Clutch sprocket -FA ITALIA- Vespa Cosa2, PX (1995-) – (for 67/68 tooth primary gear, helical) – 20 tooth

Together with the large primary wheel, the clutch pinion forms the so-called primary reduction. Here, the transmission ratio can be changed by simply replacing the clutch pinion.
Those who cannot manage this can also replace the primary wheel.
For the latter option, however, the engine must be opened completely, for the clutch pinion, however, it is sufficient to remove the clutch cover together with the clutch.
There are three primary wheels that were originally installed.
65 teeth: PX200, Rally200
67 teeth: Sprint Veloce, Super, GT, GTR, TS
68 teeth: PX80, PX125, PX150, all Cosa models.
The fewer teeth the primary gear has, the longer the possible reduction.
The fewer teeth the clutch pinion has, the shorter the possible reduction.
The following combination can be used:
65Z = 23Z
67/68Z = 20Z, 21Z, 22Z
There are now (from z.The PX80 and PX125 models originally have a primary gear with 68 teeth and a coupling pinion with only 20 teeth. Here, the 22 tooth sprocket can be installed without any further adjustments and the transmission ratio can therefore be extended considerably (+ ~10km/h). Ideal for PX80 which are converted to 125/135cc or PX125 which are converted to 166/177cc. If this is still too short, the BGM special pinion with 23Z can be used for the 67/68Z primary gear.
As lubricant we recommend the BGM Pro Street gear oil (BGM2025, corresponds to specification API GL-3).
AI-translation