Bicycle Mechanics - Rear mech set up

I have got to set my rear mech up this weekend as I have changed various components and need to ge ti all running smooth again.
I have read various web articles about setting up and I am happy with the procedure, apart from the fact that most relate to mountain bikes with triple chain rings up front. They always state that adjustments to the rear should be made while the chain is in the middle chain ring.
I have a double chain ring road bike. Which is best to make rear mech adjustments, in the big ring or the little ring ?

Thanks

I have got to set my rear mech up this weekend as I have changed various components and need to ge ti all running smooth again.
I have read various web articles about setting up and I am happy with the procedure, apart from the fact that most relate to mountain bikes with triple chain rings up front. They always state that adjustments to the rear should be made while the chain is in the middle chain ring.
I have a double chain ring road bike. Which is best to make rear mech adjustments, in the big ring or the little ring ?

Thanks

You would set up the dérailleur limit screws when the chain is on the front big/rear small and on the front small/big rear for the appropriate high/low limit screws. Those screws limit how far the dérailleur will throw the chain at each end of the shifting. The shift levers themselves determine how much each individual shift will be, from cog to cog. After the high/low limit screws are set, and the shift cable tension is proper, then check the shifting for correct operation in both the small and big chainrings, up and down the entire cogset.

If you haven't seen it already, the Park Tool repair guide to adjusting dérailleurs is one of the best I've seen: http://www.parktool.com/repair_help/FAQrindx.shtml

You would set up the dérailleur limit screws when the chain is on the front big/rear small and on the front small/big rear for the appropriate high/low limit screws. Those screws limit how far the dérailleur will throw the chain at each end of the shifting. The shift levers themselves determine how much each individual shift will be, from cog to cog. After the high/low limit screws are set, and the shift cable tension is proper, then check the shifting for correct operation in both the small and big chainrings, up and down the entire cogset.

If you haven't seen it already, the Park Tool repair guide to adjusting dérailleurs is one of the best I've seen: http://www.parktool.com/repair_help/FAQrindx.shtml

A big thanks deserved !!
It was a very clear and excellent article, probably the most useful I''ve seen on the subject. Instead of using my own intuition when settting up this weekend just gone, I followed the steps in the article religously, and I know have a very smooth and sweet shifting drive train which I tested on a 32 mile ride this Sunday.

Thanks again