Can you tell us more about the rubbing? i.e. is it the chain rubbing against the front derailleur mech? Does it only happen when the chain is on the big front ring and the big cogs at the back cassette? And/or small front ring and small rear cog?
Forgive me if I am trying to teach my Granny to suck eggs here, but this is called cross chaining. Not sure about double chainsets as I am an old git living in amongst hills, so I stick to triples. Triples have a "half" gear on the shifter for the front mech to move the mech away from the chain without putting it onto the next ring, if that makes sense. It gives clearance between mech and chain.
On a triple, cross chaining is not recommended as the angle at which the chain runs would soon wear the chain and cassette. So we stick to only using the big ring with smaller cogs, and small ring with bigger cogs.
Anyway, if this was the problem, I am sure that even Evans would have picked up on that and explained it. Wouldn't they?