SIP Scootershop got together with Denis Innocente at DRT and took on solving a problem concerning Largeframe models produced between 1946 and 1957. The original clutch units are no longer available for these models. The only chance, up till then, to obtain replacement was on the used market, at mostly astronomical prices. We have now developed and produced together a new version of this clutch type with many 'state of the art' updates which guarantee a comfortably ideal light clutch action, even with increased performance motor set ups.
The precision CNC milled components and the newly developed clutch base plate ensure an optimal transfer of power through the clutch cluster assembly. The version we produce especially for the VESPA GS models has an inner mounting cone profile perfectly dimensioned to fit the GS models crankshaft end profile. The amount of spring guides in the clutch basket has been raised to 12 in the 86mm outer diameter version, 24 in the 96mm outer diameter version and 28 in the 115mm outer diameter version. The original clutch springs, supplied originally with the third generation PX EFL/Lusso models and the COSA, are supplied for use with these clutch kits. A total of six springs are sufficient for standard motor set ups in the 86mm outer diameter version, twelve springs in the 96mm outer diameter version and fourteen clutch springs in the 115mm outer diameter version. For more performance orientated motor set ups we recommend the maximum number of springs be included in your basket as is possible! The relative cohesive pressure between the clutch plates will be increased and clutch lever operation is made easier. The slightly modified positioning of the clutch spring cups leads to a pre-load effect on the springs and helps effectively to eliminate spring rattle during operation. While assembling the clutch cluster a small screwdriver can prove helpful to position the clutch springs accurately. The smaller clutch back plate bush, including needle bearings is replaced with a larger, more modern version, without needle bearings. Overhauling your motor and clutch plate replacement is made much easier. The thrust washer from the later VESPA models is also included with this clutch kit. If you are ordering this clutch assembly for the V 98/V 1-33T or the VN/VL VESPA models, the relevant primary drive cog specific to you particular model is included in the delivery.
The original primary drive cogs can be used with the VESPA GS 160 and PX models. Some clutches also need to be equipped with both clutch friction and separation plates. Regular VESPA PX 200 plates are ideal, but need to be modified slightly to fit properly. Alternatively, the DRT clutch plates are also fit for the job, without any modification necessary. Some VESPA models may need slight modification in order to fit these clutch kits, with either a clutch cover gasket surface spacer being used between the clutch cover and the crankcase or through removal of metal from the inner side of the clutch cover itself.
Conclusion: A timely update for all those VESPA models for which the original clutches are no longer produced or available. Clutch snatch has also become a thing of the past with the added bonus of the clutch basket no longer being able to fly open due to the increased centrifugal force created by a tuned motors higher rev. range. The freedom of choice offered by the possible variation and experimentation with differing strengths of spring enables an adjustment ideally suited to the set up of your particular motor and individual need.
SIP-TIP: Do not forget to order new clutch friction and plain separator plates! You can also order varying strengths of original clutch springs to find your ideal clutch assembly set up through experimentation. A strengthened clutch circlip is also recommended.
SIP community user 'Horst Binnig' Vespa Veteranen club Germany on Art. No. : 93250000: "I have this clutch mounted to my VESPA GS 4. The DRT clutch seperates cleanly, is easier to dose and compared with the original PIAGGIO item is very easy to operate. Exactly that is a great advantage!
SIP community user Robin Davy, Vespa acrobatic team, Vespa Oldtimer Freunde Munich, 03/10 : "DRT clutches are the only ones we use on our Vespa acrobatic scooters. The demands of a show scooter would mean the end for any normal clutch.
SIP man Max, SIP trip to Toskana 2011 on Art. No. 93250000: I'm completely convinced by the abilities of this clutch and have included it with a Malossi 210cc cylinder, a big carb. and a SIP ROAD exhaust in my VESPA Rallys motor set up. On the SIP trip 2011 I ended up pushing our Toni mile after mile up the 'Stiftersjoch' mountain pass because of his burnt up original PX clutch-until my thigh muscle gave up, the DRT clutch didn't though!