In the list of "odd things nobody ever tells you about....."
I found a few quirks while working on this project.
Rear Brake Spring Bracket
When I was getting the cycle all back together and testing to make sure everything was working right, I had to hook the rear brake back up. On a motorcycle, the rear brake is activated by a right-foot pedal. A spring pulls that pedal back up when you release it. But here's the weird part.... I couldn't figure out where that spring connected to on the frame of the motorcycle. I consulted the repair manual, and found out that the spring hooks on THE MUFFLER!
By converting my motorcycle to electric, I no longer had a place to connect my return spring! So, I built a little tiny, custom bracket, just for the spring to go to. On your project, you might come across some other odd quirk like this. It's not a big deal, it just gives you the opportunity to be creative and come up with your own solution!
The Gas Tank
Some of the most common questions I get about an electric motorcycle are about the gas tank. Typical is "If it doesn't have any gasoline, why do you have the gas tank?" and "Why don't you just STUFF that gas tank full of batteries!?"
The short answers are that motocycles just don't look like motorcycles without the gas tank, and you really can't fit batteries in there anyways.
When I got the motorcycle, the tank was already rusted and dented. It was completely bone dry, but I still left it open for a few days before cutting off the bottom with an angle grinder, so I could beat out the dents from the inside. Then I stripped the existing paint, and gave it a new paint-job. The top part of the motorcycle frame is a tube that goes straight through the gas tank. The tank is almost like a saddle-bag that hangs over that bar. The tank is also curved and batteries are nearly always big rectangular things. So, between the frame and shape of the tank, you just AREN'T going to cram batteries in there (That would also raise the center of gravity on the cycle as well.) The tank does make an excellent cover for over the batteries. It would also be a good place to mount the motor controller or a battery charger, as long as you make sure they have enough ventilation.
Some electric vehicle enthusiasts will even make a FAKE gas tank from foam, fiberglass, or plastic. It gives the cycle that cool look, but since it's custom, can be designed to accomodate batteries or other components. Remember, on some cycles today, the "gas tank" really isn't. On Goldwings, the "tank" is just a filler port, but the actual fuel tank is elsewhere on the vehicle. The "tank" makes a nice box for gloves, goggles, and maps.
LOUD PIPES SAVE LIVES
One myth of an electric motorcycle is that it's silent. It isn't - it makes some noise, but it is SIGNIFICANTLY quieter than a gas motorcycle, especially one with modified tailpipes. Should the need arise for my cycle to be loud, I have a horn and am not afraid to use it.
Even though most car drivers today have their windows rolled up, with the air-conditioning cranked, and the radio blaring, (so they can't hear a thing anyways) some people still think that a motorcycle being obnoxiously loud is a safety feature. After the millionth time that I heard that "loud pipes save lives" (mostly from NON-motorcyclists), I wondered if there was a way I could play with that in a way that an electric motorcycle could be BETTER than a gas one when it came to making noise.
I connected an MP3 player to my computer and downloaded some various motorcycle sound effects. I then attached self-powered computer speakers inside the hollowed gas tank and bungie-corded the MP3 player to the handlebars. I could now sound like a Harley, a Kawasaki, a 50cc scooter, or the George Jetson flying car!
See details on that here on Instructables.
If you haven't already, take a riders safety class. Motorcycle riding is a skill. It should be learned and practiced. Make sure to always "get the hang of it" again in the spring after pulling the cycle back out of winter storage. Come to think of it winterizing should be covered here as well.
When I looked through the cycle manual on winter storage, I was surprised at how much work it was to store a gas cycle for the winter! You have to change the oil, run the tank dry, and doing a surprisingly-long list of other things! When back out of storage in the spring, you are supposed to change the oil (again!) and have another laundry list.
On my electric motorcycle, here's how I put it away for the winter.
- Charge the batteries
- Pull out the battery disconnect
- Ignore the cycle for the rest of the winter (I just keep mine in the back corner of the garage.)
In the spring, it's
- Charge the batteries (they will self-discharge a bit over the winter)
- Check the air in the tires.
- Put in the battery disconnect, turn the key, and ride the cycle!
A vehicle becomes more efficient the lighter and more aerodynamic it is. You can also help make it more efficient by reducing electrical loads. For example LED lights consume less power than incandescent ones. On my cycle, I replaced the stock taillight with an LED light from the autoparts store. They are mass-manufactured, DOT-approved, and affordable.
