Rear - Front sprockets MJ rear sprocket for YCF Bigy Factory 190 ZE MX MJ Corse MJ.310 €28.19 High quality duraluminium (ergal) rear sprocket for YCF Bigy Factory 190 ZE MX with chain pitches 415 and 420 and with number of teeth from 30 to 46. Select the chain pitch and number of teeth you need by clicking below. Add to cart