Project 79cc predator build bmx

Discussion in 'Photos & Bicycle Builds' started by Imthegrt1, Sep 29, 2014.

  1. Imthegrt1

    Imthegrt1 Member

    Hello all this is my first build and I welcome all feed back.
    i wanted to build a box bike with something different.
    so here goes.
    I have decided to use a mongoose frame it had the best angles for the build.
     

  2. dirtwarrior

    dirtwarrior Member

    I am near you and can lend a hand. I am doing a friction drive on my trike.
     
  3. Imthegrt1

    Imthegrt1 Member

    So the predator motor has a different shape than ur std motor and I think will work great for the bmx build
     

    Attached Files:

  4. Imthegrt1

    Imthegrt1 Member

    So took off tank and muffler freed up alittle of room will still have to cut into frame motor is going be located in the center and custom tank will be made for top and no kit bike tank!
     

    Attached Files:

  5. Imthegrt1

    Imthegrt1 Member

    So after going threw about 100 bikes in the garage the mongoose has the best angle setup for the right shape.
    So first cut made on the frame to make room for the motor
     

    Attached Files:

  6. Imthegrt1

    Imthegrt1 Member

    So got some metal.
    here is the mock up for the frame and motor going be perfect fit
     

    Attached Files:

  7. KCvale

    KCvale Motorized Bicycle Vendor

    Ummm... Why are you using a round pipe for the motor mount base?
    Don't you think a flat plate to rest the motor on would be better?
     
  8. KCvale

    KCvale Motorized Bicycle Vendor

    You also know you can't just put a sprocket on that engine and direct drive your back wheel right?
    You need a transfer case for the clutch and gear reduction to final drive sprocket.

    Q-matic makes one modified to fit the 79 Pred bolt pattern for $300 and they work well.

    [​IMG]

    Here is a really good shot of what is required to fit that beast in a bike, and that big 29" Macargi Fatal Love bike.

    [​IMG]

    Are you still sure what to try put all 70+ pounds of that in a hacked up small kids bike?
     
  9. Imthegrt1

    Imthegrt1 Member

    Good info. Thanks for the input
    The motor is actually going be bolted to a plate which is bolted to the bottom pipe.
    Seen that setup for predator in your picture before.
    Going have a clutch and jack shaft on this bike .
    Got a few 24 and 26 bikes I plan to build later like that .
    my thing was just wanted to build a 20 bmx bike that wasn't useing a china motor.went with the mongoose frame because I wanted to use a good bike that was built alittle stronger than the walmart ones. this frame is from the 90's
     
  10. Imthegrt1

    Imthegrt1 Member

    Started welding on the frame. I'm by far not a good welder but did the hammer test and it's sold spot weld
     

    Attached Files:

  11. Imthegrt1

    Imthegrt1 Member

    So welded and grind and welded some more .put on some plates welded and grind some more.i know not the prettiest but isn't going to move.
     

    Attached Files:

  12. butre

    butre Well-Known Member

    that looks pretty burnt, are you torch welding? most people like to use mig welding for bicycle frames
     
  13. wheelbender6

    wheelbender6 Well-Known Member

    It will take some huevos grandes to ride that BMX when you finish the install.
     
  14. Imthegrt1

    Imthegrt1 Member

    No just old school stick welding
    6013 rods at 60 amps
     
  15. Imthegrt1

    Imthegrt1 Member

    Did some more grinding and welding and grinding today
    Motor fits in tight.
     

    Attached Files:

  16. Imthegrt1

    Imthegrt1 Member

    Now time to start to order some parts gears and sprockets and build the jack shaft
     

    Attached Files:

  17. KCvale

    KCvale Motorized Bicycle Vendor

    (just scratches head...)
    Sorry, for the life of me I simply can't understand why you would purposely put a round pipe where a flat plate or at least a square pipe or channel metal should be for a stable engine mount.

    Are you at least going to use muffler clamps to hold your plate for some sort of flat area and full tube grip?
     
  18. Zoombike

    Zoombike New Member

     
  19. Imthegrt1

    Imthegrt1 Member

    I used the pipe cause it was 2 inch same as the frame.
    Ill attache angle arm each side for motor mount or box tube to the bottom pipe.
    Also there is a side mount on front tube and a back mount going on back tube will be install.
    But your right square tube for bottom would just been easier!
     
    Last edited: Oct 3, 2014
  20. Zoombike

    Zoombike New Member


    and weaker
     
Loading...