In reply to TobyA:
> but if you do, say, and 8b pitch and then 8c pitch together with an 80 mtr rope, can you say its an 8c+ or 9a pitch?
I don't think you can be that formulaic by simply adding two grades together and always getting the same answer. One variable will be what rests, if any, are like. For instance if there was a hands off at the belay then the linked route would be barely harder than the hardest pitch (just a bit more rope weight) - and that assumes the hardest pitch is the second one.
> Or the reverse - why isn't Chilam Balam a two pitch route?
A good climbing ethic in France and presumably Spain too is to end routes at a natural rest point. Not always a hands off but usually big bucket, sudden drop in steepness/difficulty etc. I presume there's nothing like that on this route.