Aerox Guide: Replacing the secondary gear

Discussion in 'Scooter Guides' started by HasSse666, Feb 4, 2013.

  1. HasSse666

    HasSse666 Member

    Aerox Guide 17: Replacing the secondary gear

    What is what?
    The blue highlighted drives are Primary gears
    The green highlighted drives are Secondary gears

    My Aerox original Gearing consisted of the following :
    Primary Drive: 13/52
    Secondary Drive: 14/43
    This gives a ratio "RF" of 12.3
    (RF = Reduction Factor)

    A lower RF provides a higher gear, but it does not always give a higher top speed,
    because the moped must cope using the heavier gear.
    As always you get to try their way to find the ultimate setup.

    Pic 01
    Malossi-Primary gears 13/44

    Pic 02
    Malossi - secondary gear 14/43

    Pic 03
    Polini - Gearbox Cover

    - You can perform the job with the engine mounted on the scooter.
    - However, you must loosen the center bolt that sits on the rear wheel to release the secondary drive.

    Pic 04
    Unscrew the bolts on the gear cover
    Note that two of the bolts are longer than the other
    - I have emptied the transmission oil in advance

    Pic 05
    Remove the two washers from the small secondary drive
    - The thinner sits at the far end

    Pic 06
    Lift out secondary gear

    Pic 07
    Remove Large Primary and secondary small gears
    These gears are pressed together

    Pic 08
    Clean the gearbox then it's time for the new gears
    Is the engine old, it may be time to replace the bearings also
    Or if you had contaminated transmissionoil

    Pic 09
    Old gears on the left and the new at the right

    Pic 10
    I mount the first primary drive in the new gear cover
    - First heat the bearing to maximum 120 celsius with a heat gun
    - Cool the primary drive with cooling spray (or put it in the freezer overnight)

    Pic 11
    Then you should easily be able to push the axle in place
    Viton seal (gland) was preinstalled on the gear cover

    Pic 12
    Large primary be pressed at Little secondary drive
    I was lazy this time and used a 100-ton hydraulic press ..
    According to Malossis you could do this with the help of a vise ..
    But leave it to a bike shop if you are unsure they might help you

    Pic 13
    Assemble small and large secondary primary gear in the gearbox
    Pic 14
    Now for the Big secondary drive
    Before I presses off the gear, I measure how much end sticks out
    21.6 mm in this case, but the measure of your motorbike for safety's sake

    Pic 15
    Press off large secondary the gear from the shaft
    And then there press the new in place
    According Malossis instruction shall also accomplish this by using a vise ..

    Pic 16
    Fit Large secondary gear

    Pic 17
    Then the two washers

    Pic 18
    Then Polini - gear cover with small primary gear

    Pic 19
    Then you just secure the cover with the bolts

    Pic 20
    Rotate the shafts and listen for abnormal sounds

    Pic 21
    Fill the transmissionoil

    In Swedish ...
  2. emin

    emin New Member

    how do you know what gearing you need and how do you calculate the RF?

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