Instructables

Gomi Style - Electric Motorcycle Conversion

video Gomi Style - Electric Motorcycle Conversion
As seen in MAKE magazine! We started with a Honda Rebel junker and a dream - to make a practical, zero emissions vehicle for commuting in San Francisco. Armed with a basic metal shop, we methodically convert the Honda rebel 250 into a clean quiet bike in about a week.
frollard6 years ago
I promise I'm not trolling - great build, and I want to build one myself;

Alas the use of the term 'zero emission' bugs me. Power isnt free; it comes from power plants. You can argue you use solar (what third world country got crapped on to make the silicon pv cells?), or hydro (hydro has no emissions, but usually destroys thousands or millions of hectares of land in resivoirs)...but sadly a huge percentage, and I insist on HUGE percentage of all worldwide power is still dirty - carbon emission based generation. Couple the inefficiency of the batteries, with the wall charger, with the power transmission, with the generation inefficiency, and a gasoline engine is *practically* on par for energy efficiency/carbon emission.
I recently helped a guy build a small water turbine that worked off a long length of pipe that provided the head from a small stream, taking only a small amount of water from the stream and returning it back. this would easily recharge the bike


Does somebody have any plans for the bike project as there is no point in reinventing the wheel
sir i m having an idea to charge the batteries by running a gas turbine using the combustion products energy .
and i m thinking of furnishing of the bike which works on petrol and electricity.
so please give me a mail on
dahiyaashish44@gmail
It's instructables - there are hundreds of bike projects.
sparkyrust (author)  frollard6 years ago
Hi- Thanks for the comments. I appreciate this debate. It comes up a lot. Zero Emissions is a term specific to vehicle tailpipe output, not the entire range of energy production. While you make some very good points, the term has it's defined meaning. Where I live, the AC power comes from a significant percentage of renewable sources. But even where it it dirty, the per-mile comparison of the amount of pollution from a "grid" source vs the amount of pollution from the burning of gasoline in a motorbike is not even a close comparison. The internal combustion is far less efficient and far more dirty. Power from the grid costs literally pennies per mile, and the grid sits mostly unused all night long - just waiting for the millions of electrics and plug-in hybrids that will soon be widely available.
I like your bike, it is very cool and well done. But if you consider ground level ozone a pollutant, and the EPA and my lungs do, then electric vehicles will never be zero emission. And the cradle to grave impact of batteries is a huge elephant in the room that no greeny ever willingly addresses. A turbo-diesel ICE properly designed combined with hydraulic regeneration is in my view by far the most efficient design when the real big picture is examined. Not just the 'tailpipe'. That "tailpipe emissions" thing is a canard for certain. Folks like to talk about "big oil" but they need to look in the mirror and start following the money trail of "big electric" that those Al Gores and such have extremely heavily invested in battery technology, carbon credit exchanges, Solyndra, money-sucking-bird-harvesting wind farms etc. People are people. Some don't hide their true motivations, others wrap themselves up in Earth Day flags and pretend their crap doesn't stink. Meet the new boss, same as the old boss.
I'm intrigued to know where you live then. I don't know how it works else where, but in the UK all power is fed into the grid and everyone draws from the same grid. No one gets to say "oh I only want electrons from solar or tidal, those nasty coal ones just wont do". Perhaps you're offgrid, in which case I've got it all wrong. Unfortunately I think you're right about the definition of Zero Emissions but surely this term must have been invented by someone with something to sell. Like these hydrogen cars, what a load of rubbish, the factories making the hydrogen are doing more damage than a car would in its life. Don't get me wrong I'm all up for petrol free transport, I'm just not sure we've found a better (greener) alternative yet. Decomissioning lead acid batteries isn't exactly green. Also if everyone does suddenly decide to use hybrids and electric that charge at night then night time electricity won't remain cheap, nor will there be capacity in the grid for it. We would need many new nuclear plants to cover this (in England at least).
sparkyrust (author)  lasersage6 years ago
PGE is my local power utility. It's not perfect, but it is one of the best in the US.
http://www.pge.com/about/environment/pge/cleanenergy/index.shtml
Also, we recycle over 90 % of Lead Acid batteries here as well. As for grid capacity, the US grid could handle a switch to plug-in tech for 180 million cars right now. http://www.treehugger.com/files/2006/12/180_million_plu.php We have a lot of issues to deal with here in the US, but supporting cleaner AC vehicles seems to be coming around a bit.
Some places in the world now allow free choice of which 'company' you buy from. some companies offer part or all 'green' power, usually at a premium. Also some areas allow net-metering, where if you can generate some of your own, you can get paid to put power back in the grid.
I can agree with that :) As per the grid going unused - thats a good thing :) less draw on the power plant means less fuel in, and less carbon out (generally). Thats like saying since the alternator in the car is spinning you might as well draw power from it. Newton explained that one best. I would still like to see stats of estimated powerplant-to-rubber on the road efficiency. Also, gasoline only costs pennies per mile before taxes - if household electricity were taxed like gas it would be astronomical. We know empirically that 15-25% of the energy in gasoline can be extracted to motion, but gasoline has potential for nasty output chemicals where most power plants clean those out.
sign up for a renewable energy contract. don't you have that where you live?
I live in oil country - alberta Canada - its a HUGE resource out here, and 'nothing' is gonna stand in 'dem boys ways'. It's all legislated bs. We dont even have net power metering for home generation. Blargh.
I don't know where you are getting your figures, but with an electric motor/battery combo being over 70% efficient and a ICE vehicle being something less than 20% (optimally) it is not even close. Even the powerplant emissions are a canard because they are closely monitored on a daily basis, and plants are far more efficient in their use of fuel because they run at a constant optimum speed and do not have to be mobile. On the other hand there are a dozen ways that a car can be less efficient and clean than it should be ranging from incorrect air pressure in the tires to accelerating too aggressively at stoplights. Also if you are charging your vehicle at night it actually is making use of underused capacity in the power plant.
kpolydwrou3 years ago
Nice video and nice work done!
Could you give the specs of the components used? Like what kind of controller or motor (brushed,brushless ,watt?,voltage?) and how much the whole project costed?
Kind regards
randomray6 years ago
Ack! Where to start ? Really ,it costs far less to charge an electric , pennies actually .Gas costs far more then the pennies you think. Granted there is a lot of tax on petro , a lot more in england then this side of the pond .Power plants can't just shut down at night they can cut back some but there is no big switch they can just flip to the off position .So there really is a night time surplus of power .In the states the grid covers all of the states and "Canada?" but there is a power drop over over distance .
ac-dc randomray4 years ago
You can't really make a fair comparison based on fuel cost.  The money spent on the conversion could have been sitting in a bank drawing interest.

