HBS-shimano-fh-rm30-7-speed-freehub-bodyShimano FH-RM30 7-Speed Freehub Body Replacement Freehub Body for Shimano FH-RM30-7 Tourney 7-speed rear hubs. Genuine Shimano replacement part. Replaces the 'freewheel mechanism' part of your Shimano hub. You'll know it's time to replace your freehub body when the cranks spin without resistance because the freehub's internal pawls no longer engage. Fitting a new freehub body might save you having to replace a whole wheel. You fit or remove the freehub body with a 10mm Allen key after removing the 7-speed cassette.