The CRIMAZ TOP CM5 is a compact five-plate clutch designed for high-performance Vespa Smallframe and Ape 50 engines. It is designed for engine outputs exceeding 30 PS and, despite its extensive friction plate package, requires no spacer plate between the engine casing and the clutch cover.
Five modern friction plates, four hardened steel plates, and two reinforced pressure springs provide a large transferable friction surface and high contact pressure. The polygonal or trilobe connection between the hub and clutch components transmits torque via a positive-lock engagement, thereby reducing the load on the traditional spline connection.
CRIMAZ TOP CM5
5 friction discs
Double spring
over 30 PS
Polygon/trilobe hub
without housing spacer
Important Requirements
The CM5 is not a universal clutch kit that can be combined with all standard components. The following components or characteristics are required for installation and operation:
Use exclusively with the CRIMAZ TOP clutch basket and shock absorber
A clutch cover with a rack-and-pinion reduction is absolutely required
Use a clutch lever on the handlebar with at least 25.00 mm of clearance between the pivot point and the pull nipple
Use mineral gear oil with a viscosity of SAE 30
Five friction discs with a compact profile
The CM5 uses five friction discs, each 2.00 mm thick, and four hardened steel discs, each 1.20 mm thick. The large number of friction surfaces allows for the transmission of high torque without having to excessively increase the spring force alone.
The clutch assembly is designed so that no additional spacer plate is required between the motor housing and the clutch cover. This keeps the motor compact in this area and maintains the position of the clutch cover relative to the stock configuration.
Advantages of the CRIMAZ CM5
For high-performance Vespa Smallframe and Ape 50 engines
Designed for engine outputs exceeding 30 PS
Five friction plates for a large effective friction surface
Four hardened steel discs
Two reinforced pressure springs
Installs on the clutch cover without a spacer plate
Clutch star manufactured from solid material
Polygon/trilobe hub for positive-lock power transmission
Oil-retaining pressure plate with integrated bearing
Retaining ring with anti-rotation feature
Polygonal or trilobe hub connection
The CM5 features a polygonal, trilobe hub connection. CRIMAZ refers to this design as “mozzetto poligonale” or “trilobato.” Unlike a connection that relies solely on a small disc spring, the contours engage over a large surface area with a form-fit.
As a result, the engine torque is transmitted via the flanks of the trilobe connection. The disc spring does not serve as the sole load-bearing element for torque transmission. This reduces localized stress on the shaft and hub, particularly in heavily tuned engines.
Two reinforced compression springs
Two springs with an increased spring rate generate the necessary contact pressure for the five-disc clutch pack. The high spring force prevents the clutch from slipping under high torque, but it also increases the required operating force.
For this reason, CRIMAZ specifies a clutch cover with a rack-and-pinion reduction mechanism. This mechanical reduction reduces the hand force required at the handlebar and enables controlled disengagement of the clutch.
Clutch cover with rack-and-pinion reduction required
A standard clutch cover without additional reduction is not designed for the two reinforced springs. The high operating force would make the clutch lever unnecessarily stiff and place heavy strain on the clutch cable and the operating components.
Use a clutch cover with a rack-and-pinion mechanism
Check the lever travel and ensure the clutch disengages completely
Route the clutch cable neatly and with as large a bend radius as possible
Use a sturdy, smooth-operating clutch cable
Use a compatible clutch lever on the handlebars
In addition to the gear ratio in the clutch cover, the lever geometry on the handlebars must also be correct. CRIMAZ requires a minimum distance of 25.00 mm between the lever pivot point and the cable nipple mount.
A shorter lever arm alters the gear ratio and cable travel. This can cause the lever to feel unnecessarily stiff or prevent the clutch from disengaging cleanly even when the lever is fully pulled. Therefore, the existing clutch lever should be measured before installation.
Technical Specifications
| Manufacturer |
CRIMAZ |
| Series |
TOP CM5 |
| Model |
Five-disc clutch with double spring |
| Friction Discs |
5 pieces, each 2.00 mm thick |
| Steel discs |
4 pieces, hardened, each 1.20 mm thick |
| Compression springs |
2 pieces, reinforced design |
| Hub connection |
polygonal / trilobal |
| Power range |
Designed for engines with more than 30 PS |
| Spacer plate on the clutch cover |
not required |
| Required clutch cover |
Version with rack-and-pinion reduction |
| Required lever geometry |
At least 25.00 mm between the lever pivot point and the pull nipple |
| Recommended oil |
Mineral SAE 30 gear oil |
| Required clutch basket |
CRIMAZ TOP clutch basket with matching shock absorber |
Compatible with Vespa Smallframe and Ape 50
The CRIMAZ CM5 is designed for Vespa Smallframe and Ape 50 engines. Depending on the engine configuration, these include, among others:
Vespa 50 / V50
Vespa 50 Special
Vespa 90 / V90
Vespa Primavera 125 / PV125
Vespa 125 ET3
Vespa PK50 and PK125
Piaggio Ape 50
The key factor is the small-frame clutch assembly used. The CM5 can only be installed with the CRIMAZ TOP clutch basket and shock absorber designed for this purpose.
