How do I know if the hub gear bearings need adjustment?
You may need to adjust the bearings on the Shimano Nexus hub gear if the rear wheel develops play (more than 1mm at the rim) or it feels heavy to pedal (i.e., the hub is too tight).
You should check the hub gear bearing adjustment every 500 miles (800km), or every 3 months.
How do I adjust the hub gear bearings?
Please see Technical Bulletin 003 for more information.
You can also find this information in the Owner's Manuals:
https://gocycle.zendesk.com/hc/en-us/categories/360000014933-Safety-and-Owner-s-Manuals