48V Electric Flat Tracker

About a year ago, my dad and I had the idea to convert a beach cruiser bike into an electric motorcycle. We purchased the bike and all the parts necessary and got to work. We modified the frame and rebuilt the bike from the ground up. When we finished, we were extremely satisfied with the results - a 48 volt, 15 horsepower board track racer.

Step 1 The Components

We started with a Felt beach cruiser because it had the right look. We wanted a beefy bike that could fit all the components. The goal was to keep the center of gravity as low as possible. Here are the rest of the main components we purchased:
- Briggs and Stratton Etek motor (now discontinued)
- Alltrax AXE 300-amp programmable controller
- Magura 0-5K ohm twist-grip throttle
- 4 x 12V, 21Ah sealed lead acid batteries
- Avid BB7 mechanical disc brakes (160mm rotors)
- #35 moped chain
- 13-tooth drive sprocket
- 66-tooth rear sprocket
- big power switch
- 300-amp fuse
- 8 1/4 in. stainless steel motor mount (this replaces the original bottom bracket)

Comments

[1up]

Without a doubt, the nicest electric bike I have ever seen. Amazing work.

[iminthebathroom]

When I talk about instructables to people, I use examples of exceptional work to illustrate it orally to them, yours is one of the ones that tops the list!

[rangerweavere]

With the amount of speed that you claim for the EV-12 to reach you would have to get it registered as a motorcycle or risk the possibility of large fines and possible jail time.

[isaacwilk]

If you're not driving on roads you don't have to register anything.

[Davidfromcali]

If that really puts out 15 horsepower it is way too much power for a bicycle frame, chain, brakes, and wheels. That would be enough to hit over 60 mph. Extremely dangerous. Simply becuase the parts fit doesn't make it safe. Crazy.

Nice looking.

[FurtherThanTesla]

I want to make a solar racer with that motor setup, and was wondering- Whats the gear ration on the sproket and motor? and how much was that particular motor?

[LiquidLightning]

13 tooth drive/66 tooth wheel sprocket. 5.08:1 ratio.

[PyroBuilder15]

The new version of it is about $450 USD, i found it here, http://www.robotmarketplace.com/products/ETK-ETEKR.html
You might be able to find it a bit cheaper somewhere else though.

[FurtherThanTesla]

Ive seen similar Perm Mag DC motors on ebay for upper 200's

[BIGHAIRYDUDE]

you know you have the front fork backwards but overall nice

[sovereign]

The fork is actually the correct way, or else the brakes or bike wouldn't work.

[BIGHAIRYDUDE]

but isn't the ark supposed to be on the front

[ComixDude]

i am sure someone already asked but, how do you charge them ?

[akshay2219]

What's the torque rating of the motor???

[JackME]

I am new to this but am really keen to build a electric bike as project and now seeing these results has motivated me more seeing what can be achieved.

Specifically what is the process with connecting the batteries to the motor, I know it has to go through a contactor, then a controller and a fuse in somewhere but I have no clue where to start about sizing all of these components. Also a programmable controller was used here, what programming was required to make it work?

PS, that bike is very impressive and I am very jealous!

[nay52]

I really need to build a bike like this to get to work . Anyone have other plans for an electric bike? Ive seen in magazines a 500 watt electric motor that goes up to 20 mph and if you pedal also, it goes faster. It has a detachable 36-volt lithium battery that lets you go 30 miles on. Where do you get theses parts (battery and motor) ? Thanks

[Matt Carl]

How did you cut the aluminum and attach it to the bike?

[blindflacker]

Need some copper to dress it up. Nice project.

[skaterqwertyuiop]

This is an awesome bike. As a mountain biker I'm loving the avid bb5s. Great bike man. You should get a full face MX helmet, it'd look totally BA.

[pointlessmaster]

I found some dual rotor hubs at this site:
http://www.choppersus.com/store/category/3/20/Hubs-Wheel-Parts/

[merlin2049er]

That's awesome. I'd consider putting one together.

I'd consider a 29er frame, and maybe a shaft drive transmission system.

