rubber motor mounts

Discussion in 'Frame Mounted Engines' started by superhawk, Oct 19, 2008.

  1. superhawk

    superhawk New Member

    I've already posted this on another site, but maybe some members here will be interested.....
    -Just got one of China 66cc motors and looking at the flimsy stock mounts, I decided to make them better. At the same time, make them rubber mounted and adjustable side to side.
    This is what I came up with for now, I would've made the mounts out of aluminum but steel is more forgiving in the first design, besides my aluminum TIG welding sucks.
    The rubber inserts are front sway bar link rubbers from a 5litre Mustang turned down to fit. They are made of polyurethane which are quite hard.I may use a softer rubber later.The feel gauge(0.004) in one of the pics. is the clearance so the motor can move up + down but not twist from side to side. The weak spot is the stock 6mm threaded mounting holes on the motor, if they strip out I'll helicoil them as there doesn't seem to be enough meat for 8mm maybe 7mm.Hopefully this design won't throw the drive chain, then a head steady will be necessary.
    My rubber mount design is a flagrant copy of the ones on the Norton Commando motorcycle, so feel free to use any and all of these ideas. I have yet to make the front frame clamp/mount. By the way, that's a Creative Engineering & Design clutch housing, real slick

    Attached Files:

    Last edited: Oct 19, 2008
    Fabian likes this.

  2. grezm0nkey

    grezm0nkey Member

    nice...i like...i dont have one of those motors and dont know how much vibration u get from it, but love to hear what u have to say after its all done and said. please keep us informed. i will have to keep this mod in mind.

    cheers, grez
  3. superhawk

    superhawk New Member

    I finished the front motor mount today, I think I overbuilt the whole system, I probably could mount a small block Chevy in the bicycle.
    I hope this works, spent way too much time on this project.

    Attached Files:

  4. fetor56

    fetor56 Guest

    Professional looking job u did there man.
  5. mclark999

    mclark999 New Member

    How much vibration did it cut out? I'd like to do something like this but it has to be something I can bolt together. I don't have a welder.
  6. Fabian

    Fabian Well-Known Member

    :iagree: a brilliantly presented design and highly desirable if the metalic parts of the rubber mounting system could be powder coated red or maybe orange.
    Even if it proves not to be as effective as the concept might suggest, the aesthetics of the design make it a "must have" item.

    Can the design be adapted (and made to work correctly) for the Sick Bike Parts shift kit?
  7. IbedaYank

    IbedaYank Member

    be interesting to see how solid the motor is and if there is any give and how long it will take before it starts to be give and it starts to throw chains
  8. Big Red

    Big Red Active Member

    I still think any rubber between the frame and motor will increase vibration, BUT you did a very PRO job on it. ya gotta let us know how it works out for you.
    Big Red.
  9. professor

    professor Active Member

    This, OP was done years ago, but I can tell you if you make rubber mounting that retains the engine in every direction, rubber mounts work.
    I can't think of a car that lacks rubber engine mounts. Harley went to them long ago.
    Ford began rubber isolation in their model yr. 1932.
    I used isolators on my HF 212 to make it tolerable.
    I have 4 on the bottom of the engine and one on each side of the top.

    Normally, a tiny 66cc would not make much vibration, but apparently these China kits are so badly balanced that they rattle.
    The exhaust on the China kit would need to be tied strongly to the engine rather than to the frame or a slip joint fabricated with springs, or any vibes would probably fatigue it to breakage.
  10. HeadSmess

    HeadSmess Well-Known Member

    beautiful work :)

    everyone has their two cents worth.

    3 points of suspension, rather than two. triangulate!

    either two rubbers on one end, or a head brace.

    thats the issue in my mind. all good mounts use three points to stop movement in both axes...

    *talks but is too lazy to make one*
  11. Big Red

    Big Red Active Member

    I agree about the three point hookup, even HARLEY has more than two points.
    And yeah, Didn't look at the date. I've done that before.
  12. HeadSmess

    HeadSmess Well-Known Member

    if jesus could be resurrected, so can this thread!
  13. imraanc

    imraanc New Member


    how can i buy these mount adpters and from where and which country is this for sale in?
  14. mclark999

    mclark999 New Member

    Sway bar mounts

    I used polyurethane sway bar mounts. I bought the correct diameter for the down tube and seat tube and then cut and drilled a plate to mount the motor to.

    The mounts do reduce vibration immensely, especially the thicker mount on the seat tube. I feel no vibration through the seat, but some at the handlebars.

    P1060311.jpg P1060313.jpg P1060309.jpg P1060310.jpg

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