Originally Posted by pocky
The tandem is coming (Monday!) with 11-30t 8-speed, and I've already got a bunch of extra cogs to play with, so I'm planning to mess with it the same way as I get a feel for it and feel the need to customize.
See
http://www.sheldonbrown.com/k7.html . You can also do fun things like run 8 of 9 on a 7 wheel with 9-speed shifters and spacers!
Doesn't matter how fit or strong you are- A tandem requires low gearing for most of us mere mortals.
I have 48/36/24 linked to 11/32 rear cassette on 9 speed gearing on an offroad tandem that is used offroad. (Did try a 34t but we kept bending it). Although an offroad tandem- it is surprising how many hills require the 24/32 to get up them when on the road with slicks. And the 48/11 rarely gets used except on downhills. 48/11 with cadence of 100 will give us 30 mph and any faster and we will pointing downhill and coasting.
Providing you can get a low enough gear for your legs and your hills-it does not matter whether you have 7-8-9-or 10 speed on your Tandem. However quality of the components will. I have XT throughout and that has been upgraded from LX and that made a big improvement. However I got an XTR rear mech and although I did not notice a great deal of extra smoothness or ease in changing- there was a bit but not much- the life of that top quality unit has been well worth the extra.