Downtube shifters to Handlebars

[xerxes]

I agree with Tim, Rapidfie/STI shifters weren't meant for drop handlebars. Mixing and matching newer shifters with older freewheels and cassettes can work if the sprocket centre to centre spacing is the same, for example: http://forums.bikeride.com/newreply.php?tid=4110, a Shimano 7 speed shifter may work with a Sun Tour "Ultra" 6 speed Freewheel. However, for this you'd have to find some old 7 speed shifters and an old 6 speed freewheel and it might be a lot of hassle.

Some more info: http://sheldonbrown.com/k7.html

I would be inclined to either stick with the current drivetrain and downtube shifters, or go the whole hog, buy a new rear wheel with a modern 10sp cassette compatible hub and the road mechs and shifters to suit. Even though I think that the ever increasing number of rear sprockets has more to do with marketing than real world performance, the sad fact is, that you can now only buy used or lower end drivetrain and shifter components with anything less than a 10 speeds for road bikes.