A technical overview of SIP Performance ‘COSA 2’ clutch linings, covering materials, compatibility and characteristics for Vespa Largeframe and Smallframe models, including comparisons with conventional linings and motorcycle plates.
Product Overview
Clutch linings with high-quality backing material for the clutches of Vespa Largeframe and Smallframe models.
With the wide range of modern clutch baskets available on the market for Vespa Largeframe models with a ‘Cosa 2’ clutch, virtually all requirements can be met. Whether it’s a powerful touring scooter or a 50PS racing scooter, the Vespa Largeframe clutch can be easily modified to function flawlessly under all conditions. The greatest performance reserves are provided here by CNC-machined, one-piece baskets, such as the SIP Ultrastrong or the MMW Superstrong. The only area that may still cause concern here is the clutch linings.
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• Lightweight, durable backing material
• Compatible with original Cosa2 clutches
• Available with various lining materials
Backing Material Considerations
Although there are a range of different linings made from various materials that certainly offer good properties, it is the backing material that causes problems. It is made of low-grade steel. This means that thin, soft and heavy plates have to transmit the forces and, when idling, rattle their way into the basket. If the basket is harder than the plates, the latter wear out very quickly.
High-quality clutch linings use aluminium as the backing material. The linings are also reinforced. To enable the use of such linings in the clutches of Vespa Largeframe models, modified motorcycle linings – for example, from the Honda CR80 – are available, or clutch baskets designed specifically for this type of lining are manufactured and sold. Unfortunately, these linings give rise to new problems. They do not run in smoothly, and the clutch is difficult to modulate. Furthermore, the lining itself is not as durable as the original Vespa Cosa 2 lining. Both issues are due to the larger inner diameter of the motorcycle linings. Whilst this increases the maximum transmissible force, the reduced friction surface area decreases durability and causes the linings to grip more aggressively. Yet, with the dimensions of the original Cosa linings, power of up to over 50 hp can already be transmitted.
SIP Performance ‘COSA 2’ Clutch Linings
SIP Performance ‘COSA 2’ clutch linings:
With the SIP Performance clutch linings, state-of-the-art carrier materials are incorporated into the clutch baskets of Vespa Largeframe models. The friction surfaces are mounted on aluminium plates. The tabs that engage with the cut-outs in the basket are reinforced. Consequently, the linings no longer suffer during idling due to the poor ratio of their own weight to the thin contact surface at the edges. The force is absorbed by a larger surface area.
In addition, the overall weight of the clutch is reduced, and the aluminium dissipates the heat generated during the running-in process more effectively. This makes the clutch less susceptible to thermal issues.
Clutch Lining Materials
Clutch lining materials
The SIP PERFORMANCE RACE ‘CR80’ ‘COSA 2’ is available with two different lining materials: “sintered” and ‘black carbon’. The sintered material is a very high-quality and durable material for high-performance everyday engines. It offers a good balance between power transmission and bedding-in behaviour. The “black carbon” is perfect for use on the racetrack. It is more heat-resistant and can still be bedded in with precision even at full throttle. However, it requires more pressure to transmit the same force as the linings made from sintered material.
Advantages Over Conventional Linings
Advantages over conventional “COSA 2” linings:
• less wear on the plates
• lower overall weight
• better heat dissipation
Advantages Over Motorcycle Plates
Advantages over motorcycle plates (e.g. CR80):
• better bed-in behaviour
• less wear on the plate surfaces
Conclusion
Conclusion: The perfect complement to modern clutch baskets. Extends the service life of the plates, even in high-performance engines.
Shop Link
Shop link: https://sip.shop/kulu
