Motorized Next "Revolution" Mountain Bike

Discussion in 'Frame Mounted Engines' started by bmoney, Feb 18, 2012.

  1. bmoney

    bmoney New Member

    Hello fellow mb'ers!!
    Im Brad. I recently started a new build, This will be my second motorized bicycle. The first was a royce union bmx style bike with a daemon 49cc 2 stroke (also my current engine) that I ended up seizing and replacing with a 66cc grubbee gt5 kit.
    Well long story short I ended up selling that bike and had half of the brand new grubbee kit and my old seized daemon kit. So I got a mountain bike for next to nothing and started piecing my kits together.

    Here's what I have so far;
    (Not actual pic)
    26" Next Revolution mountain bike
    -21 speed(currently a 1 speed tho, for now.)
    -All aluminium frame
    -Front suspension
    -V brakes( for now also)

    -49cc daemon 2 stroke (freshly re-built with new cylinder head, piston and rings)
    -cns carburetor
    Sorry crappy pics.
    Well I got it up and running after the re-build and it was running really lean due to the 66cc carb so I brought the needle to the top notch and its was running much better. Still needs a little choke to run perfect but it's pretty good. Also idled first try! But then my chain snapped so I called it a day.
    Last edited: Feb 18, 2012

  2. bmoney

    bmoney New Member

    Today I took a drive down to pirate cycles in north grafton (only like 20 mins from where I live) and picked up a new 415 chain and centrifugal clutch kit.
    Huge thanks to the guys down there, great prices and service! Very friendly people, ill definetly be back soon for more parts!
    Ill be installing the clutch on Monday. Ill try to take lots of pics and maybe do write up. That's all for now! Thanks for viewing!!
    Last edited: Feb 18, 2012
  3. Happy Valley

    Happy Valley Active Member

    Whoa, some big pics, lol.
    Good move on the 49cc anyway, keeps it nice and legal in MA.
    Ride safe, ride responsibly.
  4. bmoney

    bmoney New Member

    Haha yeah sorry about the pic size, uploaded strait from my phone. Ill try to remember to turn down the resolution next time.

    I'm happy with the 49cc.. its plenty fast imo, I really didn't notice any difference from the 66cc. Being leagals always good too haha. Nd of course safety first!!
  5. loquin

    loquin Active Member

    just attach the file url as an upload, instead of using image tags.

    That way, the image is hosted here, so, even if the other site is down for some reason, the picture will still be available here where you're posting about it) and the image showing on the thread is a thumbnail. And, the full size version is there for the viewing, just by clicking the thumb.

    It's available with the advanced posting option, under 'manage attachments.'

    This is the preferred approach for pictures, here.

    See example, below.

    Attached Files:

  6. bmoney

    bmoney New Member

    Ive been busy with work and what not lately, but here's a few updates finally.. I was riding the other day and the drive chain fell off. Come to find out it was because my front engine mount was loose and actually snapped off inside the housing. So i decided since the engine was coming off completely to fix that might as well strip the rest down and get it painted so every things good to go after then and it'll look half way decent.
    Also picked up a port matched intake, hi-flow air filter, and an upgraded hardware kit from pirate cycles,metric tap kit from harbor freight, Woohoo!
    That's it for now!

    Attached Files:

  7. HeadSmess

    HeadSmess Well-Known Member

    be very wary of the alloy frame, and inspect it regularly. like after every hour of riding! hi-frequency vibrations and aluminum do NOT mix!

    looking at your pic, theres a 5mm gap on the front mount. close it up! thats why your stud snapped.

    if clearance is an issue, use a thicker plate, (can be ali for this. its got the thickness to be strong enough.), replace the studs with unbrako bolts (allen key, socket head, whatever) and counterbore so heads dont hit frame.

    clamp the thing down TIGHT! profile the block where it touches the frame so it sits nicely. clamping a flat plate to a thin aluminium frame will only bend the frame, once damaged, the frame is extra dangerous.

    same time, you really need the clamp bit to be made from flat/square bar. cus clamping a round bar at right angles to thin aluminium tubes is just as bad as the plate... you have to think about the area of contact.

    more area, more clamping power before frame distorts.
  8. HeadSmess

    HeadSmess Well-Known Member

    and looking at the rear mount, which hasnt been clearly shown... the block should be on the motor side.

    if clearance is an issue, start thinking about getting someone to weld mounts to the frame.

    all my previous comments about aluminium are repeated. especially once welded, because if it isnt heat treated afterwards, the welds will be the first place to break.

    if you dont know what alloy the bike is exactly(usually a 6061 series or 7005) then welding isnt an option.

    you know that aluminum aeroplanes are held together with RIVETS only, right? no welds allowed on aluminium structural members! same goes for scratches, blemishes/corrosion, or mislocated holes.

    frame failure at 60km/h does hurt, especially in traffic.
  9. bmoney

    bmoney New Member

    Thank you for all the input headsmess. After taking what you said into account and doing a lot more research about ht engines mounted on these over sized aluminum frames i decided i am going to go back to steel instead like my first bike.. I just so happened to pick up a fixie this evening so it looks like my little daemon 49 is going to see its 3rd frame! Ill be making a new build thread for it...
    Thanks for viewing everyone!
  10. HeadSmess

    HeadSmess Well-Known Member

    that first pic..a 24 inch bmx cruiser? that is rad! want want want!

    that would be my first choice for any build :)

    steel is the bomb...and welded mounts on steel...phwoar! ;)

    or brazed/silver soldered if its cromo...

    and just cus i cant help myself...on that first pic you have the tensioner on the top or drive side of the chain...

    always run the tensioner on the bottom, return, or slack side of the chain. then it only has to cope with the clutch starts to stay tight.

    :) weld it on :)
    Last edited: Mar 2, 2012
  11. tooljunkie

    tooljunkie Member

    curve a flat piece of 1/8" x 1 or 1-1/4 into a u.weld bolts or studs to it to replace the u-clamp you are presently wont pinch the frame.over kill would be 2 front and 2 rear.then you would need a taller mounting plate with more holes.
    i was planning on using small muffler clamps,my frame is steel,so i welded.