The overall design of the SIP 'Ultrastrong' clutch basket is based upon that of the MMW 'Superstrong' type and is also constructed by the MMW team in their workshop. Up till now this type of clutch was only really suitable for dedicated race use, but now thanks to a slimmer design can also be considered for use as part of a road-going touring motors set-up. The SIP version of the 'Superstrong' clutch also does without the standard COSA II clutches baseplate, which has been replaced by a wave shaped baseplate. This type guarantees an improved clutch action in all situations. There are no rivets that can shear in its construction and ten COSA II clutch springs are installed to ensure effective clutch separation. As far as the materials and production quality of these MMW manufactured clutch bushes are concerned, these items represent absolute state-of-the-art motor components. In contrast to the original items, these are machine-pressed directly onto the base-plate of the clutch assembly. The bush itself is produced using a gunmetal (leaded red brass) material and the dimensions are much exacter than the original bushes. The bush must be pressed on the base plate and then reduces clutch grabbing or judder.
The main difference between the SIP and the MMW 'Superstrong' clutch versions can be found in the design of the clutch basket. The holes that are situated on the sides of the MMW versions basket are absent on the SIP type. The SIP clutch basket is also constructed using a more easily modifiable EC80 type steel, which is better known as F1 steel in Italy, as opposed to the MMW clutch basket which relies on a 42CroMo4 material for its manufacture. Our SIP clutch basket was conceived to fit more easily beneath the original clutch cover, with minimal modification being required. Some clutch covers/casings only need a couple of internal drip ridges to be carefully snapped off using a normal set of pliers! This clutch basket type has already been successfully proven in many motors capable of producing up to 30PS and even more. We have decided to call it a 'sport' clutch basket and not a 'race' type due to the fact that it is compatible for inclusion in the set-up of your motor with only minimal modification of your crankcases being necessary.
Conclusion : The well-proven MMW 'Superstrong' clutch type is at last available for road-going touring motor set-ups!
SIP-TIP : Do not forget to order new holding nuts, springs and woodruff keys. Fresh clutch plates combined with our very own clutch separation plates are also recommendable!