Electric Portuguese Chopper

Discussion in 'Electric Bicycles' started by Bobocop, Feb 9, 2009.

  1. Bobocop

    Bobocop Member

    This is my electric chopper build.
    I started this with not much money to spare (not working at the moment)
    but I wanted an electric bike, I wanted a chopper with a wide back wheel.

    I started searching for a cheap motor, my plan was to make a chain drive (motors are cheaper) but then I came across an e-bike (on the Kijijji website here in toronto) that the front end had caught fire (ignition switch) and the owner was selling it for $50 with no batteries (he had sold them)

    I didn't know anything about hub motors, but it was 36 volts so i decided to buy it, since i was looking for a 24 volt, I thought this would be more powerfull.

    Next, I searched for a wide back wheel and came across a stingray bike selling for $45, (also on the Kijijji website) You can't get just a wide rim for that price, (and there's none to be found).
    I figured I could use the rear wheel, forks, peddles, chain etc, for my build, so I bought it.

    Here is a pic of the e-bike i bought.
    And a pic of the stingray.

    Attached Files:

  2. Bobocop

    Bobocop Member

    The first thing I had to do was try to get the wide back wheel from the stingray onto the small hub motor rim, (or it couldn't be a chopper, with a 12" rim)
    I did merge them, (as you can see in the photo of the e-bike in my first post), so the build went on. (more on the merging of the rims later)

    I started by chopping the e-bike up and using the back end with the springs as a starting point.

    Then I started to build the rest of the chopper frame, I used some galvanized tubing that my perants had left over from when they built some sort of canopy for their grape vine in thier back yard.
    remember, i'm trying to build this as cheap (money wise) as i can.

    For the tube bending (some of you might laugh, But it works great) I welded a scrap bike rim and a couple of forks together, I removed some spokes so it wouldn’t dent the tube.

    I used the fork neck off the stingray bike.

    (I'm trying to put the pics under the explainations, but i guess i can't so the pics will be at the bottum of the posts)

    Attached Files:

  3. Bobocop

    Bobocop Member

    The forks,

    I'm combining the forks from the stingray and the e-bike (the ones that i bought)
    I left the stingray forks length, which is 28", then i cut the e-bike forks to 12", just enough to keep the suspension and to slide into the stingray forks, (as to make a stronger joint).

    The diameters were off, so they didn't fit tight, i had to find a bushing, but that was ok because i wanted it a little longer anyway.
    so i cut a piece of tube off a scrap bike that slid nicely into the stingray forks and the e-bike forks slid nicely into that.

    Then i cut the dropouts off the top piece of the forks (stingray forks)

    Those stingray forks are some heavy duty forks, it took me awhile to cut and grind off the access of those dropouts.

    I only have a drill to do most of my work, i use it also for grinding.
    one thing i like to do is put 2 grinding pads back to back, this way i can get in to hard to get places (grind by pushing or pulling)

    Here's how the forks came out.
    after grinding, i applied primer and some automotive spot putty to get rid of the grinding marks, and cover the welds (I don't like the welds to show that much).

    I hated to put all that chrome to waist so i left the top half of the forks untouched, i'll figure something out to put where the chrome and paint meet in order to make it look better.

    Attached Files:

  4. Bobocop

    Bobocop Member

    The battery box,

    Here i'm trying to make the box flow with the frame, i'm using very light wood, the kind they use for cottage wall paneling, for $5 you can buy 5 - 3" x 16 feet strips at home depot,
    I also picked up some shorter strips (wood) for free at home depot, the ones they use to pile bundles on top of each other, their all over the place, if you ask they will let you have them.

    I decided to do the seat (make it flow with frame) at the same time as i waited for the battery box glue to dry, the battery box bottom will be thicker as it's going to support the batteries from moving.

    In order for the batteries to fit, Incase I use SLA's, (untill I can get a lighter pack) the box had to be at least 6" wide.
    that ment that the box had to stick out of the frame a bit (I don't like that)

    Here's the battery box, (pic below)

    Here's the seat,
    I was surprised how cheap the vinyl was ($5 a square yard)
    (pics Below)

    I am going to make a smaller box right under the seat for a 12 volt pack (maybe nicad) to run the lights, horn etc.
    so in order to get at it i added a hinge to the seat so it can open up to have access to the battery
    (pic below)

    Attached Files:

  5. Bobocop

    Bobocop Member

    I didn't like the way the battery box stuck out of the frame.

    And i needed to add some kind of support for the kickstand and trailer hitch at the back of the bike, (near the rear hub axle)
    The kickstand and trailer hitch are going to be one unit (more on that later)

    Anyway, what I decided to do is add another tube running from the front to back, not only does it make the bike look better (I think)
    But it also makes the frame stronger, and it gives me the support at the back for the kickstand/trailer hitch.

    Plus, if I'm not happy with the hub motor after the build, these extra tubes can also support a chain drive motor just in front of the rear wheel, to help the chopper up hills.
    (pics below)

    Inside the top 4 tubes is where my controller and wires are going to hide.

