Clutch expiry at Lydden

Pic shows the remains of the clutch on my 175, following a last lap loss of drive with sounds of scrunching and munching.... Clutch had an un-modified 4 plate basket with 9 springs 15/16 " long and no washers in the cups. Steel plates throughout. Tensile failure at the base of the basket sides caused the clutch components to release into the chaincase and lock the primary chain. The chain promptly snapped and punched through the chaincase. The big retaining circlip is still locked between the outer plates.

Anyone know of similar incidents or what the solution is to strengthen the basket against recurrence?

On another tack, the tales I heard at Lydden re Shell Optimax and fibreglass tanks explain the major problems I have experienced recently with both bikes. Avgas appears to be an essential must-have for use with fibreglass.

Chris

Yes I've had similar... Chris make your first clutch plate into the drum a smaller dia, or put a dogged on the outside plate in first. Don't try a cram a lot of plates in either try and get away with minimum rather than maximum no of plates. Get a band brazed around the the outside of the drum at the circlip end about 4mm thick. Beg steal or borrow a 'Tom' spring carrier plate, throw away the outer plate and screws x3...
Read your pm
Mike

Thanks Mike - much appreciated.

Chris