OK, own up, who put the standard 520 sprockets in the box with the 525 chain?
Not amazingly impressed.
Loosen front sprocket nut, split chain, drop rear wheel, remove rear sprocket, remove front sprocket (bytch), fit new sprockets, fit rear wheel, put new chain on.... Luckily I noticed the play in the chain/sprockets before I rivetted the new chain on!.. BOLX.
Ok put it all back as it was, waste of a couple of hours
Also lucky I had clip-link (temporary) on old chain so I could re-fit.

Hmm, not like I can ride to the shop to get the correct parts.
I don't know how much thicker the 525 sprockets should be? but I'm sure they shouldn't be the same thickness as the original 520 sprockets?

Before I do it all again, I will drill a piece of metal for pulling front sprocket off.

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PCV REPLACEMENT ECU WITH 04 WIRING LOOM STAGE1&2DNA GEL SEAT INSERT LOWERED 20mm FRONT+REAR CLUTCH ARM MOD
FORKSPRING SPACERS TALLER SCREEN THROTTLE GRIP CAM MOD DISTANZIAS 46TOOTH REAR SPRKT
SPEEDO HEALER 30MM HANDLEBAR RISERS TOPBOX MOUNT 08 XTX SORTED, ALMOST.
...SHEEPSKIN - Because a pain at the rear is not just a moany pillion.