My ELECTRIC homebuild

Discussion in 'Photos & Bicycle Builds' started by veloman, Oct 21, 2008.

  1. veloman

    veloman Member


    24v system
    2 x 17ah SLA batteries
    600 watt (864 peak) electric motor made by Currie
    15 x 80 gear

    Bike is a no-name singlespeed road bike I got off ebay for $250.
    Bike is able to be pedaling, but the motor hinders the left pedal stroke (must use heel of foot!)


    Cruises easily at 24mph on flats.
    Top speed of 33mph (with a little help getting it up there).
    Goes up 8% grade at 20mph with moderate pedal assist.
    Total bike weight 70lbs.
    Accleration is modest, but with a little pedaling it quickly gets into the 20s. Might be a little overgeared, but I am currently trying to find a 90 or 100 tooth #25 sprocket that will fit on the mechanism/axle.

    Cost: $600 including bike

    Noise: What noise?! Just a very slight hum, very quiet chain in fact.

    Motorization is completely homemade and all me. Just a hack saw, drill and small hand tools! Yes, that is a lunch box holding my batteries, it works perfectly! haha


    Attached Files:

  2. brisbane_boy

    brisbane_boy Member

    nice looking bike,
    Iv been looking at the electric bikes.
    How long does the battrey last?
    well done
  3. rkbonds

    rkbonds Member

    Cool set up what are you using for speed control and how do you have it all wired? Could you post some more pics of how it's all set up? I would like to build an electric for myself, I just need to see how one is put together first.
  4. veloman

    veloman Member

    I have a twist throttle, which came with the matching controller and motor.

    I did have to switch the motor wires to get it to turn in the right direction, but other than that it's very simple. 2 12v batteries wired in series to equal 24v. Not much to it.

    However, I would not recomend this motor placement, it took a long time to get it right and it's far from perfect. Unless you're quite mechanically inclined the best bet for electric is buying the hub motor wheel system.

    The other issue is the mounting of the sprocket. I needed a fixed gear bicycle wheel so I could screw on the freewheel mechanism which holds the sprocket. I used extra long bolts on the sprocket, and they in fact DRIVE the rear wheel by contacting the spokes. There really wasn't any other way unless you use the right side drive where the threads on in the correct direction.
  5. rkbonds

    rkbonds Member

    So was it a kit? I thought it was something you pieced together. I'm not wanting to buy a kit I want to figure out how to do it without a kit.
  6. veloman

    veloman Member

    No it's not a kit. I just got the controller, throttle and motor together. Or you can buy them seperately, but that's harder. Check out
  7. rkbonds

    rkbonds Member

    Thanks, I'll check it out.:cool:
  8. bluegoatwoods

    bluegoatwoods Well-Known Member

    That really is pretty impressive.

    I'm proud of my MB. But when it comes right down to it, I didn't do the hard part (engineering).

    You did. Good for you!
  9. veloman

    veloman Member

    Thanks blue, it definitely makes it more fun to have designed it yourself.
  10. InfoCentral

    InfoCentral Member

    The problem is the range per charge.