MY Service manual clearly indicates that either is ok.
Can anyone verify this? From experience?

I thought that the link inner width (pin/roller length) would be greater on the 525. How can both fit properly on the standard sprockets?

I want to order a 'good' o, x, or z ring gold chain to replace the Honda one and don't want to buy the wrong size.

thanks...

Jeff,

Your right, the service manual specifies 520 and 525, but the sizes are different between DID and RK. I would suspect that a 520 is a 520 is a 520, but based on what the service manual says, I would get a 520 in RK and if your getting a DID, get a 525.

You should be able to cross reference the model #'s in the manual to come up with a Regina or other chain of the same dimensions (I would guess?).