Oil-retaining pressure plate with bearing
The included pressure plate is designed to collect and distribute transmission oil. The integrated bearing reduces friction between the pressure plate (or actuator) and the rotating clutch.
A sufficient oil supply is particularly important with a compact five-disc package. It aids in cooling the friction plates and reduces wear on the friction and steel discs.
Mineral SAE 30 Oil
CRIMAZ recommends a mineral gear oil with a viscosity grade of SAE 30 for the CM5. The coefficient of friction of a clutch lining depends heavily on the oil used. Unsuitable additives can lead to a slipping clutch or sticking linings.
Do not use untested low-friction or passenger car engine oils
To ensure reliable operation, follow the oil manufacturer’s and viscosity recommendations. In particular, oils containing friction-reducing additives can negatively affect the performance of a wet clutch.
Scope of Delivery
5 friction discs with a modern lining compound, each 2.00 mm thick
4 hardened steel discs, each 1.20 mm thick
2 reinforced compression springs
Solid-material clutch star
Retaining ring with anti-rotation feature
Oil-retaining pressure plate with bearing
Disc spring
Washer
High-strength mounting nut
Not included
CRIMAZ TOP clutch basket
CRIMAZ TOP Shock Absorber or Primary Components
Clutch cover with rack-and-pinion reduction
Clutch lever with a lever travel of at least 25.00 mm
Transmission fluid
Installation Instructions
Install only with CRIMAZ TOP clutch basket and shock absorber
Use a clutch cover with rack-and-pinion reduction
Check the distance between the lever pivot point and the pull nipple: at least 25.00 mm
Coat the friction discs with the specified transmission oil before installation
Install the friction and steel discs in the specified order
Install the retaining ring correctly with the anti-rotation lock
Tighten the high-strength nut to the specified torque
Check the disengagement travel and ensure full free play when the clutch is disengaged
Route the clutch cable with minimal tension and using wide bends
Use SAE 30 mineral gear oil
Conclusion
The CRIMAZ TOP CM5 combines a compact five-disc assembly with two reinforced springs and a form-fit polygon/trilobe hub. It is designed for high-performance Vespa small-frame and Ape engines with more than 30 PS and, despite its large transferable friction area, does not require a spacer plate on the clutch cover.
To ensure a functional and controllable operation, the CRIMAZ TOP clutch basket, the matching shock absorber, a clutch cover with a rack-and-pinion reduction, and the specified lever geometry are absolutely essential.
FAQ
CRIMAZ has designed the CM5 for high-performance small-frame and Ape engines with more than 30 PS. The actual power that can be transmitted also depends on the engine’s characteristics, torque, oil, and the clutch’s adjustment and condition.
No. The CM5 is designed to be so compact that, despite the five-disc pack, no spacer plate is required between the engine housing and the clutch cover.
No. The five-plate clutch may only be used with the CRIMAZ TOP clutch basket designed for this purpose and the matching shock absorber system.
Yes. Due to the high spring force, a clutch cover with a rack-and-pinion reduction is absolutely necessary. A standard cover without a reduction is not designed for this spring configuration.
The distance between the pivot point of the clutch lever and the mounting point of the pull nipple must be at least 25.00 mm. Only with the correct lever geometry will sufficient pull travel and an appropriate gear ratio be available.
The connection features a three-lobed contour, and torque is transmitted via positive engagement along its flanks. As a result, the force is not transmitted solely via a small disc spring.
A mineral gear oil with a viscosity of SAE 30 is recommended. Oils containing unsuitable friction-reducing additives can impair the function of the oil-bath clutch.
No. The CM5 clutch is supplied with a friction plate set, springs, clutch star, pressure plate, and mounting hardware. The CRIMAZ TOP clutch basket and the matching shock absorber must be purchased separately.
Yes. The CM5 is designed for Vespa small-frame and Ape 50 engines. However, for the Ape as well, the CRIMAZ TOP clutch basket, the matching shock absorber, and a suitable clutch actuator must be used.
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