = 120lbs) in under 5 minutes, for under $50, and folks will jump all over it.

But now, it takes me hours to fill a box that weighs twice that with maybe 200 miles, if I drive like I have Miss Daisy in back. Folks just wont accept that.

I accept that! A gallon of oil is a hell of a lot of energy.

 

[GWguy]

BTW, one thing that I saw you can do with electric is to run two motors and switch between powering them in parallel or in series depending on speed/power needs. Of course, that requires a special controller that is $$$$.

I had designed one like that using 3 smaller motors, power output in parallel, but cascaded input. The more torque, the more demand, the higher the current, which added motors to meet demand. When demand was met, power was reduced to the unnecessary motors which could also act as chargers while not powering.

Yeah, never got past the controller, never got to a working model.

 

[ylexot]

The problem is economical energy storage, Larry. Get that right, and yep, electric motors are great. Problem is cheaply storing enough energy in a compact form. Look at ranges and recharge times for what we have now, and for equal or less money, I can put twice the range into a vehicle in about 1/100th of the time.


Let me pack 300 miles of electrical charge into a box that weighs the same a full gas tank (20 gallons x 6lbs = 120lbs) in under 5 minutes, for under $50, and folks will jump all over it.

But now, it takes me hours to fill a box that weighs twice that with maybe 200 miles, if I drive like I have Miss Daisy in back. Folks just wont accept that.

Yeah, that's why electric cars are not able to replace gas cars, but they are good for commuting (which is where most miles are driven by the average person).

That is also why a hydrogen fuel cell is an attractive solution...it would essentially be a refillable battery.

 

[ylexot]

I had designed one like that using 3 smaller motors, power output in parallel, but cascaded input. The more torque, the more demand, the higher the current, which added motors to meet demand. When demand was met, power was reduced to the unnecessary motors which could also act as chargers while not powering.

Yeah, never got past the controller, never got to a working model.

I was looking to get a Zilla controller since they can be programmed for serial/parallel, but they are ~$2k!

 

[Lugnut]

A lot of the range improvements in recent years has come from regenerative braking. Hit the brakes and the controller swaps current paths and Voila! The drive motor is now a generator and the the batteries are the load, slowing the car while providing a brief boost to battery charge.

 

[ylexot]

A lot of the range improvements in recent years has come from regenerative braking. Hit the brakes and the controller swaps current paths and Voila! The drive motor is now a generator and the the batteries are the load, slowing the car while providing a brief boost to battery charge.

That also requires a special controller and I don't think it can be done with the common, inexpensive, shunt-wound motors.

 

[glhs837]

Living with the Tesla Roadster Sport: One week in an electric light orchestra — Autoblog

Just to show the issues with range. And this is in a superlight chassis with virtually no cargo capacity. Time for a full recharge on 110v is about 40 hours. On 220v, thats only a six hour refill. So, I can drive to Baltimore and back, but then I cant go anywhere for six hours.

Scale this up, and you see the issue. To move a 3300 or say a 4200lb package 250 miles, and supply power for headlights and heaters, even with getting some back from braking, you would easily need twice the Teslas power storage capacity, which cuts your cargo capacity, and would take even longer to charge.

What you really need, barring some breakthrough in storage, some super-duper capcitor, is a way to make electricity onboard that doesnt require oil. Say a real Mr Fusion.

 

[ylexot]

What you really need, barring some breakthrough in storage, some super-duper capcitor, is a way to make electricity onboard that doesnt require oil. Say a real Mr Fusion.

Hydrogen fuel cell. :shrug:


Or you need to go the other direction...a super light vehicle that doesn't have all of those power accessories...like an electric motorcycle

 

[glhs837]

Hydrogen fuel cell. :shrug:


Or you need to go the other direction...a super light vehicle that doesn't have all of those power accessories...like an electric motorcycle

But the hydrogen cells have issues of their own, maybe worse than a battery. You need a few things to be solved.

1. The require a goodly amount of platinum, not an inexpensive metal.
2. Like batteries, they have problems with high and low temps
3. They require either very pure ($$$) hydrogen, or a reformer to turn other fuels into hydrogen, that adds heat and weight.

Believe me, I know IC engines days are numbered, but we are not there yet.

 

[aps45819]

Let me pack 300 miles of electrical charge into a box that weighs the same a full gas tank (20 gallons x 6lbs = 120lbs) in under 5 minutes, for under $50, and folks will jump all over it.

But now, it takes me hours to fill a box that weighs twice that with maybe 200 miles,

I don't see the recharge time as a big problem IF you can recharge at home. I don't think most folks don't drive over 100 miles a day. Average workday for me is about 25 miles if I run errands
How many hours a day is your car/bike sitting parked at either work or at home? Maybe extension cords at work could become employee perks

 

[aps45819]

I filled out the form on their website, if Zero wants to come up (they have an address in Chesapeake, VA) and set up some Demo rides, I'll post the time and location