80cc quadricycle consept

Discussion in 'Photos & Bicycle Builds' started by nishikidrift, Sep 13, 2015.

  1. nishikidrift

    nishikidrift Member

    [FONT=helvetica, arial, sans-serif]An idea came to me: take two bikes that are the same, weld them together, add an engine, rack, and pinion steering? I would have it top out at 20mph with the single gearing so it can traverse portlands hills. i think i could do it for under $1000.00 (most of the cost would be labour) minimum $800.00. the bikes, twin bikes, are at walmart for $50.00 x2 the cheapest they have, the engine kits are on ebay for $135.00 @ 80cc, that leaves a few hundred for materials, steering, and miscellaneous parts like head and tail light. for the torque i would either use 20 or 24 inch wheel frames maybe 26's in the front with one electric hub wheel.[/FONT]

    [FONT=helvetica, arial, sans-serif]i didn't see any builds of this nature. design[/FONT][FONT=helvetica, arial, sans-serif]ing the steering will be the most challenging as i would have to take it to a fab shop for the welding. i would mount the HT motor normally or take an occ chopper mount and weld it over the rear wheel. i just got this idea but will be a good winter project.i would like to try for a side by side two seater. i am from Portland Oregon and we like to Frankenstein our bikes. here's a pic of the general direction I'm thinking of going
    [/FONT] welded twin bikes.jpg

  2. HeadSmess

    HeadSmess Well-Known Member

    copy the steering pictured... tie rods and ball links. remember to use akermans principle, ie, skew the tie rods out slightly so they form a triangle with the center of the rear axle for best steering control.

    you lose out on a lot of steering geometry using bike headsets... if you could twist the frames by say, 10 degrees, equally but opposite so the headsets, now kingpins, have some tilt, and bend the forks back 7degrees or so, so the wheels have only a small bit of camber... then you got some high speed stability. (0mph+...im going to leave that typo :wacko:)

    simply tilting the frames wont work, cus then the rear wheels are leaning over too, plus the bottom brackets and that sorta stuff becomes a hassle...

    as it is, just wacking two together will be ok for trundling around slowly but dont expect any precision on the steering... two wheels behaves completely differently to four (or 3) and requires geometry to suit...
  3. nishikidrift

    nishikidrift Member

    Thanks you Headsmess for letting my know about Ackermans principle. i learn by doing and some planning will be needed. I will take the next several days a learn about steering and handling.this will be, even after i complete it an on going project and thread ill be able to up date, a big learning curve.:detective::detective:
  4. HeadSmess

    HeadSmess Well-Known Member

    have fun! regulars may notice this is about the first project i havent ranted off about and called silly ;)

    it is silly! but hey, its also fun so yeah...just do it :)

    you dont have to be too flustered over the steering geometry, its not a race car. just the ackermans. amazing the difference that bit makes when WRONG!
  5. nishikidrift

    nishikidrift Member

    ok thank you
  6. nishikidrift

    nishikidrift Member

    My china girl should be here tomorrow. I have decided to go with a jackshaft but that will be a few months before i get it, so i will be getting the bikes seats and steering wheel. I still need to find a go kart steering system. I am thinking in line seating (go-kart seats) would work best and will make it so i can fit in the bike lane properly. For the steering I'm going to use a system off a go-kart, this well determine the width of the cycle.
  7. HeadSmess

    HeadSmess Well-Known Member

    a gokart shop will charge you a fortune. unless you find some 2nd hand for nothing...


    better option.

    there are cheaper, thats just the first one to pop up on a search. weld the LH ones to the tierod, weld a nut on the other end for the RH ones so you can adjust if required. or get LH and RH m8 taps to suit for a real pro look. best way is one rod (a drag link i think its real name is...) from steering shaft to one wheel (line it up IGNORING ackermans, as you want it to steer equally both ways) and one link from wheel to wheel, using ackermans principle, so the wheels turn correctly.
  8. wheelbender6

    wheelbender6 Well-Known Member

    That's a cool idea. I'd like to build a no-welding-required version of it.
  9. nishikidrift

    nishikidrift Member

    Headsmess, Thanks for the search result. my china girl/HT motor came today about noon. the exhaust gasket is useless,paint on them, so ill just make new ones. there is a hole in the intake mount doesn't look to affect the cylinder. but here's the best pic i could get of it. the holes on the right side. I think i will be fine to run but at 18.00 i can just get another jug I'm going to break it in on a beater bike. intake mount hole.jpg
    Last edited: Sep 18, 2015
  10. HeadSmess

    HeadSmess Well-Known Member

    nothing to worry about, just a bit less alloy there and the drill went through.

    not into the cylinder or into the intake port itself, therefore no leak.

    if it was on the exhaust side...it may be a tad weaker but the exhaust needs bracing anyway. dont let them dangle because that is a lot of weight to be hanging in the breeze, vibrating itself to pieces.

    dont worry. therell be plenty of other issues with the HT ;)
  11. nishikidrift

    nishikidrift Member

    You could do it with cross tension members. look at old biplanes and wooden bold to gather planes if you really want to start making one, as they have to be rigid and taught with calculated flex.
  12. HeadSmess

    HeadSmess Well-Known Member

    i have a book with these, um...odd bikes in it.

    ones bamboo, hemp and resin bound joints, and of course...buffalo horns for front forks AND handlebars! awesome :)

    it also has a frame made by getting the required parts of a bike...BB cassette, headset, seat, wheels... bolt em onto a jig in appropriate places... get yourself a spool of carbon fibre, and some resin...

    start stringing the bits together, applying resin as you go. beef up the areas that need it...do what you want elsewhere...

    super light, super strong, and super flexy if you practice or have a natural engineering twist...

    this sort of idea...

    no need for expensive molds...

    or use these?

  13. nishikidrift

    nishikidrift Member

    i have the engine mounted in to a frame for temporary use until i get the twin frames. i have decided to go with the "next avalon" a full suspension frame( i know "next" bikes are not a great brand but this is a budget build.) I am going to use 2 spring loaded chain tensioners to counter the slack issue that will occur, one at the drive sprocket( http://www.ebay.com/itm/49-66-80cc-...chigan-/181196082385?var=&hash=item2a3020ccd1 ) and one at the wheel( http://www.ebay.com/itm/Performance...ngs-/301705757334?hash=item463f108296&vxp=mtr ). this will be a one wheel drive. the other bike in the future might have the electric hub to counter the weight. ill post pictures,possibly video, of the engine in its current frame.
    Last edited: Sep 21, 2015
  14. nishikidrift

    nishikidrift Member

    Update: The carburetor would not tune in so the seller is sending me a new one from china and that will take about 15 days. I found a power wheels in a dumpster and robbed the steering assembly from it I'm either going to use parts from it or I will use it for pointers in building my steering system.
  15. nishikidrift

    nishikidrift Member

    screw getting the engine running I first need to get the cycle made this par of the build is getting put in the shelf, moving on the the actual cycle part of the build is what I' going to focus on.
  16. Marine One

    Marine One Member

    How is the build going? I would Love to see it!