Discussion in '2-Stroke Engines' started by aranor104, Jul 18, 2014.

  1. aranor104

    aranor104 New Member

    CAn anyone give me a link on ebay to a good rubber that will reduce the vibration of the engine.

  2. HeadSmess

    HeadSmess Well-Known Member

    before anyone tells you to use the search function, or tells you to save your money, im going to!

    it doesnt reduce vibration, it INCREASES it. rather than constraining the engine, its allowed to flop around wherever it wants to go...bad idea!

    mount the engine as solidly to the frame as possible. if they had 3 mounts, ok, id advise differently, but with need them TIGHT and SOLID.

    welding, or brazing the mounts on so one bolts the engine in tight, and no longer resorts to bolt tension to hold it in place by "squeezing" the frame, reduces vibration to virtually NIL.

    by the time you tighten the clamps up enough to hold the engine steady against the chain tension when in use, the rubber has all but been squished solid anyways. defeats the whole purpose. thats why 3 mounts is ok for rubber. triangles are very stable.the bolts can be loose in the rubber, and then vibration is absorbed.

    a bird sitting on a wire has to dig its claws in to stay "up". a bat just dangles. the engine on your bike has to dig ITS claws in to stay "up", also.

    (hmmm, im gunna have a go one day of sticking me engine in upside down!)

    larger frames absorb more buzz too. a stiff bmx frame is just that, stiff. a 24" frame MTB has lots of "absorption" qualities. a 24" MTB frame is also pretty BIG! (18" is sort of standard) this is the seat tube measurement, not the wheel diameter, be aware ;)

    whatevers left can be eliminated by using those big fat squishy handgrips, etc etc.

    my roadbike sends my fingers numb after ten minutes, whereas i can ride the pushy for hours, no hassles. its the potholes and catseyes that hurt!

    bob weights in the handlebars will also reduce any high frequency "buzz".
  3. HeadSmess

    HeadSmess Well-Known Member

    wow. i just managed to find the similarity between a bird on a wire and a motorised bike...

  4. aranor104

    aranor104 New Member

  5. Fabian

    Fabian Well-Known Member

    :iagree: the only modification i make is to apply about 10 layers of duct tape to the frame when mounting the engine to stop vibration abrasion between the engine mount and the bicycle frame.

    The reason why you need to solidly mount the engine to the frame, and the reason why rubberised mounts don't work on a motorised bicycle is because the engine and frame are approximately the same weight; with the frame not having enough weight to resist the oscillation of the engine.
    Rubberised engine mounts work on cars and motorbikes because the frame/chassis (due to is higher weight) is able to resist the motion of the engine, forcing the engine mounts to absorb vibration energy.


  6. HeadSmess

    HeadSmess Well-Known Member

  7. HeadSmess

    HeadSmess Well-Known Member


    very true, and you need more mounting points than just two! i have never, ever come across an engine AND gearbox combination that only uses two mounts.

    sure, most engines only have two mounts...and some gearboxes only one! but when theyre bolted up rigidly together like they do... 2+1= 3 :)

    too many mounts also defeats the whole purpose.