Lightweight Electric Motorcycle With Bamboo Frame

For our high school senior project, we have created a bamboo electric motorcycle. This project has been extremely fun, challenging, and time consuming; this is not something you can do over a few weekends. The end goal for us was to create a working motorcycle with a bamboo frame and an electric motor, as well as to create an Instructable.

 The main stages for this project are:

1. Setting your goals for distance and speed and creating a budget.
2. Researching and ordering drive train parts.
3. Testing the drive train
4. Creating a model in SketchUp
5. Obtaining and heat treating your bamboo.
6. Hacking apart your donor bike
7. Tacking the frame together
8. Epoxy-ing  the joints
9. Creating mounts and attaching the drive train.
10. Wiring.
11. Final parts and safety checks.

 

Materials:

            Bamboo (more than you think you need)

            Hemp twine (or some other sort of absorbent twine)

            Epoxy and hardener

            A donor bike frame w/ fork

            Hot glue sticks

            Pipe clamps

            Zip ties

            Lugs or some other connectors (for wiring)

            Electrical tape/heat shrink

            Plywood (inch thick and ½ inch thick)

            Rubbing alcohol

            Solder

Tools:

            Hot glue gun

            Drill (a drill press is nice in addition to a drill, but you don’t need one)

            Hack saw

            Wood saw (a band saw speeds things up a bit, as does a circular saw)

            Jig saw
            Screw driver (Phillips and flathead)
            Computer w/ SketchUp
            Rubber gloves
            Ruler
           Sharpie
           Clamps
           Soldering iron

Parts:
           Electric motor
           Batteries and charger
          Controller
          Throttle
          Bicycle breaks (front and rear)
          Bike wheels and tires (front and rear)
          Handlebars and stem
         Two switches (one for controller killswitch, one battery circuit breaker         Rear sprocket (match pitch with motor sprocket)
         Chain (match pitch with motor sprocket)

Step 1 Setting your goals for distance and speed and creating a budget

Setting goals for distance and speed will help dictate your parts and budget. As an electric motorcycle, it won’t be particularly speedy unless you get a very large motor. Realistically, the top speed for this project should be somewhere between 20 and 40 mph, depending on gearing and motor choice. The upside of this is that depending on where you are living if it goes under a certain speed you do not need to get it certified to ride it on the streets.

For our project, we set the goals of a 25 mile cruising range and a 25 mph top speed. Because of some gearing complications we actually ended up with a top speed of around 35 mph.

Our budget ended up being around $1100, including one blown controller and a few tools we didn’t have already. Your budget will most likely be your limiting factor. It will determine the size and power density of your batteries (your most expensive part) and how powerful your motor is. It is important that you leave an extra couple hundred dollars in your budget for unexpected costs, because who wants motorcycle that almost runs?

Comments

[sevakkishan]

nice

[electric eric]

My longest trip on this bike was a 42km. The bike weighs a total 38kg due to the weight of the hub motor and the batteries. The 3 batteries by themselves weigh 12kg.

[electric eric]

/You may be interested to see our electric bamboo bicycle. we call it the electric eric 350. the motor is 36v 350W brushless motor. The main triangle is made of natural bamboo and the chain stays and seat stays are made of laminated bamboo. The " lugs" are made of epoxy and abaca fiber.

[tazerl494]

what cad program do you use? also check this battereys out: http://www.hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=14476 2.45 amps at 30c this can crank out 73.5 amps XD

[niuthon]

nice
but for so expensive and efficient batteries, you have chosen crap motor.
in my bike range was doubled (or tripled)(on the same batteries) when i changed brushed motor like yours for brushless hub motor (both were 250 W)
almost no noise, no overheating.
So i suggest for everyone - choose brushless motors if you can

[Bay School]

 Where did you get your motor? How big is it? We would have gone with brushless, but there were budget constraints... 

[niuthon]

i get mine from someone on our version of ebay for about 150$ with cotroller, but they are nearly unobtainable in my country, new one can cost as much as 500$.
My brushed motor with chain drivetrain achieved only 5 miles range , it  was 250 watt motor for electric scooters.
Brushless hub motor ,also 250 watt, was much bigger and heavier , but had no drivetrain (it was hub motor just as an average one one you can see on youtube these days). And there are no batteries other than lead-acid available, so i ended with  15 kg (~30 lbs) of batteries for  22 km (~15 miles) range.
One year ago it was something of a novelty in my backwater country, so my proffesors constantly asked me how my bike works.
Anyway, it seems for me that brushless hub motors are most efficient for bicycles.

