Dismantled my bike to try and take a look at the crank bearing, as I fear it may be getting dry. Unfortunately at the stage pictured I could go no further.
The outer and inner rings appear to be separate, and locked against each other (presumably to set the end-float of the axle?). No idea what kind of fixing this is, so also no idea what sort of tool is required.
Does anyone recognise it?
Thanks!