    The wires for throttle etc. will come in through the front opening of the tubes.
    I drilled a hole on the inside of each tube to fish the wires through.

    Also, I welded a bolt (as you can see in above pic) for the ground wires.
    I'm going to use the frame as a ground for the lights etc. this way i don't need to run all the grounds up to the battery.

    Attached Files:

    Last edited by a moderator: Dec 15, 2015
  6. Bobocop

    Bobocop Member

    I made the side panels to close it all in.
    I'm using that same light wood that i used for the battery box
    (pics below)
    neck 01.jpg

    I had some of the vinyl left over from the seat so i decided to cover the inside with it.
    neck 02.jpg neck 03.jpg neck 05.jpg

    The top panel will be held down with screws

    neck 06.jpg

    Just needs a little spot putty and smoothing out

    neck 07.jpg
    Last edited by a moderator: Feb 10, 2009
  7. Bobocop

    Bobocop Member

    I wish i could put the pics right under the explanations, but I can't (or I don't know how) so, as I said earlier, the pics will be at the bottom of the posts.

    More on the build soon.
    Last edited: Feb 9, 2009
  8. azbill

    azbill Active Member

    'Also, I welded a bolt (as you can see in above pic) for the ground wires.
    I'm going to use the frame as a ground for the lights etc. this way i don't need to run all the grounds up to the battery.'

    dude...you don't want to ground the frame with a hub motor
    it grounds the forks on each side of the motor and it will just vibrate (like it is trying to run both directions at once)
    did it once trying to wire a tail light, almost fried the controller till we figured out what was wrong
  9. srdavo

    srdavo Active Member

    here's a How-To link on attaching pics....

  10. Bobocop

    Bobocop Member

    Thanks for the advice (I didn't know that with hub motors)
    But I'm not using the motor battery pack for the lights etc.
    I'm using a separate 12v nicd pack for that,
    so instead of running the headlight, signals, horn etc. ground up to the pack, I'll just ground them to the frame.

    The hub motor is going to run on a separate 48 volt pack
    Last edited: Feb 10, 2009
  11. Bobocop

    Bobocop Member

  12. SimpleSimon

    SimpleSimon Active Member

    You do VERY NICE work. Seriously, guy, I'd love to see what you'd do with a properly equipped shop and a reasonable budget. If you are looking for work, put together your build log and pics from all along the way, and put it on some CD's. Then go to every custom bike shop in reach and ask them to just look at your work.

    I'll bet you get some offers of a job.
  13. sjacome

    sjacome New Member

    aleluia, até que enfim uma construção tuga por aqui!

    tambem ando aqui a pesquisar para uma construção tuga, mas o mal é que cá em portugal, peças, motores e salvados de biclas tá muita mal e de guito então nem se fala. No canada sem duvida ta-se melhor (para peças - é muito frio para o meu gosto! ;-) ).

    Desculpa lá agoirar mas se o motor hub que tens não é superior a 500w de potencia, acho melhor pores ai uns bons pedais pois vais precisar. Com um etek ou mars sem duvida ficava no ponto mas são motores carotes e precisam de muito sumo (baterias e das boas).

    Diz-se por cá que a necessidade aguça o engenho, e vendo já o que construiste com simples ferramentas, de certeza que vais conseguir levar o projecto a bom porto e em grande estilo.

    para inspiração aconselho-te 2 link's :

    www.ratrodbikes.com (restauro e decoração de biclas)

    www.endless-sphere.com/forums (biclas electricas para todos os gostos - vê a parte das non-hub motor electric bikes - e malta é muito prestativa)

    Desejo-te melhor sorte para emprego, digo-te já que por cá a malta licenciada ta a emigrar para Inglaterra, Irlanda, etc pois isto ta foda aqui, e o pior está para vir.
    Last edited: Feb 10, 2009
  14. Bobocop

    Bobocop Member

    Thanks SimpleSimon

    @ sjacome
    Sorry :evilgrin:
    I can speak portuguese very well, but I can't read or write :evilgrin:
    I came here when I was 6, so I never got a chance to go to school there.

    Thanks for the links thou. I started a thread on Endless-sphere about this, but no one was interested.

    I will check out the bikes on ratrodbikes, looks like a good site.
  15. Bobocop

    Bobocop Member

    I made a rear spoiler for the back.

    Frame 13.jpg
    Frame 14.jpg
    Frame 16.jpg

    As you can see from the pics above i also welded the supports for the kick stand and trailer hitch.
    I just used pieces off of scrap bikes.

    Frame 17.jpg

    I want the trailer hitch to be centered (roughly) with the rear axle, so when the trailer is doing the pushing
    theres no up or down pull, if you know what i mean.
    (the trailer will have a motor, to help push the chopper along when needed)
  16. Bobocop

    Bobocop Member

    The kickstand and hitch

    The reason I did it this way is because when I have the trailer on, I want it (the trailer) to push straight and not with an arm to the side. (I didn't want to get any kind of twisting)

    So I had to make the hitch in the center of the bike,
    Plus I needed a kickstand, so I decided to make it one unit.

