<$1k DIY Neighborhood Electric Motorcycle

[Christ]

A while back, I was cutting up some wood, and I'm not used to a manually oiled chainsaw, so I forgot to push the handle to oil the bar... it completely locked up. Motor still ran, but it would NOT lock up the clutch to pull the chain around until I oiled it up a couple times.

Needles to say, it scared the sh!t out of me, because it's not my saw... I was borrowing it from a friend, who's had it for literally about 15 years.

[MetroMPG]

Cool! A video! I like the sound - alien space vehicular.

[captainslug]

The wiring bucket is getting a bit cramped. Good thing everything is labeled.
I've added a relay to the charger connector so that the charger is disconnected from the batteries once the ignition is switched on.

This prevents the charger from drawing power from the batteries, and it prevents it from getting confused about the charge state once the charger cord is plugged into a 110VAC outlet.
The charger isn't very sophisticated and isn't meant to be onboard, so I have to fool it into thinking I'm plugging and unplugging it.

I used a leftover brake lever and a toggle switch which I made a mounting bracket for. This lever will control the relays to switch the motors from parallel wiring to series.

And here are the relays and the resulting hairball of wires

The battery rack mounting holes have been moved so that there's enough space to install a larger front sprocket.

Left to do
1. Drill/cut new front sprocket
2. Finish reassembly
3. Testing
4. Adapt and install retractable cord reel in the empty slot of the battery rack

[captainslug]

Vinyl dyed it black, then changed out the connectors on the retractable cord reel.

Drilled and cut a 40-tooth front sprocket.

Installed the cord reel in the now empty slot in the battery rack.

And after a great deal of annoyance trying to fix the cut-off relay for the charger, it's working.

The bike can now be charged from the built-in extension cord or the gas tank plug receptacle.

I'm just waiting for my replacement drive chain to come in the mail.
The series-parallel switching relays are working as expected.

[captainslug]

I give up.
The Series-Parallel switching works, but the series mode doesn't offer enough torque to be very useful for acceleration.
Top speed in Parallel is only 18mph.
Top speed in Parallel is 35mph.
And the battery pack is struggling to supply the demanded power.

The bike is too heavy. The motors are too small in wattage for the weight. The batteries don't have enough capacity.
Most of the above issues could be resolved with a larger pack of lithium batteries, but I'm not wiling to spend that kind of money right now.
And I can't afford to work on this project any further for the time being.

http://www.youtube.com/watch?v=XrN3vfft_bs

[Christ]

Originally Posted by captainslug

I give up.
The Series-Parallel switching works, but the series mode doesn't offer enough torque to be very useful for acceleration.
Top speed in Parallel is only 18mph.
Top speed in Parallel is 35mph.
And the battery pack is struggling to supply the demanded power.

The bike is too heavy. The motors are too small in wattage. The batteries don't have enough capacity.
And I can't afford to work on this project any further.

O RLY??

Dude, don't get discouraged, you'll find a way to make it better/lighter/faster.

You've spent alot of time and money on this project, too much to see it just get closeted and never spoken of again - Even if you can't work on it right now, you'll still be able to find better resources at some point, and until then, you can use what you have (gently, of course).

Maybe with the money you save in fuel, you can start looking into a NiCd battery pack, or something even lighter/better! Even if you can't use it to commute every day, you should still be able to use it to run to the corner store, etc, once in awhile, and that will still help tremendously!

[captainslug]

The road performance in the current configuration is pretty bad. A 50cc bike can run rings around this.
The batteries are not up for the demands currently placed on them. I'm wary of how low the voltage is dropping even when the pack is fully charged. If I want to ride it around at all I'd have to drop down to the smaller sprocket and take a big hit in top speed.
Even then the performance will be sub-par for a bike this size.

Originally Posted by Christ

Maybe with the money you save in fuel

One thing this project taught me was that riding electric won't save me money in fuel. The cost per mile is significantly higher because you pay your fuel costs upfront.
Replacing the batteries and the motor is essentially starting this project all over again and I have no interest in spending that much time or money any time soon.

I've learned a great deal and I don't regret this project. All I regret is not having done more research before I started to determine what kind of power requirements are needed to get the performance level I wanted.

[Christ]

Wish I had a project that could use any of it, I'd make an excuse to come down and pick some stuff up/hang out w/ a fellow Ecomodder.

So are you thinking about a V2.0? Or, is it maybe time to work on something a little larger/more versatile? (Or even something just fun?)

[truckncycle]

Captainslug, thank you for sharing your progress and your frustrations. This has definitely been one of my favorite build threads.

[Christ]

Consider this my nomination for project of the year, should that contest come about this year.

If not, great job anyway. Hopefully, someone else pursuing a similar project will learn from your ups and downs along the way, and even if they don't learn anything, it's still an interesting read/follow along, and of course, you learned stuff in the process, right?!