How to measure a gypsy?

[double u]

from the horses mouth in Piangipane I had:
quick's 10mm gypsies are for ISO chain but will fit DIN766 too. if you look closely at the gypsies the "shoulder" is really radiused & this might account for both 10mm chains working. we (Austrian Quick distributors) have had no claim with either of the 10mm chains not working on a Quick gypsy. if in doubt go ISO though.

[LongRange]

Originally Posted by double u

from the horses mouth in Piangipane I had:
quick's 10mm gypsies are for ISO chain but will fit DIN766 too. if you look closely at the gypsies the "shoulder" is really radiused & this might account for both 10mm chains working. we (Austrian Quick distributors) have had no claim with either of the 10mm chains not working on a Quick gypsy. if in doubt go ISO though.

Thank you. I certainly was in doubt, but after checking the gypsy against examples of known ISO and DIN 10mm chain I have no doubt that this particular gypsy is primarily designed for DIN. It worked OK with my previous ISO chain, in the sense that it hadn't thrown the chain in the few months that I have owned the boat, but DIN chain is a much better fit, and it feeds much more smoothly and quietly.

Perhaps the previous owner changed over to a DIN gypsy at some point, for reasons unknown? It is certainly a Quick-type gypsy, 10mm, and it is DIN.