Motorized Pedal Truck!

Discussion in 'Photos & Bicycle Builds' started by FireBellyCycles, Aug 12, 2009.

  1. I started this past week building a sidecar bike to be powered by a Subaru Robin motor. The idea was to have a rediculously utilitarian grocery getter/ bike hauler/ building supply transporter/ 3 wheeled truck!

    I'm happy w/ how it's going and excited to take it further. I plan on making a transmission for the Subaru motor and jackshafting it! Gonna try for 16-18 speed i.e. hi and lo 8 or 9 speed. I love the size of that motor and decent HP.

    So anyway here's the 1st pics before paint.

    Attached Files:

  2. Progress

    So its starting to come together I thought it would be fun to post a sort of start to finish chronology of the build.

    paint is on, disc caliper now mounted to sidecar. B72 Brooks saddle, heavy duty wheels and other periferies are coming together.

    One nice thing about the compact size of the motor is that, I think, I can run a regular width spindle and crank for the jackshaft. if it is too cumbersome I'll use the wide one.

    So anyway here's where it stands now.

    Attached Files:

  3. crgintx

    crgintx Guest

    From my experience with trailers, both bike and auto, you should have used smaller diameter tire with axle centerline that's lower to the ground. I'm not sure how it's done with side cars. I'd get the widest tire/wheel combo I could fit in your bike frame if you plan on hauling any serious weight with 12ga spoke at minimum.
  4. Yeah, w/ sidecars on m/c's they usually have the same size wheel and those are 11g spokes. It should be noted that sidecars are essentially a failed design. They don't really turn well in either direction w/o a monkey to shift their weight around; you have to slow way down for turns. This is a project for fun. To build something that's fun to go get groceries w/ or haul heavy stuff w/to show how much work is possible from a little motor on a bicycle.

    If one person laughs w/ me it was all worth it!
  5. srdavo

    srdavo Active Member

    YES.... my sentiments exactly!!
    here's my fun sidecar, from a couple years ago....

    I still have it, as a piece of 'yard art' !

    It could be put back into use at a moment's notice!!

    Enjoy!! :D
  6. I laughed w/ you srdavo! For sure, that bike is a beaut (been a bigtime ratbike fan for a long time)!
  7. javelina1

    javelina1 Member

    Dude, insane!!! (I love it). Good luck with that project.

  8. give me vtec

    give me vtec Active Member

    this is great!!! How well does it work... any new pics w/the motor on it????
  9. Hey thanks! it's on the back burner right now but I'll likely have it going for spring!
  10. SimpleSimon

    SimpleSimon Active Member

    Given any thought to articulating the mount to the sidecar frame, so that the bike can still lean into turns? There is a pic of a bike like that floating around here, set up as a flatbed cargo hauler. I did a design study for a similar type arrangement using a crank forward cruiser type frame and powering the sidecar side - done properly it's remove four bolts and you have your cruiser bike as a two-wheeler again.

    Could have set up the powered side on the bike proper, but I got interested in the dynamics of powering the sidecar side. The geometry is straight forward, the load capacity is high, and it would lean through 30 degrees either side of vertical for cornering.
  11. fasteddy

    fasteddy Member

    Simon, building a side car as we speak and will power the side car with a hub motor.
    Electric is mandatory here in British Columbia. The option is a $5,00 fine and 2 years in jail max.

    Bike is a 50's Monark and I'm planning to hinge the side car so it will lean with a rod from the seat post to the side car frame that will stop movement at about 35 degress.
    I am losing the use of my legs slowly and my balance isn't a lot better and I hoping that having something to stop me from going past that angle will help.

    Think a 20 inch powered wheel will work and help lower the center of gravity for the side car. The side car is almost complete and then it's on to the frame.

    Your thoughts are most welcome.

  12. SimpleSimon

    SimpleSimon Active Member

    FE, I'd be very interested in seeing what you are building and the bike it is intended to attach to.

