About to start a build, quick question

Discussion in 'Motorized Bicycle General Discussion' started by surfishjoe, Oct 14, 2010.

  1. surfishjoe

    surfishjoe New Member

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    Hi all, I am about to start a cruiser build and have been trying research ways to best mount the engines. I think i read something about using a two part epoxy putty to enhance the engine mounts. Any input on this or a link to a thread. I tried searching but no luck. Thanks
     
  2. killercanuck

    killercanuck New Member

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    Hey there, you don't need any epoxies on your mounts. Maybe a little blue loc-tite, or double nuts on your mounts. The one thing you do need to worry about is the size of your front down tube, a fat tube will require a U-bolt type mount, or a 'drill-through'. Drill-through's work, but are discouraged because they can weaken the frame where you drilled it.

    It all depends on your frame's front tube.

    gl.
     
  3. 2door

    2door Moderator
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  4. surfishjoe

    surfishjoe New Member

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    Thanks for the quick responses, should i put rubber or something in between to lesson vibration?
     
  5. killercanuck

    killercanuck New Member

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    Rubber will actually cause more stress on your mounting bolts and cause breakage. The best you can do is make sure your rear mount is flush to the tube, and your front mount is as solid as possible. Have a read through the thread 2Door posted on different techniques if you have an abnormal front tube.

    If it's a fat tube you want is as solid as possible, here's one of my mounts with a normal U-bolt mount, double nutted:
    [​IMG]

    I couldn't bring myself to drilling it :)

    gl.
     
  6. Nougat

    Nougat New Member

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    I made one like that myself with a 4x4x0.25" piece of steel and a muffler clamp, and used nylock nuts on the muffler clamp. Solid as a rock, I couldn't be happier.
     
  7. surfishjoe

    surfishjoe New Member

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    Thanks for the input but the tubes are not oversized. I found what I was looking for in the thread called "vibrations- thoughts and observations. It is under the instructions topic. It says to use an epoxy putty between the mount and the frame for a better fit, less vibrations. What do you guys think of that idea. Getting a list of stuff for the build almost ready to start!
     
  8. Nougat

    Nougat New Member

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    The point of that is to ensure that the rear mount is perfectly flush with the seat tube. If that mount is too tight, file or dremel it to fit. If it's too loose, yes, you can build it up with JB Weld or the like, then file to fit.

    But the aim is a flush fit. If you already have a flush fit, adding epoxy isn't going to help anything, and may make it worse.
     
  9. surfishjoe

    surfishjoe New Member

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    Thanks, sorry for the newbie questions, ill figure it out once i see it on the bike.
     
  10. Nashville Kat

    Nashville Kat Active Member

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    WHY CAN"T THEY RECAST!

    I did my first over a year and a half ago, and still the motor is cast for the ancient heavy tubing- a steel shim inside a larger cast would still EASILY accomodate the older tubes, but make life so much easier for most of us.
    as far as I know, the mototrs are still shipping with the old diameter-

    When I mounted mine- I ground the stupid thing larger, not that difficult but still extra work.

    I got longer studs from the auto store- they still had to be bent out and then back and it still scrtached the frame and creased slightly- but the motor was on with no adapter.

    I still have to mount a 50 when I get back to Florida, and I'll probably just use the oversized u-clamp- but hate the extra weight-
     
  11. msrfan

    msrfan Well-Known Member

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    I made my front mount by bushing down with an aluminum half circle and used the stock clamp with bolts. Came out very clean and tight.

    [​IMG]
     
  12. WildAlaskan

    WildAlaskan New Member

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    u guys totaly hijacked this thread his tubes are fine

    but anyway a little hijacking of my own what if you use a hard rubber hose for a spacer like some industrial stuff
     
  13. msrfan

    msrfan Well-Known Member

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    Sorry for hijacking your thread. Back to your original question. The main problem I ran into is the varying angels of the bike tubing. I personally like to fit the front mount first for looks. No drilling, just good fitting. No rubber, no epoxy, just good metal to metal fitting. Doing it this way usually I find the rear is off a few degrees, but no more than that. If you make a wedge to install at the motor base and then slip the curved mount that your kit came with onto the studs, as you tighten, they will conform to the angel of the seat post and leave no gap. You will have to leave the front loose and kinda cinch both down at the same time as the motor settles into the lowest point. I like to mount the motor as low as possible and keep spacers to a minimum. This method has always worked for me although It takes some time to match the diameters of the mounts with the bike tubing.
     
  14. msrfan

    msrfan Well-Known Member

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    You can also triangulate your install with a head brace. I made this cool bracket for a motor I was having vibration problems with. It went right onto the cylinder studs and reached forward to clamp onto the front tubing. I ended up balancing the motor and not using the clamp, but it's always an option.



    [​IMG]
     
  15. surfishjoe

    surfishjoe New Member

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    Wow thanks for all the responses and suggestions lots of great ideas. I ended up dremeling the front mount a bit and used some rubber to fill the voids in-between. I am going on the old metal to metal contact fitting with some rubber in the voids. This has been a fun build but I think the Spooky Tooth kit is overpriced for what you get. I am about eighty percent done. I am not mechanically inclined- a little bit, getting there.
     

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