2 stroke mount fit

Discussion in 'Frame Mounted Engines' started by PoloMan, Mar 30, 2012.

  1. PoloMan

    PoloMan New Member

    Hello quick question, im starting my second build and about to order a 2 stroke slant head 80cc motor (grubee)

    The bike im gonna use is an old steel diamondback outlook mtn bike with the down tube width of about 1 1/2 inches

    Would i need a universal mount? If so what are my options? Drill? no drill?

    Any suggestions? Thanks

  2. shell shock

    shell shock Member

    no matter what, do not drill your frame! you are asking to shear your down tube
  3. jeffuehrer

    jeffuehrer Member

    Sick bike parts has a decent universal mounting set-up. Steel is the best material and I agree with shell shock too...don't drill the frame.
  4. vermhot

    vermhot Member

    Hey how big of a hole in the frame do you have to have for it to shear the down tube ??!! I drilled a 3/8 hole in 2 different bikes that have alot of miles on and nothing yet !! Is this a urban myth ???!!!! Can you post pics of it ??!!
  5. Al.Fisherman

    Al.Fisherman Active Member

    No it's not a myth. Although you can get away with drilling a hole, here I drilled out the rivet nut that holds on a water bottle, here is the result.
    [​IMG] Steel frame!
    Last edited: Apr 3, 2012
  6. vermhot

    vermhot Member

    Was it just a bad frame to begin with ??!!
  7. vermhot

    vermhot Member

    Were you riding it when it cracked ??!!
  8. jeffuehrer

    jeffuehrer Member

    Cracks kill.
  9. Al.Fisherman

    Al.Fisherman Active Member

    The frame was fine, I drilled out the rivet nut that holds the water bottle bracket, to run wire up to the top. YES my son was riding it, but thankfully he was riding it slow in a parking lot when the tube snapped. That is why I don't recommend drilling into a standard tube.
  10. vermhot

    vermhot Member

    Wow I would have never thought that would happen !!!!
  11. Al.Fisherman

    Al.Fisherman Active Member

    Reread post #8
    Time to rethought :>)
  12. vermhot

    vermhot Member

    Wait till you see the big hole that I drilled in mine !!!!!!! Will make most cringe!!!
  13. Al.Fisherman

    Al.Fisherman Active Member

    No it won't...why...I'm not gonna be riding it. Time to rethink.
  14. HeadSmess

    HeadSmess Well-Known Member

    i got a reputation as a kid for breaking BMX frames... and not always cheap ones, either...

    metallurgy is a strange beast. when combined with stress raisers and vibrations, its gets even wackier...

    DONT DRILL HOLES! and check all joints on a motorised frame weekly, regardless!