Thanks, guys - the replies sort of confirm that I am on the right track with the cable tension. I'll probably take it into the shop this weekend - they did offer the free tuneup, so I might as well take advantage of it.
Originally Posted by
zoink
I have a giant hybrid (rapid) with shimano quickfire shifters...if you press the downshift lever in all the way it will downshift two gears. If you listen you can hear it click twice. Probably the same thing with your SRAM shifter. Makes it easy to bang down through the gears, just have to get used to only flicking it until you feel the first click to downshift one gear on the cassette.
This is kind of interesting - could this be an intentional design element rather than poorly tuned shifters? (I used to work in IT, where one man's "feature" is another's "bug") I could see that being beneficial, but I would still want to tweak the tension - something like pushing in the lever halfway shifts once, pushing it in fully skips a gear. I'll have to mess around with that.
Thanks for the replies! Much appreciated