I'd like to have a low power-draw headlight, but at this time there are only a few DOT-approved LED headlights available on the market, and they are rather expensive. I'd like to get one when the price comes down, or possibly build my own.
The turn signals on the cycle are still incandescent, as they use nearly no power at all (how often are turn signals on!?) It didn't make sense for me to spend the money to upgrade them to LED. If I were building a new, custom motorcycle, I would install LED lights all the way around right from the start.300 Miles per Gallon!
Another really cool thing about electric motorcycles is how crazy efficient they can be! After my first ride on a fully charged battery, I recharged the battery, tracking how much energy was used (with a Kill-a-Watt energy monitor
) and divided it by how many miles I traveled (using the trip odometer.) I used electric-to-gasoline-conversion numbers from MIT
to calculate what the equivalent "miles per gallon" would be. It came out to over 300 mpg!
Is it fair to use MPG when talking about electric vehicles? No, not really. Gasoline can't be made from wind turbines or photovoltaic panels, and there aren't nearly as many gas stations as there are electric outlets. When talking about electric vehicles, we might use "MPGe" or miles per gallon equivalent. It's not a perfect analog between gas and electric, but it gives people who have lived in a world of miles per gallon a better sense of the efficiency of an electric vehicle. Keep in mind that heat, noise, and vibration are all signs of POOR efficiency. An electric motorcycle doesn't have a hot engine, with noisy exhaust that needs mufflers, and it doesn't shake from engine vibration.Regenerative Braking
Many people are now familiar with the concept of regenerative braking, due to the mainstream popularity of hybrid cars. So, of course they ask if my cycle has it as a feature. No it doesn't. Although a DC permanent magnet motor can make a fine generator, adding regenerative braking adds to cost and complexity of the project. Also, most braking is done on the FRONT of a vehicle. On the cycle, the motor is connected to the back wheel, where it would be less effective for regen. Also, overbraking on the rear of a cycle can lead to a uncontrolled skid. Many "hypermilers" get better fuel economy by avoiding braking in the first place, using simple eco-driving techniques, such as "timing lights".Budget
We wouldn't want to finish talking about this project without mentioning what it cost to build. First, let me start off by saying that any project like this can have WIDE VARIATION in the cost of the components and the final budget. On my project, some of the parts, like the ammeter, power indicator light, and battery charger were items that I already had or were salvaged materials.
Here's a basic run-down of the project budget.
- Donor bike - $62 (bought it for $100, sold scrap parts for $38)
- Motor - $500
- Motor controller - $300
- Twist Throttle - $50
- Batteries - $700
- Drive Sprocket - $20
- Chain - $10
- Custom Rear Sprocket - $100
- Fuse, holder, battery cut-off, and cabling - about $100
- Repair Manual - $20
- Main contactor - $50ish
Add it all up, and the project came out to right around $2000. If a person already had some other parts, tried used batteries, or installed an inexpensive forklift motor, the price could come down. (See Russ' cycle photo in the last step! He built his for nearly nothing!)
On the other hand, if it was all brand-new parts, with a high-end motor and controller, and lithium batteries, the project could easily be $10,000. (Check out Tony's cycle in the last step!)
On the electric car project, I was a bit smarter about money, creatively used salvaged parts, and built an entire electric car
for about $1300 total.Cost of charging
Electric motorcycles are efficient and have smaller battery packs than electric cars. My cycle usually costs about a penny a mile to charge. That will vary a little bit depending on what electric rates in your area are. Electric rates are much less volatile than gasoline prices.
If you have solar, you can charge your cycle for "free"!
In some areas, a "Time of Day" plan is available. You pay double the price of electricity during "peak load" times and you pay HALF the price during "off-peak" times, usually at night. Check with your local power company. By recharging your vehicle only at night, you can cut your electric "fuel" costs in half! Simplicity
Lastly, I'd like to mention that even though I went into a lot of detail on this project, Electric Motorcycles are SIMPLE. They really are just about cleanest, most straight-forward transportation possible. Knowing what I know now, I could build an electric motorcycle in a three-day weekend.
I know one guy who I mailed a photo of my motorcycle to. When I saw him the next week, he had already built an electric motorcycle almost exactly like mine!