Part No. starting with R require rear sprocket replacement. Use sprocket bolt pattern 5-holes M10 PCD 100mm ID
76mm. Except for Part No. RA70600715, R70600B715 and RA70600515 that use oem sprocket, and Part No. RA70550757,
RA70600757, R70600B757, RA70600557, RA70550756, RA70600760, RA70600749,