You can get the 3 plate clutch to work but you need heavy springs and careful setting up. Without some sort of clutch lightener, you will end up with a heavy clutch lever.

Thank you Alan so I need to get the thinner plates, do they then work ok with the existing springs?

My recently acquired Cub has 14/58 secondary ratio, with a 15 tooth primary. It was built up in 1997 and hardly used since (apparently) Yes, the clutch struggles if you are heavy on the kickstart, but a gentle stroke gets her started. I have recently fitted the four plate clutch with new springs and pressure plate, which made a considerable difference, and I have since found that the friction material on the back of the clutch basket has all but disintegrated. This is away to be re-lined, and I'm confident this will be another step forward.

As for the effect of the gearing, I'm very happy with the low speed this gives. The bike has a low 2nd gear as well, which is quite usable in sections. Unfortunately, the trade off is that top speed is about 25mph!

Mark

Thank you Alan so I need to get the thinner plates, do they then work ok with the existing springs?

The standard clutch effectively has 4 plates.. The back of the drum acts as plate, adding another set of plates increases theoretical torque capability by 20 % for the same spring load. This should just about compensate for the increased torque due to the reduced engine sprocket. I havent used a four plate clutch so cant say for sure.