The new reinforced axle shaft for Vespa smallframe engines is
made of high-strength steel with a corresponding vacuum carburizing
treatment.

The material used and the new sizing make the shaft
particularly suitable for tuned engines or with displacements greater
than normal (even up to 250 ccm)

Today, thanks to recent investments by some manufacturers, it is
possible to find on the market a wide range of  very powerful thermal groups
that even exceed 40 horsepower.

I remind you that the Vespa smallframe engine was designed to last over
time and its power hardly exceeded 10 horsepower.

With these power increases, it is essential to adjust all mechanisms to avoid breakages and premature wear.

Example of the new sizing. The threading has also been increased to M16x1.25

Indicative photo

This article is provided assembled with all the parts included in the presentation photo.

4-speed gearbox completely made from solid steel for high-quality carburizing and tempering.


All parts are designed in an assembly studio with a 3D CAD drawing program and made by the best mechanical workshops in the Modenese area.


Three configurations have been studied suitable for all engines and all uses of your smallframe Vespa.

Indicative photo

This article is provided assembled with all the details included in the presentation photo.
4-speed gearbox completely made from solid steel for high-quality carburizing and hardening.
All parts are designed in assembly studio with a 3D CAD drawing program and made by the best mechanical workshops in the Modenese area.
Three configurations have been studied suitable for all engines and all uses of your Vespa smallframe.

Indicative photo.

Engages with original crowns

Warning: Compatible only with flat shift lever

Warning: Compatible only with flat cruise control

Warning: Compatible only with flat shift lever

Warning: Compatible only with flat cruise control

Warning: Compatible only with flat paddle shifter

This article is provided assembled with all the details included in the presentation photo.

4-speed gearbox completely made from solid steel for high-quality cementation and hardening.


All parts are designed in assembly studio with a 3D cad drawing program and made by the best mechanical workshops in the Modenese area.


Three configurations have been studied suitable for all engines and all uses of your Vespa smallframe.

This article is provided assembled with all the details included in the presentation photo.

4-speed gearbox completely machined from solid steel for high-quality carburizing and hardening.


All parts are designed in an assembly studio with a 3D CAD drawing program and made by the best mechanical workshops in the Modena area.


Three configurations have been studied suitable for all engines and all uses of your Vespa smallframe.

This article is provided assembled with all the details included in the presentation photo.
4-speed gearbox completely made from solid steel for high-quality carburizing and hardening.
All parts are designed in an assembly studio with a 3D CAD drawing program and made by the best mechanical workshops in the Modenese area.
Three configurations have been studied suitable for all engines and all uses of your smallframe Vespa.

Gear with z18 Crimaz

The secondary crowns for Vespa smallframe and Ape 50 allow to
reduce the spacing of your gearbox, improving the engine performance.
The engagement slots have been enlarged for faster and more precise shifting.
Particular heat-treated, micro shot-peened, and ground.
For correct gearbox assembly, it is recommended to keep a clearance
maximum of 0.1 mm and to follow the reference mark indication
(wheel side)

Gear with z16 Crimaz

The secondary crowns for Vespa smallframe and Ape 50 allow to
reduce the spacing of your gearbox, improving the engine performance.
The engagement slots have been enlarged for faster and more precise shifting.
Particular thermally treated, micro-shot peened and ground.
For correct gearbox assembly, it is recommended to keep a play
of a maximum of 0.1 mm and to follow the reference mark indication
(wheel side)

Engage with z21 Crimaz and z22

The secondary crowns for Vespa smallframe and Ape 50 allow you to
reduce the spacing of your gearbox, improving engine performance.
The engagement slots have been enlarged for a quicker and more precise shift.
Particular heat-treated, micro-peened, and ground.
For the correct assembly of the gearbox, it is recommended to maintain a play
of a maximum of 0.1 mm and to follow the reference mark indication
(wheel side)

Engage with z17 Crimaz and z18

The secondary crowns for smallframe Vespa and Ape 50 allow you to
reduce the spacing of your gearbox, improving engine performance.
The engagement slots have been enlarged for a faster and more precise gear change.
Heat-treated, micro-peened, and ground part.
For the correct assembly of the gearbox, it is recommended to maintain a play
of a maximum of 0.1 mm and to follow the reference mark indication
(wheel side).

