Rear Wheel Internal Spacer AP8176101
Fitment - RSV 03-10, Tuono Factory 06-10, RSV4 09-20
Genuine Aprilia Rear wheel internal spacer, part number AP8176101, item number 16 in the diagram.
This is used to prevent the wheel from being squashed together when the spindle nut is torqued to it's correct specification and allow the wheel to spin freely.
Here at AP Workshops we recommend 100Nm for the rear wheel, not 120Nm as stated in the owners workshop manual as the higher setting can potentially damage the spacer.