  The batteries need to be periodically replaced or else you find your travel distance becoming too short to be reasonable and you certainly don't want to be stuck somewhere not able to recharge it while it is far easier to walk to a gas station and buy a can and gas.

Point is, you'd have to travel a lot to make up for the beginning disparity in parts costs and if you travel a lot it makes the shorter range of an electric setup (especially between recharge opportunities as I began to mention above) less and less desirable.

I don't mean to suggest it is a "bad" idea per se to have an electric bike, only that fuel cost for a motorcycle is one of the least important issues in ownership and use.


I can't wait till prices come down, because sadly EV conversions are not for low to mid income city apartment dwellers-which are the type of people who would most benefit from these. At $800 for a decent pancake motor, $400 or so for a decent 2 or 3KW controller, another few hundred in batteries, plus custom welding, it's an expensive proposition. I'm trying to get a neighbor who has a RS50 that's been sitting for three years unridden to sell it at a reasonable price. Biggest problem with me doing an EV conversion? There's no electrical outlet in the parking areas so I can't charge overnight.
You can make a decent electric bike for about $300-$500, and it would go as fast as you would want to go in a city environment (25-30mph). Making an eBike is a good way to get your toes wet because the parts are cheaper and you can do it with little or no welding. Even easier than that would be to get an electric scooter and beef it up with more batteries or a better motor.
I recently sold my electric scooter because it's way more expensive than a petrol-powered scooter.  The problem is that the batteries only last 3 years and they cost a fortune (in scooter dollars).  Now having tried both, p-p scooters are much cheaper to operate.  So it's back to petrol for this eco-rider.
bornon5115 years ago
have you guys thought about doing a hybrid with an alternator and an engine from a lawnmower?
mnbouchet5 years ago
what kind of motor should I use if I want to build something like this, I have been looking, but can't seem to find something that suits my needs. thanks.
agis686 years ago
At least i know from how to start.....I have a REBEL motorcycle the famous CN500 by Honda builded year 1980!. It works fine . It has 120K miles in its counter and still runs. Of course it cost me a lot in gasoline.... The project was nice but u need a team and a junkyard to do this
arni02026 years ago
I wish I knew how to cut and weld metal... I would totally rock this project. but I'd lose a finger or 3. oh and burn my house down lol
Every farmer knows how to weld. Ask one to teach you. -Every community collage has welding classes that are cheap - - you need the lessons not a degree. There also Online tuts - - this is a skill that anyone can learn. Check out the battery welder instructables. P.S. You weld outside. No Fires ;o)
How far can a bike like this run? How long does it take to recharge?