Rotary power assisted bike's

Discussion in 'General Questions' started by BikeMan, Feb 23, 2009.

  1. BikeMan

    BikeMan Member

    Attached Files:

  2. heathyoung

    heathyoung Member

    German design, sachs rotary IIRC.
  3. mabman

    mabman Member

    Yup, the Chopper From ****, the only motor assist bike to ever grace the pages of Easy Rider magazine uses a Sachs one for power. Go to: and go to the Gallery and hit the history button. Numbers 18 and 25 (Easy Rider shot) are the CFH.

    Number 13 is myself on the left looking over my first 4 stroke endeavour in 2001. Ryobi weedwhacker engine.
    Last edited: Feb 23, 2009
  4. LesIzzMoore

    LesIzzMoore New Member

    I like the lower center of gravity too.

    Some immediate drawbacks:
    * $1,550!
    * 2 stroke = dirty
    * 18 lbs!!
    * You need to use their wheel rather than your own. Durability? Weight? Gearing? Brakes?

    This design was originally made by Sachs, but I apparently they sold off this particular division several years ago and the current iteration is made in Taiwan to the same or similar specs. This would suggest that the design is relatively proven, and probably reliable.

    One nice feature is electric start. Which would make it (conceivably) easy to use the assist only on uphill sections instead of having to leave it idling for most of a ride.
    Last edited: Feb 23, 2009
  5. Accender

    Accender Member

    The low center of gravity should offset the weight x2.
    Hub drive is durable.

  6. JemmaUK

    JemmaUK Guest

    The sachs engine is a modern type 2-stroke - as such it is not dirty in comparison to some of the other older designs. Probably the worst in that department is the 18cc semi-diesel hilfsmotor kit sold in germany under the Lohmann name. The fuel for that is somewhat esoteric - consisting of petrol/parafin & lubrication oil mixed together... the engine uses variable compression and an air valve to provide throttle response. They are sometimes available on Ebay germany - but if you get one be very very sure you get a complete one.

    Jemma xx