I have an old Cannondale road bike I use as back up and for visiting friends. Now living in a hillier area than before and the gears and my (and friends) aging legs don't handle them too well. So I'm looking for the smart way to upgrade. Currently have downtube shifters, Suntour components, double chainwheel (40/50) and 6 sprocket cassette (15-30). So gear inch range is 36-90. Ideally I'd like to expand that range at both ends.
Is there some reasonable way to do this? I'll take the bike to my local shop but wanted to get some independant expert advice first.