This adds an extra friction and steel plate to your 50 clutch
In many cases 80 or 93cc top ends have been fitted to 50 bottom ends.
Usually the clutch will slip as the 50 had one less of each plate - this conversion rectifies that problem in a trice.
Of course if you have tuned 93cc bike, an 80 that's pushing the power or very rarely an ultra-tuned race 50 then you might need our other option with yet another steel and friction plate. This will be listed separately as the 16+ bhp clutch.