HF Greyhound in a Tandem

Discussion in '4-Stroke Engines' started by jbcruisin, Jan 9, 2011.

  1. jbcruisin

    jbcruisin Member

    I just started a new build. It's a Worksman Tandem with a 79 cc Harbor Freight Greyhound engine. I will be using an EZ Q matic drive. The bike is new. I bought the bike on Ebay. It had a 3 speed rear. I ordered a single speed coaster brake rear, a front drum brake, a Creative Engineering hub adapter & 62 tooth rear sprocket from Justin at Pirate Cycles. I had it at the weld shop yesterday & he altered the frame to accept an in frame mounted engine. The alterations to the frame cost $105. & he did a great job! More info & pics as I build.

    Here's a link to some pictures:


    Attached Files:

    Last edited by a moderator: Jan 10, 2011

  2. ibdennyak

    ibdennyak Guest

    That's gonna be nice. Curious as to why you eliminated the 3 speed.
  3. jbcruisin

    jbcruisin Member

    I don't pedal, so I don't need 3 speeds. I also figured that when I grease my wheel bearings, a one speed hub will be easier to put together if it comes apart. I ordered a Creative Engineering hub adapter from Pirate so if I ever need another rear hub the one speed will be cheaper to buy and I can use the same hub adapter.Since the 3 speed hub is new, maybe I can sell it & get some of my money back.
  4. jbcruisin

    jbcruisin Member

  5. jbcruisin

    jbcruisin Member

    Did a little more work. Put a NOS Phantom vintage springer on it.

    Attached Files:

  6. Wheres my dog

    Wheres my dog New Member

    Nice work so far sir...

    I always thought of a motorized tandem myself to bring along one of the kids with me!

    Curious to see how the 79cc handles two people plus the weight of the bike and engine itself

    Please keep us informed!
  7. jbcruisin

    jbcruisin Member

    I got some more done to the tandem yesterday. The drive's mounted to the HF engine. It's painted & should be running soon. This is a picture before the drive was on the engine.

  8. jbcruisin

    jbcruisin Member

    Soon it will finally be done. Whizzer air cleaner (originally the idea of the Davis brothers). Carb linkage is finished. Got the exhaust manifold pipe welded to face front so I can route the pipe down around the front.

    Attached Files:

    Last edited: May 23, 2011
  9. RdKryton

    RdKryton Active Member

    Looking good Jay and thanks for the air cleaner props!

  10. rustycase

    rustycase New Member

    Nice MB, JB.

    Lookin at my pile of step-thru frames, the weak point is the front seat down tube, just above where the upper step-thru tube attaches to it.

    Considering you are now powered, I would suggest you do some sort of frame mods in that location to increase the strength a bit. Easier to do now, than after it takes a bend.

  11. jbcruisin

    jbcruisin Member

    front support brace

    Thank yo for the advice. I was thinking about welding a brace across above the top & now I will.
  12. rustycase

    rustycase New Member

    Hi JB,

    I took a pic of a couple frames I could drag out of the pile quickly...
    Hope you are able to see them well enough.

    The bottom frame is a 20yr old 3spd, the middle frame that is completely separated is a Roadmaster, and the top frame is how Univega decided they would deal with the strength issue.

    A step-thru frame is really a handy comfort feature, and I'd be reluctant to forgo it completely... perhaps an additional gusset or brace? and maybe driving an additional seatpost sized tube down inside the seatpost tube as far as it will go??? ..of course, leaving sufficient at the top for normal seat adjustment.
    Then maybe the interior strengthening piece could be pinned???

    Good luck, rc

    Attached Files:

  13. chainmaker

    chainmaker Member

    Pretty Sweet Jay. Looking good. Cant wait to check this bad boy out!
  14. olow

    olow Member

    well i can see ur gonna have 2 have 2 to ride that bad boy
  15. jbcruisin

    jbcruisin Member

    It's finally done!! So far it runs great.

    <a href="http://s472.photobucket.com/albums/rr82/jbcruisin/Tandem/?action=view&amp;current=Tandem016.jpg" target="_blank"><img src="http://i472.photobucket.com/albums/rr82/jbcruisin/Tandem/th_Tandem016.jpg" border="0" alt="Photobucket" ></a>
    Last edited: Jun 19, 2011