Will this mount fail?

Discussion in 'Mounting Techniques for Bicycle Motors' started by mjharden1, May 25, 2011.

  1. mjharden1

    mjharden1 New Member

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    Hi, I have an oversized mount on the engine. The mounts are wide enough, but the curve does not match with the tube. Therefore it would have a large gap.

    I took and shaped the thick rubber from a grip I had.

    My question

    1) will this fail, strength and vibration.

    2) The original mount studs were too short. So I replaced with longer bolts. since I tighten into the engine mount holes, I am a bit worried the mount strength is more dependent on the engine mount thread, is this valid?

    Not riding. Want to be certain I can trust this mount. Thanks
     

    Attached Files:

  2. BarelyAWake

    BarelyAWake New Member

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    Were it my bike, I'd be strongly temped to use a 1/2 round coarse file and/or a dowel w/80gt sandpaper (best yet a Dremel w/a sanding drum) and increase the recessed curve of the motor mount to fit the bike's down tube... it's close so I doubt you'd have much difficulty.

    The awesome thing is you've got room, the stud spacing is wide enough & the metal (steel) clamp will take the bend w/ease.
     
  3. Al.Fisherman

    Al.Fisherman New Member

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    Welcome...
    Will it fail, yes most definitely. If it doesn't I'd really be surprised. Since you are working on a oval tube and not a round tube, If it was my bike I'd remove the engine and wrap a sheet of course sandpaper to the area that the mount will be. Sand the engine mount to form the tube. Another option would be to customize the front mount. My LAST choice would be to shim it, but it looks like there is way to much to shim.

    Engine Mounting pictures by Ron-Becker - Photobucket

    Homemade Mods pictures by Ron-Becker - Photobucket

    If not, this is what you are looking down the road.....
    Broken mount repair pictures by Ron-Becker - Photobucket
     
  4. jototojo

    jototojo New Member

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    Hello, i have kind of the same problem, but the curved part of the one that grabs the frame doesnt fit and i've been riding my bike for 1 year and a half and nothing happened.
    I didnt do anything about it and yours look better than me so dont do anything, just leave it like that.
     
  5. Al.Fisherman

    Al.Fisherman New Member

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    Sure glad I didn't ask you for advise. You just might be lucky (actually I don't believe in luck) If you're going to do something why not right now then over again later. I wouldn't ever think about installing a engine that far out of alignment, . Besides vendors sell adapters (not the ones you drill through the frame) that will work.
     

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