Engage with z13 Crimaz and z14

The secondary crowns for Vespa smallframe and Ape 50 allow to
reduce the spacing of your gearbox, improving engine performance.
The engagement slots have been enlarged for faster and more precise shifting.
Particularly heat treated, micro shot peened and ground.
For correct gearbox assembly, it is recommended to maintain a play
of a maximum of 0.1 mm and to follow the reference mark
(wheel side)

Engage with z10

The secondary crowns for Vespa smallframe and Ape 50 allow
to reduce the spacing of your gearbox improving engine performance.
The engagement slots have been enlarged for a quicker and more precise gear shift.
Particularly heat-treated, micro shot-peened, and ground.
For correct gearbox assembly, it is recommended to maintain a maximum play
of 0.1 mm and to follow the reference mark indication
(wheel side)

The new reinforced rotating axle for Vespa smallframe engines is
made of ultra-high strength steel with vacuum carburizing treatment.

The material used and the new sizing make the shaft
particularly suitable for tuned engines or those with displacements
above the norm (even up to 250 ccm)

Today, thanks to recent investments by some manufacturers, it is
possible to find a wide selection of very powerful thermal units on the market
that even exceed 40 horsepower.

Remember that the Vespa smallframe engine was designed to last over
time and its power rarely exceeded 10 horsepower.

With these power increases, it is essential to adjust all the mechanisms to avoid breakages and premature wear.

Example of the new sizing. The threading has also been increased to M16x1.25

CLUSTER THIRD AND FOURTH SHORT
z10-14-17-20
Compatible with:
z58-54-50-46 = Orig.

Integral detail. The gears are not interference-fitted onto the central body
Compatible with Vespa/Ape50 Piaggio and aftermarket engine casings.

The smaller gap in the third and fourth gear shift allows the engine
to stay in torque, reaching maximum speed in less time.

Supplied with M10x1 nut and reinforced washer.

The engagement slots have been revised to make shifting quick and precise.

Additional oil passages can be seen on the internal diameter for
oil flow, chamfers for the insertion of the cruciform, and
a reference notch (wheel side) for correct gearbox assembly.

It is recommended to maintain a maximum play (during assembly) of 0.10mm on the crown gear set, shims, and circlips.

CLUSTER FOURTH SHORT
z10-14-18-21
Compatible with:
z58-54-50-46 = Original

Integral detail. The gears are not mounted by interference on the central body
Compatible with Vespa/ape50 Piaggio and aftermarket engine casings.

The smaller jump in shifting from third to fourth gear allows the engine
to stay in torque, reaching maximum speed in less time.

Supplied with M10x1 nut and reinforced washer.

The construction of the teeth is carried out with a module gear shaper tool
1.5 with relative corrections for the sprockets added to the original
pair.

The tooth width has been widened (1 mm towards the inside) to
achieve greater resistance without compromising smoothness.
The spring seats have been revised to use springs with square wire. The greater travel of the damper preserves the gearbox and cruise.
In the center, there is a roller bearing on the most
stressed part and a guide bushing on the shaft. This solution
allows the bell to be compatible with the original starting
gears.

The construction of the teeth is carried out with a module gear hob
1.5 with relative corrections for the pinions added to the original
pair.

The width of the tooth has been widened (1 mm towards the inside) to
achieve greater resistance without compromising smoothness.
The spring seats have been revised to use springs with square wire. The greater travel of the shock absorber preserves the gearbox and the cruise.
In the center, there is a roller bearing on the most
stressed part and a guiding bushing on the tail. This solution
allows the bell to be compatible with the original starting gears.

The construction of the teeth is carried out with a module hob
1.5 with relative corrections for the pinions added to the original
pair.