    Going with a 20 inch wheel on the sidecar very slightly changes the geometry of articulating the sidecar to allow leaning, but it isn't really a problem. Since the nominal axle height on the sidecar side is 10 inches, and the axle height on the bike is (I assume) nominally 13 inches, turns at full lean into the sidecar attachment side will tend to cause your drive wheel to hop unless you have a significant mass of battery weight below the axle height, depressing the CoG. Putting the majority of that mass at the end of that lever arm will also help a great deal.

    Post some pics, please, if you got them. I have often thought that for e-bikes to be practical, they really need to be trikes (to enable carrying sufficient battery mass to give a decent range. Doing that through a sidecar actually makes good sense.

    I know a gent in eastern Washington who is a recumbent fan, and is an electrical engineer for the BPA as his career. He built a tadpole trike with a battery pan below the main boom, giving him 4 inches of ground clearance, and a 240 mile range. We have been discussing building a delta full suspension trike, with independent swing arm rear suspension and enough battery capacity to go 180+ miles on a full charge, at an average speed of 25 mph. I am doing preliminary sketches - once he gets back to me with his load and distribution numbers I'll do a full on design study and generate plans/specifications.

    So, yeah, I'd like to see your project.

  13. fasteddy

    fasteddy Member

    Patrick, I'm just at the point where I'm putting the body together. Looks like a Chris Craft run about.

    I am going to hinge the bike and the side car but not the side car wheel. To many cables running to it and I have been warned that if the wires are pulled loose the game is over. The wheel is around $500 with taxes so I tend to be careful.

    I'll start welding things up this week so as soon as I can I'll send you pictures of what I'm building. I think the side car/frame is going to be about 75 pounds without the wheel and battery/charger.

    What batteries did he use to get a range that long?
    We have a well respected e-bike co. in Vancouver 35 miles away and part of my discussion with them has been using Lithium-ion Polymer batterys. Not inexpensive but compact and longer lasting than the lead acid batterys.

    We are allowed 20 miles top speed for ebikes so distance is more a factor. My tired old self is going to be good for about 20 miles and by then if I haven't fallen off I will be ready too.


  14. SimpleSimon

    SimpleSimon Active Member

    His battery pack on the tadpole was Lithium ion polymer batteries cells set up in series to produce 36 volts - if my memory serves me there were a total of 8 packages in parallel to get that range. All the batteries were contained in a weather proofed underslung "floorpan" under the seat and chain run. I do recall that he was using a Currie motor and Sturmey-Archer internally geared hub as a "mid-drive" where the powered and pedalled drive trains came together.

    I need to re-read his e-mails describing it. I'll ask him again if he wants to join here, or if I can have his permission to post some pictures he sent me of that bike. When I first asked him about joining here he indicated that he isn't really interested in the internet, and most of his involvement with it is work related. I've known him since he was the 6 yr old brother of a girl I dated in high school - I gave him his first bicycle, and when I was in college I was one of two "adult" leaders of a group of 7 grade school boys on a bicycle camping trip to the Oregon coast that was basically him and his friends. I was the slave driver of that bunch - I told all the kids that no one was going on the trip who wasn't riding his bike at least 25 miles a day, and who could do a hundred mile day and still function. That was in May of '75, the camping trip was in mid-August. Of the original group organized, three dropped out, leaving 7 boys and a friend and I for the weeks trip. That was a lot of fun.

  15. fasteddy

    fasteddy Member

    The powers that be here, have said no gears run by the motor. It's a motor assisted bicycle period.
    The battery here {36V} is $815. He may have made his own up out of individual cells as many do. The battery I'm looking at is in an aluminum case and contained in case of fire.

    From what I understand they are not to be taken lightly. They do not like to be mishandled or the fire works are spectacular.

    Would certainly like to hear what he has done.

  16. No on the articulation for this one! like the idea but not settled on a particular design so this one is rigid.
  17. I have a supposedly good source for li-ion batteries direct from china. Not on this comp so I'll post a link later.

    Like what you guys are up to, don't mind this thread drifting so feel free but if you start a thread on the BC build pm me w/ a link, if you would, so I can follow. Thanks!