Golf cart based electric motorcycle build. - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum

Ryland · 03-07-2010, 11:50 AM

The engine is out, took two of us around two hours, we got the engine out in the first hour, the 2nd hour the friend that was helping me pulled the air box and a few other odd parts that we don't need any more while I stared at the engine and frame scratching my head, turns out the drive shaft floats around in the swing arm, I thought there was a support bearing at either end of it, not the case, so we did some redesign of the motor bearing plate, adding another bearing, so the shaft that connects the golf cart motor to the motorcycle is ridged enough to support both the open end of the golf cart motor and the unsupported end of the drive shaft/U-join, the advantage of this new twist is that because the drive shaft in the swing arm is unsupported I can tweak it's exact location by a small amount, this turned out to be needed when two bolt holes crossed paths.
The plan for the day is to make a wood mock up of the bearing carrier that also is one of the main motor supports and make sure that clearances are correct before I have my brother write up the CNC program to make the part as there are some curves in the bike frame that make it tight and hard to measure.
I still have not started on specs for the adapter shaft that connects the motor to the motorcycle, but we are getting close, then the motor can be bolted on to the frame and tested.

Ryland · 03-10-2010, 01:37 PM

Due to some alinement issues I had to change my motor mount design, not a great deal but enough that I had to make a trip to buy more aluminum stock, so instead of the motor bolting to a 3/8" by 8" plate, it gets a 3/4" by 6" plate to bolt to, this will be much stiffer and the added thickness allows a bearing to be pressed directly in to the plate that is bolting to the face of the motor, reducing the number of machined parts and reducing the number of bolts needed to hold it all together, by tomorrow at the earliest or this weekend at the latest I should have the motor to a point where it can be bolted on, no splined shaft yet, but that is next on the list! once the motor is bolted on I can start on the battery rack design and figure out for sure how many batteries can fit in the frame, there is more space then I figured at fist and the engine weighed what seems like close to 200 pounds, enough that I needed help moving it so I feel pretty good about the bike being able to handle the weight of the batteries.

Clev · 03-10-2010, 04:28 PM

Pics, please!

Ryland · 03-10-2010, 08:05 PM

Quote:

Originally Posted by Clev

Pics, please!

There is not much to look at yet, mostly a stripped down frame, a motor, some chunks of aluminum and a pile of paper with drawings and measurements.

I did however do some measurements of the frame and the open space and it looks like I should be able to fit 6 T105 golf cart batteries in there without any issue, that is 402 pounds of battery, with the open frame design like it has I'll be able to make a battery rack that sits as low as the engine did, giving me a lower center of gravity, the space under the seat, where the air box sat is 1/2" shy of what is needed for the hight of a T105 battery, otherwise I could fit another in there, one idea is to put saddle bag style racks on the rear for a battery on either side so I can get the full 48 volts I was hoping for, otherwise I could go with a higher voltage battery but I already have 8 used golf cart batteries, lucky for me the motor is designed to spin at around 2,000 RPM with 36 volts and with the gear ratios I have that gives me 57mph, up the voltage and I up the speed.
To give you a taste of the kind of parts we are making to fit this together, here is a bearing carrier that is being put on a shelf due to one of the redesigns I had to do.

The new one looks very much like that but with tabs top and bottom to attach to the motorcycle frame, thus cutting down on the number of parts needed.

Ryland · 03-13-2010, 11:12 AM

I don't have the drive shaft hooked up yet but the motor is pretty close to being able to be bolted in place, it's close enough that I was able to do a mock up, I was also able to take some measurements and everything is still looking good.

And a close up of the motor.

I don't have the drive shaft made yet but the but I now have all the parts to bolt the motor on, a little bit of tweaking to make the motor fit better and I'll move on to the battery rack.

orange4boy · 03-13-2010, 01:56 PM

Excellent!

My bike has a drive shaft too. it will be interesting to see your solution.

Am I seeing that right that you have no reduction? I guess the low rpm of that motor makes it do-able for a shaft bike.

Clev · 03-13-2010, 02:14 PM

Nice fitment; like the bike was made to be electric.

Ryland · 03-13-2010, 08:03 PM

At one time I found the ratio of the rear gear reduction but I can't find it now, just spinning the rear tire and watching the UV joint spin it looks like a 2.8:1 ratio or so and that sounds about right, either 2.8 or 2.85:1, not sure what other shaft drive bikes run at, but with a bike that has close to an 80" circumference on the tire it seems about perfect, also if I want a faster bike 3,200-3,600 RPM motors are pretty common, as I said before I can even get an affordable 3 phase motor and I think a used golf cart motor plus the CNC parts and adapter shaft is going to cost less then a new Etek motor and should give you more power.
Oranage4boy, what bike are you going to use? I might have some odd parts left over once I'm done if you want to pick up a golf cart motor as well.
My other brother shows some interest in this project as he is looking to buy a motorcycle this summer and said that as long as it goes "fast enough" he would think about it, so I might have a 2nd one going right away if this one doesn't have any weird bugs.

Clev: After seeing what kind of issues this motorcycle has with it's gas engine and doing research on the rest of the bike I would get more and more excited about it every time I would find more info about it to the point that I would get giddy talking about it or even just thinking about it, like that the frame opens up once the engine is removed, the rear gear ratio is near perfect for an electric motor, the fully dressed bike is big and heavy so a striped down version should handle great with batteries, it's really common with new and after market parts avalible, as it really is the perfect bike to be electric, it just needs a handful of odd parts to make this weird motor fit.

Quote:

Originally Posted by orange4boy

Excellent!

My bike has a drive shaft too. it will be interesting to see your solution.

Am I seeing that right that you have no reduction? I guess the low rpm of that motor makes it do-able for a shaft bike.

Clev · 03-13-2010, 08:55 PM

This is the bike I always wanted to convert:

Honda Pacific Coast - Wikipedia, the free encyclopedia

Fairly porky because of the large V-Twin and liquid cooling, but it has the advantage of shaft drive, 988 lb. gross weight rating and a lot of room under the bodywork. Ah well, some day...

mechman600 · 03-15-2010, 10:59 PM

If I can offer some simple advice:

The engine you pulled out of your Honda is a stressed member, an integral part of the frame/chassis. Make sure you [very] solidly connect the two engines mounts back together when you are finished. A solid connection between the headset (upper engine mount) and swingarm base (rear engine mount) is mandatory, or your frame will snap like a twig and hurt someone.

Very cool project. I've always wanted to attempt something like this with my CB400T2.