Can you change front sprocket in motor?

Discussion in 'Frame Mounted Engines' started by spitball, Jun 1, 2009.

  1. spitball

    spitball New Member

    Hello all,
    I need to lower the gearing on my current configuration (RAW 80cc), the setup I am currently using doesn't seem to have much pick up starting out. I would rather have something easier to cruise at low speed than all out top speed. My question, can the sprocket on the motor be changed to achieve this? I cannot put a larger sprocket on the rear wheel because I am using a King's top hat adaptor for drive sprocket & disc brake rotor & have no clearance to install a larger rear sprocket because it will hit the rear disc caliper.
    Thanks in advance for any help...

  2. srdavo

    srdavo Active Member

    I am not aware of any front sprockets, other than the stock 10 toothers.
  3. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Sick Bike parts has a 9 tooth and 11 tooth for sale

    Use the ratio calculator on the site to figure your speed
  4. Pablo

    Pablo Motored Bikes Sponsor

    These are made for the jackshaft, not the engine output shaft. I read somewhere that someone had found a 9T that fits the engine shaft.
  5. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    thanks Pablo
    I really was not paying attention
    I was wondering about that as it seems there isn't room for an 11 tooth

    What is the shaft diameter for those sprockets?

    My EZ bike kit came with a 9 tooth but it only fits 41 chain which is 1/4 " between the plates
    Last edited: Jun 1, 2009
  6. Pablo

    Pablo Motored Bikes Sponsor

    Ours are 5/8"
  7. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    The EZ bike uses 5/8" too
    I presume the chain size is 415? 3/16" between the plates

    The standard 2 stroke 10 tooth sprocket is badly made
    but the problem is that the keyways are different sizes from
    one engine brand to another and the shafts can be slightlly
    different sizes too

    Believe it or not but the Hoot gearbox comes with a 10 tooth
    sprocket that fits the large keyway on a Grubee 2 stroke
    Last edited: Jun 1, 2009
  8. Pablo

    Pablo Motored Bikes Sponsor

    Our right side sprockets are bike chain size.
  9. lordoflightaz

    lordoflightaz Member

    Could try Grainger

    You would need to know all the specifics. I think best bet would to be to match drive gear, driven gear and chain.