[greatpanda]

Here's some data I've been waiting on for years: how far can it go on a single charge?  How is the motor mount holding up to the torque?  I never could find reliable data when I was planning on doing this back in high school, so it kinda got back-burnered since I didn't know if it'd go at least a mile or two.  


It seems that the batteries might be more easily stacked vertically if the cross piece weren't there, might be an argument for a metal frame.  Maybe I'll try it with the rest of the gearing left intact (so the bike ride doesn't have to turn into a walk once you run out of juice), I'll let you know how it turns out.  Who knows, maybe even a small dyno in series for the downhills?

[Bay School]

 The distance on a single charge is at least ten miles, maybe double that, depending on how the engine holds up. Overheating turned out to be the biggest issue with the bike. The motor mount we have is actually incredibly solid so far, but we'd recommend using bolts instead of screws to hold it in. 

That crosspiece is absolutely necessary, as far as structural integrative goes. It would be a different project if the frame was metal; the bamboo frame was super light and a metal frame would require a much more beefy engine. 

I strongly recommend against trying to work multiple gears into a project like this, because electric engines completely tear apart any conventional gearbox. 

Good luck on your project, and don't forget about engine cooling!

[greatpanda]

 How much does it (the frame) weigh?  My understanding was that bamboo is actually comparable to aluminum for weight.  

Don't worry, I wouldn't dream of having the motor drive a gearbox, I'd just leave the existing gears intact and drive the wheel from the "wrong" side.  Perhaps an air scoop for the motor to help cool it, since it won't generate any heat while still.

[Bay School]

We didn't weigh it, but the bare frame was super light... Definitely comparable to aluminium. 

[TSC]

Sweet!!!!!!!!!! cool!!!!!!!!!!!!!! 5STARS

[mycroftxxx]

 I realize that learning and mastering the technique of bamboo bike-making is more valuable than an individual frame, and that the motorcycle frame is vastly different from the bicycle frame you salvaged parts from - but it always pains me to see one of the steps for these instructibles be "tear down a functional bike frame".  

I know nothing about bike construction, but is it possible to acquire the necessary parts for the connectors from non-bicycle sources?  (This is a genuine question, an answer of "No" or "Not safely" is fine, I really don't know.)

[Bay School]

 Yes, it is technically possible to acquire individual parts, but it's vastly more difficult to construct  something usable out of them.
We were originally going to make the rear triangle out of bamboo, for example, just using metal dropouts, but then we wouldn't have been able to mount rear brakes (ya can't drill into bamboo). 
As far as a waste of a bike frame goes, we encourage people to use a bike that's destined for the junk heap anyway. It's not the most ecological thing ever, but it's a lot safer unless you're already experienced in working with bikes. 

[mycroftxxx]

 That's about what I expected.  I was guessing it would take several major bamboo-bike factory opening up for the attending bike parts industry to start supplying the necessary metal bits.  Ah well.  

Is there anything you would do differently on electro-bamboo-bike 2.0?

[Bay School]

 Ha, I sort of had to write a paper on your question, but the gist of it was this:

• Suspension on the front fork (wouldn't be hard at all, we just need the right fork)
• Waterproof (We'd probably use plexi and lots of hot glue)
• Real bike seat
• Gauges (speedo, engine temp, charge level)
• Some way to cool the engine 

[tazerl494]

nice bike!
just tow questione,
one, what is wornge whit just puting this system on a normal bicycle! no offence intended!
and how did you make the foot pegs!
thanks so much!

[Bay School]

 1. This system wouldn't fit on a normal bike... Aside from the pedals being in the way, this bike is actually a bit longer than your basic road bike. Also, structural stability would be an issue. 

2. The foot pegs consist of one piece of bamboo zip-tied to the bottom of the frame. It's not, um, optimal. 

[discontinuuity]

Why the mis-matched wheels?

[Bay School]

We initially had a knobby tire on the rear, but it interfered with the chain line. We then got the skinniest tire we could find, just in case. 

[nolte919]

In step 2 you say "Two 24v 20ah LiFePO4 (Lithium Iron Phosphate) batteries in parallel"  I think you meant in series, not parallel.

[Bay School]

 You're right, thank you. Fix'd.

[Mr.Sticky]

Nice 'ible.   Two questions though...why did you decide to use a bamboo frame?  And where did yoyu get the 48v motor?

[Bay School]

 We chose bamboo because it's light, sustainable, and doesn't require welding. Also, it's kinda cool.

We got that 48v motor from ebay. I checked again recently and couldn't find that exact motor again, but I did find a number of suitable replacements.

[Mr.Sticky]

*you*