EGIG PERFORMANCE primary gear ratio 27/69 Poligon straight toothed for Vespa Smallframe
Straight-toothed 27/69 primary transmission with poligon connection on the pinion for high-torque Vespa Smallframe setups.
The EGIG PERFORMANCE primary gear ratio 27/69 with a ratio of 2.56 is designed for powerful Vespa Smallframe engines, such as those built with EGIG220 or Quattrini M200. The straight-toothed version uses a Poligon connection on the pinion and can therefore be used for suitable EGIG and Fabbri Poligon crankshafts. The advantage of this design lies in the form-fit power transmission: The torque is not only transmitted selectively via a classic groove or clamping point, but via several contact surfaces of the polygonal contour. This is a decisive factor for a resilient primary drive in motors with high torque.
EGIG PERFORMANCE
27/69
2,56
Poligon
straight splined
EGIG and Fabbri shafts
Check compatibility
What makes the product special
Primary ratio 27/69 with gear ratio 2.56 for powerful Vespa Smallframe engines
Poligon connection on the pinion for positive torque transmission
Can be used with matching EGIG and Fabbri Poligon crankshafts
Suitable for EGIG and Fabbri baskets / repkits, please check other manufacturer combinations
Tested up to 60 hp according to available data
Gear wheel already deburred and ready for assembly
Suitable spacer included to distance the primary to zero between bearing and circlip
Why Poligon?
The Poligon connection on the pinion improves power transmission between the crankshaft and primary drive. Instead of introducing the torque predominantly via a single keyway, a key or a heavily loaded clamping point, the polygonal contour works positively over several surfaces. This distributes the load more widely. In the case of heavily tuned smallframe engines with high torque, this reduces the point load on the connection and provides a technically more robust solution.
For EGIG and Fabbri crankshafts
This Poligon version can be used with matching crankshafts from EGIG and Fabbri. The decisive factor is that the crankshaft has the corresponding Poligon mount. Cone and Poligon systems must not be mixed. Before installation, the crankshaft, pinion mount, gearing and primary cage must clearly match.
Poligon in practice
Positive drive over several contact surfaces
Better load distribution at high torque
Suitable for matching EGIG and Fabbri Poligon crankshafts
Useful for engines such as EGIG220, Quattrini M200 and comparably powerful smallframe setups
27/69 = 2.56 for powerful street and tuning engines
The 27/69 ratio results in a ratio of 2.56 and is therefore a proven basis for high-torque smallframe engines. It is suitable for setups that not only deliver high revs but also usable torque in the mid-range. The final set-up always depends on the cylinder, exhaust, gear connection, tire rolling circumference and intended use.
Fitting to primary baskets and repkits
The EGIG primary gearbox is matched to EGIG and Fabbri baskets and repkits. Many people overlook the fact that the spring pockets of different manufacturers can have different dimensions. If the primary gear, basket and repkit do not fit together properly, play can occur in the repkit. This play is often noticeable as a clacking noise at idle. In the case of combinations with other manufacturers, the fit should therefore be checked carefully before final assembly.
Important compatibility note
Suitable for EGIG and Fabbri baskets / repkits
Other repkits may cause play depending on the spring pocket dimensions
Play in the repkit may be audible as a clacking noise at idle speed
Check spring pockets, basket, repkit and primary gear for clearance-free fit before reassembly
Deburred and with spacer for spacing
The gear is already deburred and prepared for assembly. A suitable spacer is also included in the scope of delivery, which can be used to distance the primary between the bearing and the circlip to zero. Correct spacing is important to ensure that the primary runs smoothly and that there is no unnecessary axial play in the drive.
Available gear ratios
Variants within the series
24/72 = 3.00, straight toothed
27/69 = 2.56, straight toothed
29/68 = 2.35, straight toothed
The variant described here is 27/69 = 2.56
Note on the housing for 29/68
Check the spindle diameter on the pinion
With the 29/68 primary gear ratio, the spindle diameter on the pinion in the original motor housing must be increased by approx. 2 mm. According to the information available, this applies to all manufacturers. For the 27/69 variant described here, the specific housing fit must still be checked before assembly, especially with machined or used engine housings.
Scope of delivery
Scope of delivery according to the information provided
EGIG PERFORMANCE primary transmission 27/69, straight-toothed
Poligon pinion
Primary gear, deburred and prepared for installation
Suitable spacer for spacing to zero between bearing and circlip
Suitable vehicle models
Vespa V50, 50 N, 50 L, 50 R, 50 S, 50 Special and 50 Special Elestart with matching Smallframe engine assembly, matching Poligon crankshaft and corresponding primary basket / repkit.
Vespa 125 Primavera and Vespa 125 Primavera ET3 with matching Smallframe primary drive. Typical applications are powerful conversions such as EGIG220, Quattrini M200 and comparable engines.
Vespa PK50, PK80 and PK125 models with matching smallframe engine, matching Poligon crankshaft, suitable primary basket and sufficiently tested housing fit.
Motovespa Smallframe-related models may be relevant depending on the engine base and primary drive, but must be checked individually. Spanish Motovespa models may differ from Italian Vespa Smallframe models depending on the year of manufacture, market version, engine housing, auxiliary shaft, primary cage and housing clearance.
Brief technical overview
| Manufacturer: egig | EGIG PERFORMANCE |
|---|
| Engine type | Primary transmission |
|---|
| Version | Poligon on pinion |
|---|
| Toothing | Straight toothing |
|---|
| Number of teeth | 27/69 |
|---|
| Gear ratio | 2,56 |
|---|
| Crankshafts | For suitable EGIG and Fabbri Poligon crankshafts |
|---|
| Primary basket / Repkit | Suitable for EGIG and Fabbri baskets / repkits, check other combinations |
|---|
| Load capacity | Tested up to 60 hp according to available data |
|---|
| Preparation | Gear wheel deburred and ready for installation |
|---|
| Spacing | Spacer included for spacing to zero between bearing and circlip |
|---|
| Typical setups | EGIG220, Quattrini M200 and other powerful Vespa smallframe engines |
|---|
| Suitable for | Vespa V50, PV125, ET3, PK50, PK80, PK125 with matching engine setup |
|---|
| Mounting instructions | Check poligon mount, repkit fit, axial play and housing clearance before assembly |
|---|
Conclusion
The EGIG PERFORMANCE primary transmission 27/69 Poligon is a resilient solution for powerful Vespa Smallframe engines where torque, clean power transmission and correct fit in the primary drive are important. The Poligon connection on the pinion is designed for matching EGIG and Fabbri crankshafts, the primary gear harmonizes particularly well with EGIG and Fabbri baskets or repkits. If you have a setup like EGIG220 or Quattrini M200, you get a technically sophisticated 2.56 ratio with a deburred gearwheel and spacer for clean spacing.
FAQ
The Poligon connection transmits the torque positively via several contact surfaces. This distributes the load better than point-loaded connections and makes technical sense for powerful smallframe motors.
Yes, if the crankshaft has the appropriate Poligon mount. The design can be used for suitable EGIG and Fabbri Poligon crankshafts.
The spring pockets from different manufacturers can have different dimensions. If the basket, repkit and primary gear do not fit together properly, play can occur which is noticeable as a clacking noise at idle speed.
The spacer sits between the bearing and the snap ring and is used to distance the primary to zero. This reduces unnecessary axial play in the primary drive.
With the 29/68 variant, the spindle diameter on the pinion in the original housing must be extended by approx. 2 mm. With the 27/69 variant described here, the housing fit should nevertheless always be checked before final assembly.
DE | €