[A-Nuke1979]

Very cool! I love the 20's/30's retro flat track look. The V-twin arrangement of the batteries worked out perfectly. I'd buy one of these if I found one (or make it if I had the time)!

[tsagert]

The looks of the bike really got me on this. Love it.

Do you have the brakes adjusted like a vehicle to prevent fishtailing? Rear first, then front, increasing in proportions until max braking power? Or does it not weigh so much as to be a worry?

I might make one similar to yours, I like the center-motor design and battery setup. I'd also like hydraulic brakes with a proportioning valve if the combined weight wouldnt affect the range too much. Thanks!

[jongscx]

Bikes Typically have 2 brake levers front and rear independently... They make Hydraulic bike brakes, but from what I've seen, they too are designed to be independent of one another.
Even Motorcycle brakes are setup this way, except the rear brakes are controlled with a foot pedal as the Left hand lever is used for the clutch.

[jdogtotherescue]

This thing is the coolest. I want to make an electric car but this thing is so cool maybe i want to make one like this. i love the style of it. it reminds me of those old motorcycle races. it has the same look. you just need a leather helmet and some retro goggles.

[fullmetal88]

Why did you call it the EV-12???

[joehudy]

i hade the same idea only the moter wase a scooter moter and a speed controler.thats very depresing i thout i wase the only one with that idea and i cold call it my own.bout i havint bult it.its nice to know that it workes and its contest worthy.

[wkumtrider]

I'm a big mountain biker, and in my opinion the hydraulic brakes are much easier to adjust than the mechanical. They are lighter too. I have Avid Juicy 5 on my mt bike.

[abikerider]

My '05 Specialized Epic comp came with the Juicy 5's and they were nothing but trouble. The rear one kept getting sticky and would rub to the point that it was like I was constantly applying the brakes. The shop replaced the levers and the caliper and it kept reoccurring. Then I decided to rebuild them myself with all new seals with only temporary improvement. I finally switched to BB7's and have had no problems since. I think the BB7's have plenty of power if you have decent hand strength. Also, I disagree that Juicy 5's are adjustable. They are not. The Juicy 7's are adjustable. I think it was a smart choice going with the BB7's.

[NeeTo0]

Heelo , my name is victor , i'm from brazil , I wonder where you got that engine, I was very interested in your project, I would mount one more for me I do not know which engine to use, help me please !!!!!!!!!!!

[norrisj]

How much did it cost?

[Tinworm]

hi (this is my maiden posting!) according to a site I just saw, in order to be street legal in the UK (without need for insurance, MOT, TAX and helmet), an electric cycle must be capable of being pedalled without the engine, have an output of no more than 250watts and a maximum speed of 15.5mph under power. I love this project. It looks superb, but I presume that in the UK you would need to treat it as a motor vehicle and that it would then be subject to all the usual bureaucracy?

[dasimpson1981]

this bike in the uk from what i know would come under the 125cc category for horsepower it would also need an sva test befor it could be taken on the rode

[I8mAll]

Concentrated Art is what this is. Buckminster-Fuller said "If it looks elegant, then it's probably right'. This thing ticks all the right boxes. My Compliments...

[rybokc1]

I definitely agree this is a great look for an electric bike. I wonder about leaving the batteries opena nd exposed though. Any dieas on building casing around the batteries without making it too bulky (likely also packed with foam to keep them in good shape)?

[rybokc1]

You know what would make this bike even more practical is a solar recharger. I live about 8 miles from my work. If I could take this to work, leave it outside in the sun knowing it was recharging, that would really be something! I would feel comfort knowing that my bike was recharged (maybe not fully - but enough to replenish some of what I used to get there).

[taiden]

I love the bike. I love the vtwin look. I'm curious how much you estimate the whole project cost? Not including labor of course.

Also was it MIG or TIG welded?

Best wishes,
Luke

[cody777]

it looks like stainless so you need to tig weld it

[taiden]

You can MIG and even stick weld stainless steel. That is a common misconception about stainless. :)

[cody777]

how much did this cost