The Stingworks Sei Giorni GP Clutch is the original choice when it comes to modern clutches for Vespa Wideframe and early Largeframe engines with a flat clutch. We supply the original Stingworks clutch: a modern, fully assembled solution for classic Vespa engines that combines stock-like installation with significantly higher load capacity. The original clutch cover remains in place; no modification of the cover or engine casing is necessary.
Original Stingworks
Sei Giorni GP
6 plates
23T BGM PRO Custom Solution
up to over 30 PS / 25 Nm
Modern clutch for older Vespa engines
The Stingworks Sei Giorni GP brings modern clutch technology to vehicle groups for which there are few reliable solutions: Vespa Wideframe models from around 1953 onward, early Largeframe models such as the VNA, VBA, VNB, VGLA, and VBB1T, as well as compatible Motovespa 125S and 125N engines with flat clutches. This makes it suitable for original engine overhauls, meticulous restorations, touring-ready engines, and high-performance builds based on classic designs.
The main advantages
Original Stingworks Sei Giorni GP clutch
Plug-and-play installation without modifications to the engine casing
Original clutch cover can still be used
Lightweight and smooth to operate despite high load capacity
6 discs with modern KTM clutch lining technology
Reinforced hub construction for high-output engines
Suitable for everyday use and operates smoothly up to over 30 PS / 25 Nm
This 23-tooth version increases the gear ratio by approximately 5%
For stock and tuned engines
In the standard configuration, the clutch features 6 plates and 8 BGM PRO XL springs with a spring rate of 6.5 N/mm. This results in a setup that is comfortable to operate in everyday use while also being designed for powerful wide-frame and early large-frame engines. Power ranges exceeding 30 PS and 25 Nm are easily handled with this configuration.
Riders with significantly more powerful engines or those seeking even more performance headroom can easily adjust the spring set. A proven next step is the combination of 4 BGM PRO XL and 4 BGM PRO XXL springs. This allows the clutch to be specifically tailored to engine power, torque, and the desired lever feel.
Standard Setup
| Plate Set |
6 plates featuring modern KTM clutch plate technology |
| Springs |
8x BGM PRO XL |
| Spring rate |
6.5 N/mm per spring |
| Load capacity |
Designed for setups over 30 PS / 25 Nm |
| Overall height |
45.6 mm |
| Primary |
Original primary sprocket with 67 and 68 teeth |
| Clutch sprocket |
23 teeth, helical |
| Sprocket type |
Compatible with standard Cosa2 sprockets |
23T BGM PRO custom solution for a longer gear ratio
The 23-tooth sprocket is a special solution from BGM PRO. This gear ratio was not available as standard equipment on classic Wideframe and early Largeframe engines. The 23T sprocket increases the overall gear ratio by approximately 5% compared to the original 22T version: from 3.04 to 2.91.
This works very well with high-torque engines that can handle a longer gear ratio smoothly. The engine runs at a slightly lower RPM at the same speed, making for a more relaxed riding experience, and powerful touring setups benefit from a longer gear ratio.
22T or 23T?
22 teeth: corresponds to the original gear ratio and is the right choice for stock-like engines or riders who want to keep the original gear ratio.
23 teeth: a special BGM PRO solution for an approximately 5% longer gear ratio, from 3.04 to 2.91.
Both variants are designed for original primary sprockets with 67 and 68 teeth.
Any standard Cosa2 sprocket can be used.
Cosa2 sprocket type: flexibly adjustable
The clutch uses the standard Cosa2 sprocket type. This allows standard Cosa2 sprockets to be used to adjust the gear ratio. This makes the clutch not only suitable for the standard 23T configuration but also for engines where the gear ratio may later need to be specifically adjusted to match torque, tire size, intended use, or personal riding style.
