I think you are right except the greatest amount of chain slack is small chainwheel - small cog and the least slack is large chainwheel - large cog. In your example this would be:
Max teeth = (52+26) = 78 Min teeth + (42+12) = 54 Difference = 24 teeth
But Zeus cranks usually could go down to about 38 T (some less), and with a 53T CW & 28T FW:
Max = (53+28) = 81 Min = (38+12) = 50 Difference = 31
In my experience, this is about all a Zeus Crtierium/ Campy NR will handle, and then only if the chain length is just right. So 36T is wishful thinking, but I think that's the way they calculated it. Don't know what the mimimum capacity means , though.
Regards,
Jerry Moos
Houston, TX
> Doesn't the "capacity" also refer to the difference in total teeth that
the
> derailleur can manage in extra chain length?
>
> Capacity= (Big chainring-small chaining )+ (Biggest cog - smallest cog )
>
> example ( 52 - 42 ) + (26 - 12) = 24T
>
> I would therefore assume that a derailleur marked 36 denti, could handle a
> different in chain length of 36. This seems like a lot, so maybe I'm
> wrong.
>
> Grant
> Toronto.ca
>
>
> Leonard Bulger wrote:
> The thing I find strange about all these derailleurs marked 36 denti is
> that I don't recall ever seeing a 36 tooth freewheel cog.