Merkel Motor Wheel?

Discussion in 'Board Trackers and Vintage Motorized Bicycles' started by RocketJ, Jul 5, 2018.

  1. RocketJ

    RocketJ Member

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    I've always been facinated by Joe Merkel's Motor wheel design. I've studied the patents, but it's still difficult to udnerstand how a hub based engine works with a coaster wheel. I found this restoration build, but still no dice. Anyone have an idea? I'd love to give this a try with a more modern engine.

    http://motorenowacja.pl/merkel_motor_wheel/pl
     
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  2. Mr.B.

    Mr.B. Well-Known Member

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    Cool old bike! Thanks for sharing!

    But doing direct drive like that would be a tough nut to crack without a lot of serious design & machining a new rear hub...
    Further complicated that with the long stroke of that old motor it probably has 1/2 the RPM's of a modern one. I just don't see how it could be done without some additional gear reduction somewhere in the drive train.
     
  3. RocketJ

    RocketJ Member

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    You're probably right. I drew up an idea that might work. It's not perfect, but might work. If using a counter clockwise engine, you could mount it to the fender similar to merkels design then build a jack shaft which would attach to the mounting plate under the engine which would then run a chain to the wheel. You could use a centrifugal clutch in order to keep the freewheel function. It's not a complete hub engine, but close.
     
  4. Mr.B.

    Mr.B. Well-Known Member

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    That could work.

    I'm not sure but I think the little Chinese kit 2 strokes engines can be made to run backwards:confused: and they have a cable activated clutch built into their case. Then a fake downward extension of the case could hide the jackshaft & gear reduction...

    Or you could just mount to the right side? Not many would know the difference...
     
  5. Mr.B.

    Mr.B. Well-Known Member

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    I see when you type ( ? ) without spaces you get :confused: in case you where wondering.
     
  6. RocketJ

    RocketJ Member

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    The only feature i like about the china kit is the built in 3d clutch. I wouldn't trust it in reliability for this kind of project though. I've considered putting the engine on the right hand side, but how would you reverse the rotation then? I guess through some sort of jack shaft conversion?
     
  7. Mr.B.

    Mr.B. Well-Known Member

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    I prefer large & vintage 4 strokes myself! LOL!

    I only mentioned the China kit engine because it can be made to run backwards and is narrow.

    With the engine on the right side you could put a centrifugal clutch on the engine shaft and chain to free-wheel cluster on the rear wheel hub (albeit a bit wide). Perhaps the cluster could be adapted to carry a heavier sprocket (like 40 chain?) but still leave a bicycle sized sprocket for the pedal drive. The pedal chainring may also need to be free wheeling ( ?)...
     
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