The width of the tooth has been widened (1 mm towards the inside) to
have greater resistance without compromising smoothness.
The spring seats have been revised to use springs with square wire. The greater travel of the shock absorber protects the gearbox and cruise.
In the center there is a roller bearing on the most
stressed part and a guide bushing on the shaft. This solution
allows the bell to be compatible with the original starting
gears.

The construction of the teeth is carried out with a module gear shaper
1.5 with relative corrections for the pinions added to the original
pair.

The width of the tooth has been widened (1 mm inward) to
provide greater strength without compromising smoothness.
The spring seats have been revised to use springs with square
wire. The greater travel of the shock absorber preserves the gearbox and clutch.
In the center, there is a roller bearing on the most
stressed part and a guide bushing on the shaft. This solution
allows the bell to be compatible with the original starting
gears.

The construction of the teeth is carried out with a module 1.5 gear shaper tool with relative corrections for the pinions added to the original pair.

The width of the tooth has been widened (1 mm inward) to have greater resistance without compromising smoothness. The spring seats have been revised to use springs with square wire. The greater stroke of the shock absorber preserves the gearbox and the cruise. In the center, there is a roller bearing on the most stressed part and a guide bushing on the shaft. This solution allows the bell to be compatible with the original starting gears.

The construction of the teeth is carried out with a module
1.5 gear shaper tool with relative corrections for the pinions added to the original pair.

The width of the tooth has been widened (1 mm towards the inside) to
provide greater resistance without compromising smoothness.
The spring seats have been revised to use springs with square wire. The greater stroke of the shock absorber preserves the gearbox and cruise.
In the center, there is a roller bearing on the most
stressed part and a guide bushing on the shaft. This solution
allows the bell to be compatible with the original starting gears.

The construction of the teeth is carried out with a module 1.5 gear cutter tool with relative corrections for the pinions added to the original pair.

The width of the tooth has been widened (1 mm towards the inside) to have greater resistance without compromising smoothness.
The spring seats have been revised to use springs with square wire. The greater stroke of the damper preserves the gearbox and the driveshaft.
In the center, there is a roller bearing on the most stressed part and a guide bushing on the shaft. This solution allows the bell to be compatible with the original starter gears.

Provided are no. 3 M4 screws with a recessed hexagon and a central screw with a hexagonal head no. 13

Required wrench: 19

Equipped with a self-locking cone capable of stably coupling the crankshaft and pinion.

With this system, the key does not need to be used. Ideal
for modified engines and for crankshafts damaged on the key
seat.

The cone is compatible with the entire range of Piaggio crankshafts
and interchangeable. It is recommended to apply strong type lock
on the fixing nut and to respect the tightening torque of 60-70 Nm.

For disassembly, a 3-thread puller is required, not included.

Equipped with a self-locking cone capable of stably coupling the crankshaft and pinion.

With this system, the key does not need to be used. Ideal
for modified engines and for crankshafts damaged on the
key seat.

The cone is compatible with the entire range of Piaggio
crankshafts and interchangeable.  It is recommended to apply a strong type of locking agent on the
fixing nut and to respect the tightening torque of 60-70 Nm.

For disassembly, a 3-thread puller is required, not included.

Equipped with a self-locking cone capable of stably coupling the crankshaft and pinion.

With this system, the key does not need to be used. Ideal
for modified engines and
for crankshafts damaged at the key seat.

The cone is compatible with the entire range of Piaggio crankshafts
and interchangeable. It is recommended to apply strong-type locking compound on
the fastening nut and to respect the tightening torque of 60-70 Nm.

A 3-thread puller, not included, is required for disassembly.

Equipped with a self-locking cone capable of stably coupling the crankshaft and pinion.

With this system, the key does not need to be used. Ideal
for modified engines and for crankshafts damaged at the key seat.

The cone is compatible with the entire range of Piaggio crankshafts
and interchangeable. It is recommended to apply strong-type locking compound on
the fixing nut and to respect the tightening torque of 60-70 Nm.

For disassembly, a 3-thread extractor is necessary, not included.