I'm getting less certain now-so happy to be corrected. Will take a better look at mine later
EIDT
and now i'm more convinced.
Look at this pulley:
https://www.ebay.co.uk/itm/VW-Audi-s...ce82%7Ciid%3A1
I know its not an Ur, but when the big bolt goes through this pulley, there is zero metal for it to clamp the pulley to the crank gear-it is held on by the four bolts.