PRO GUIDE
German specialist SIP Scootershop has developed an all-new high-tech clutch for Vespa Largeframe models - a " Supersport " version of the unbeaten BFA clutch . CEO Ralf Jodl explains that " with this clutch , the operating principle of the Vespa Largeframe clutch has been reversed . This is to connect less mass rigidly to the crankshaft and has the effect of improving operability . Together with four discs and nine springs , this is an almost indestructible clutch that is perfect for any application . " The whole thing fits under the original clutch cover of the PX and creates low mass on the crankshaft - with 4 clutch plates and a version available with a toothed flange . " The principle of the inverted Vespa Largeframe clutch is becoming increasingly popular - the grinding-in and separation behaviour are convincing . Unfortunately , these clutches are usually expensive , which increases the hurdle for the conversion . The aim of the " Supersport " clutch is to improve the ease of use , even on 20-30 hp engines . " The small company BFA from Italy made a start and was the first to reverse the operating principle of the clutch for Vespa Largeframe models . This means that the outer basket no longer rotates with the crankshaft , but the inner basket . " This principle was copied by several manufacturers , but the performance potential of the BFA clutch was never fully realised . SIP bought the clutch from BFA in 2019 and continues to have it produced by the same manufacturers in Italy . " The clutch works perfectly and can withstand power of over 70 hp without any problem . As the full performance of the BFA clutch is rarely needed , we decided to develop a similar clutch
with 4 discs . The aim was to transfer the perfect function and durability of the BFA clutch into a cheaper clutch that can easily transfer 50 hp . " The result is impressive and can only be matched or surpassed in function and durability by the five-disc BFA clutch . As with the BFA version , the pinion is bolted on with 12 screws . The four clutch plates are taken from the design of the Cosa clutch , SIP pads on aluminium sheets are used . " This has made it possible to increase the number of plates , both on the inside and on the outside basket , which increases the service life of the lining and separating discs . Nine springs provide sufficient contact pressure . CNC-manufactured individual parts made of high-quality aluminium ensure low weight and high-quality standards . The pressure plate is mounted on ball bearings and the pads can be changed while the clutch is installed . The " Supersport " clutch is available in different versions - suitable for the original clutch flange of the PX crankshafts or with toothing that forms an almost indestructible connection with the crankshaft . " However , this requires the use of a crankshaft with the same toothing . The toothing was first found on the crankshaft of the BFA 306 engines , but we now also offer it for a whole range of
crankshafts for standard PX engine cases . " If you want to combine the SIP ' Supersport ' clutch with a large primary gear Z64 from , for example , Polini , Malossi , BFA or other manufacturers , you can buy the clutches ' without gear ' ( 93440000 and 93441000 ) and combine it with one of the BFA gears ( 87482600 , 87482700 , 87482800 ). " The splined crankshaft stub cannot be combined with separate lubrication . The reason is that there is no washer clutch with
splines and inner diameter for M14 . The version for the original flange can be used with separate lubrication . " However , the protruding M5 countersunk screws may rub against the axle of the oil pump gear in the engine casing . To remedy this , it is sufficient to grind the axle of the oil pump approx . 0.5 mm lower . Alternatively , the protrusions of the screws can be ground off . " The ' Supersport ' clutch for the Vespa Largeframe models is the absolute high-end solution for a clean , reliable and easy-to-use power connection between engine and gearbox ," concludes Ralf . Features include a CNC milled aluminium outside basket , 12- pinion bolted with primary pinion , CNC milled steel inside basket , 4 full ' Cosa ' type pads , bearing mounted pressure plate , CNC milled aluminium cover plate top and bottom and nine springs . Clutch plates can be changed in installed condition and can be mounted with the original PX 200 clutch cover .
SIP SCOOTERSHOP GMBH Landsberg , GERMANY Tel : + 49 ( 0 ) 8191 9699969 martin @ sip-scootershop . de www . sip-scootershop . com
38 INTERNATIONAL DEALER NEWS - FEBRUARY / MARCH 2023 www . idnmag . com