OSSA MJ rear sprocket for Ossa TRi 2015-2016 MJ Corse MJ.429 €55.02 High quality duraluminium (ergal) rear sprocket for Ossa TRi 2015-2016 with chain pitch 520 and with number of teeth from 30 to 50. Select the chain pitch and number of teeth you need by clicking below. Add to cart