Fits under the original clutch cover
An important advantage for Wideframe and early Largeframe engines: The original clutch cover can still be used. This keeps the engine’s exterior close to the original; no spacers or modifications to the engine case are required. This makes the clutch particularly appealing for restorations, touring-ready engines, and subtle performance upgrades.
Wide Range of Applications
The Sei Giorni GP clutch is designed for Vespa Wideframe models from 1953 onward, as well as early Largeframe models with a flat clutch. It thus covers an unusually wide range of classic Vespa engines: from stock-like setups to powerful street engines with modern cylinder and exhaust combinations.
| Vespa Wideframe |
VM, VN, VL, VB, model years approx. 1953–1959 |
| Early Vespa Largeframe |
VNA, VBA, VNB, VGLA, VBB1T |
| Motovespa 125S |
V72M, V58MS, V60MS |
| Motovespa 125N |
V56M, V58M, V60M, V101M |
The key factor is the flat clutch design in combination with the original primary sprocket with 67 or 68 teeth.
Customizable
The clutch has a modular design. Using different friction plates, steel discs, spring combinations, and Cosa2 sprockets, the kit can be adjusted to match engine power, installation space, desired lever feel, and gear ratio. For most high-performance street engines, the included setup is already very suitable. Riders with significantly higher torque can specifically combine stiffer springs.
Technical Details and Tuning
Ships with 8x BGM PRO XL springs
Optional stiffer tuning available with 4x BGM PRO XL and 4x BGM PRO XXL springs
Steel washers available in 0.8 mm, 1.0 mm, and 1.5 mm
Friction plates available in 1.4 mm and 1.9 mm
All standard Cosa2 sprockets can be used for gear ratio tuning
The clutch is shipped with a 19 mm-high lining package (measured in absolute terms)
Tip: If the clutch is to be used in later Vespa large-frame engines such as the Sprint, PX, Rally, or Cosa, the correct overall height can be achieved by installing a 17 mm lining pack.
This allows the clutch to be precisely tuned depending on the engine, installation space, and intended use
12 plates for lower load per plate
The 12 tabs on the friction linings distribute the force over a larger area within the clutch basket. This reduces localized stress on the contact surfaces and ensures smooth, controllable power transmission. Especially for engines with higher torque, this design is a key component for smooth disengagement and even engagement.
Installation Instructions
The clutch is delivered fully assembled
Before installation, check the primary sprocket for 67 or 68 teeth
Check the clutch cover, pressure plate, and disengagement travel
When installing a new friction pack, use the appropriate transmission oil and adjust the clutch properly
For very high-performance engines, adjust the spring combination to match the torque and lever feel
Conclusion
The Stingworks Sei Giorni GP is the original among modern clutch solutions for Vespa Wideframe and early Largeframe engines with a flat clutch. In the 23Z version, it combines proven Stingworks clutch technology with a special BGM PRO gear ratio solution that was never available as standard equipment. The gear ratio is extended by approximately 5%, from 3.04 to 2.91. Together with 6 friction plates, modern KTM friction plate technology, a reinforced hub, and a Cosa2 sprocket, this creates a robust, everyday-ready, and flexibly tunable clutch for stock, touring-ready, and heavily tuned engines.
FAQ
Yes. We supply the original Stingworks Sei Giorni GP clutch for Vespa Wideframe and early Largeframe engines with a flat clutch.
The 23-tooth sprocket is a special solution from BGM PRO. This gear ratio was not available as standard from the factory. It reduces the final drive ratio by approximately 5%, from 3.04 to 2.91.
Any standard Cosa2 sprockets can be used. This allows the gear ratio to be flexibly adjusted to the engine and intended use as needed.
It is designed for Vespa Wideframe models from around 1953 onward, as well as early Largeframe models with a flat clutch, including the VM, VN, VL, VB, VNA, VBA, VNB, VGLA, and VBB1T. Compatible Motovespa 125S and 125N models are also covered.
No. The clutch is designed so that the original clutch cover can be reused. No modification of the cover or engine casing is required.
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