Aerox Guide: Replacing the secondary gear

HasSse666 · Feb 4, 2013

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

Note
- 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
Note
- I have emptied the transmission oil in advance

Pic 05
Remove the two washers from the small secondary drive
Note
- 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
Note
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
Note
- 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
Note
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 ..
Note
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
Note
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
Note
According Malossis instruction shall also accomplish this by using a vise ..
DO NOT FORGET TO MEASURE HOW MUCH IT`S STICKS OUT!

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 ...