Electric Long Bike

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Introduction: Electric Long Bike

I built this electric bike for commuting to work. I stretched the rear triangle section partly because I wanted the extra cargo room and partly because I just liked the look. :-)

Step 1: Cutting and Welding

I started with a few curbside-recycling bikes which I welded together to make a stretched frame. I used a simple jig (made from parts of an old exercise bike) to try to keep things mostly straight ;-)

Step 2: Testing the Hub Motor

This show the initial testing of the hub motor and controller. I'm using a 20Ah 48V LiFePO4 battery, which is not shown in this photo. The hub motor, controller and battery were all purchased on EBAY.

Step 3: Rolling Chassis

Note the 2 kickstands. I need both due to the stretched frame and the battery weight.

Step 4: Final Touches

I'm happy with the performance of the bike. I can sustain 25 MPH with moderate pedaling and I can easily commute the 15 miles (each way) to work and the battery still has reserve charge when I return home. I installed a DC-to-DC converter (from an RC Hobby supplier) to generate 6 Volts to run the headlight and tail-light so all the electrics on the bike run from the 48V battery.

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    user

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    36 Comments

    Nice work! You mention it's a 48V system; what kind of batteries do you use to get that kind of range on it?

    1 reply
    user

    The bike has a 20Ah 48V lithium battery (check EBay). It was expensive, but in my opinion worth it because lithium batteries are much lighter and they last longer than lead-acid batteries. I have never really tested the battery to its limits so I can't say its absolute range and much depends on riding style, terrain, etc.

    This instructable doesn't really tell how to do build this. I'm a beginner and this isn't helping on how to mod a bike into an electric bike.

    How is the light work? Do you have to press some button every time to have it light up?

    1 reply
    user

    The tail light comes on when you turn on the bike main power. The head light comes on when you turn on the headlight. The headlight has flashing and non-flashing modes. Both tail light and head light are powered from the main battery.

    user

    The hub motor itself was about $100 without the rim or spokes. Adding a good quality rim and spokes and labor to lace the wheel pushes the cost to over $200 for the completed rear wheel.

    Our hub motor is much cheaper than your price,if you want to buy next time,you can contact me.

    Where can I find hub motor?

    user

    You can find them on EBay .. and there are a number of other places where you can buy them online .. try a google search for "hub motor kit" ..

    Scd,you can use the water bottle battery or hub batter pack.

    Scd,you buy the spoke motor from golden motor?You are very good,you install the e-bike by yourself?
    We are the manufacturer of the e-bike conversion kit,if you need,you can contact me.

    has the frame cracked yet? i can't see how the load could effectively be transferred to the rear wheel.

    2 replies
    user

    The frame is strong and shows no signs of cracking

    Great instructable, I'm very happy to see how many people are using motorized bicycles to supplement or replace their dependence on cars.
    I do think that dogbeardbirdbeer has a point, in spite of the gruffness of his comment. Due to the lengthening of the frame, the bicycle is structurally weaker than it was originally. Specifically, the area between the seat post and the rear tire. You might avoid future problems by adding a pair of additional braces. I'd say the most efficient placement would be to divide the rear parallelogram into two triangles. In a line similar to the top/front of the rear tire. Just a thought.

    Is that a 1KW motor?

    I've got a kit from eBay, but I'm concerned that it would not be road legal?

    2 replies

    It depends what state you live in.

    In "Florida", any motorized vehicle needs a license and a plate for a motorcycle. Since there is a second law that states it is illegal to drive any motorized capable vehicle on sidewalks. (Even if you do not use the motor, it is motorized.) Thus, you are left driving on the road, and driving a motorized vehicle on the road requires a license and a tag. The only license and tag allowed on a non-car, is a motorcycle license and motorcycle tag.

    Thus, any motor is legal, as long as all other road-vehicle requirements are met. (Mirrors, signal lights, breaks with adequate stopping power for the drive-system, helmet, and break-lights.)

    Most states have similar DOT laws. Few states allow motorized vehicles on sidewalks, and most demand similar requirements for motorized vehicles on the roads. Just because you can't find the laws, or because you haven't been caught yet, or they don't actively enforce them... does not mean they don't exist. Ask your insurance company. That is when laws get actively enforced 100%. On the road, it is a lotto gamble.

    BTW, Nice setup.

    i read if it has pedals on it with chain still attached it is.

    if you dont mind me asking. minus the bike how much did all this cost?