Jackshaft bb as jackshaft?

Discussion in 'Transmission / Drivetrain' started by jonboy2five, Jun 8, 2008.

  1. jonboy2five

    jonboy2five Member

    what do you all think about using the bottom bracket as a jackshaft? i am planning a 24" bmx bike as a motored toy that doesnt need pedals. running the engine to a larger sprocket on the "drivers side" of the bike then a small sprocket back to the larger toothed freewheel will allow the kind of reduction a chain-driven motor will require. what do you guys think about this?

  2. srdavo

    srdavo Active Member

    cool... it's been done...when I find the thread, I'll post the link.
    what kind of engine are you thinking....?
  3. jonboy2five

    jonboy2five Member


    thank you sr davo i knew it wasnt exactly original, but if its been done before then im not a total idiot... yeah me!
  4. jonboy2five

    jonboy2five Member

    not sure but open 2 suggestions

    like a cy 42/46 cc or a tanaka 47cc...mitsu52cc...active needs a real clutch right?, so probably not. maybe even a 4 stroke if it was small enough, which i doubt.
  5. loquin

    loquin Active Member

    Without peddles, it's not a bicycle, though.
  6. azbill

    azbill Active Member

    zomby uses a bb for his jackshaft mount
  7. loquin

    loquin Active Member

    I know. But...
  8. jonboy2five

    jonboy2five Member

    well thats better..

    hey loquin i am going to keep the pedals now that ive learned the legalities. got a new mitsu 41cc on ebay for $85, got the bike, its going to be a rack mount chain drive at 16.33 : 1...wish me luck:eek:)