    I'm sure there are better ways to do this ( I'm open for suggestions) but this is the only one I came up with.

    Kickstand position

    Kickstand 01.jpg
    Kickstand 02.jpg

    Trailer position
    Kickstand 03.jpg
    Kickstand 04.jpg
    Kickstand 05.jpg

    Tucked away (sort of) position
    Kickstand 06.jpg

    I'm holding it in trailer position with 2 3/8's bolts.
    Kickstand 07.jpg

    I thought about just using sliding pins to keep it in position, but i thought that it wouldn't be tight enough ( a lot of movement and noise while pulling trailer).

    I can thread the bolts in by hand then use a wrench to tighten it from coming loose. ( I'm in no hurry to go anywhere)
    it ends up being solid with no movement.

    I am going to use a caster like this on the trailer side.
    Hitch 01.jpg

    So here i just welded a 7/8's nut.
    Hitch 02.jpg
    Last edited by a moderator: Dec 15, 2015
  17. Bobocop

    Bobocop Member

    I was trying to figure out where to put the peddles,
    I'm using the bottom bracket off the stingray, I cut the sprocket that was on there and welded a smaller one.

    I tacked it on here to see how it looks and i'm thinking of leaving it there.
    Peddles 01.jpg
    Peddles 03.jpg

    I wanted to move it in closer to the frame (so it wouldn't stick out so much) but i can't because of the sprocket.

    I set the seat off of the stingray on there to see which one looks better,
    but i think the one i made might look better on this bike.
    Seat 07.jpg
  18. POPS

    POPS Member

    Very nice build so far. Very Very nice. How are you keeping everything straight as you are welding it together? Are you useing a jig ? You said you are useing galvanized tubeing for the frame. How are you welding it ? It almost looks like solder in some spots ? Tig, Mig ??? I hope you welded that GAL. tubeing outside because the gas that comes off GAL. tubeing is DEADLY! Turns young lungs into old lungs in a heart beat if it doesn't put you in a box. Keep up the good work and keep us posted...POPS
  19. Bobocop

    Bobocop Member

    I don't have a jig, everything is being put together by eye and straight rulers.

    I'm using a flux mig welder,
    I couldn't afford a gas mig so I bought a flux core welder.

    Last summer I came across a (free) broken 18 volt pocket bike so I tried to build a chopper with the motor.
    I didn't have a welder at the time so I bought a can of fibreglass resin and some fibreglass cloth, and with some pieces off of bmx bikes I built this bike


    I hooked up 2 sla batteries to it, the bike rode, but it had no guts. (motor was weak)
    but I liked the idea of having an electric chopper :grin5:, I just had to build a better one.

    So I saved some money to buy a mig welder to make this one.

    Yes, I do have to take the bike outside to weld, and I grind the tube first before welding.

    (This was taken when i took it out to weld the forks and see how they fit.)

    Frame 07.jpg

    the reason it looks like solder is because I grind the welds down to smoothen them out, I don't want the welds to show, so I grind, them then I apply some spot putty.

  20. Bobocop

    Bobocop Member

    Opening the motor

    I didn't like the gauge of the motor wires,
    so I opened the motor to change them and at the same time check the brushes.

    I started by removing the cover on the wire side.
    I removed the brake drum and the cover screws and then tapped with a screw driver the sides of the cover.

    I had to wedge some pieces of wood in between the cover and hub as it lifted slowly, something was tight in there, later i found out it was just the bearing (the way it sits nice and tight in there)

    Motor 02.jpg

    I was VERY surprised on how this motor was so clean when the cover came off.
    (I was expecting all kinds of brush dust)

    Motor 03.jpg

    And the brushes are in great shape

    Motor 04.jpg

    I didn't have any thicker wire gauge that i was able to fit in the hub.
    So I cut the wires that were already there in half and doubled them up,
    Then I put some heat shrink on them and fed them back through the axle.

    Motor 06.jpg

    On assembly I put a small bead of gasket silicone on the cover.

    Motor 07.jpg

    When I went to remove the screws that hold the wires down to double them up, I found that they were loose (the screws)
    I can see how something like this can drive someone crazy trying to figure out why the motor cuts out (bad connection inside the motor)

    I also extended the rear drop outs.
    Because of the tire being bigger then the one that came with the motor, it was almost rubbing at the front (only had about 1/4 inch clearness)
    I didn't want to run into problems later by moving the wheel to far back so I extended it (drop outs) by 1"

    RdropOuts 01.jpg

    Then I primered some of the welds (I don't like welds showing to much) and added some auto spot putty

    RdropOuts 03.jpg

    As soon as the snow clears up outside a bit I'll take some pics of how the bike looks so far.
    I don't have enough room inside to get a complete pic of the bike right now.