How do Sora shifters work?
Being a newbie and also having even more newbie-er friends of mine ride my bike, I've had the left shifter jammed twice now. Bringing it in to the shop and having them fix it is fine and all but if it's at all possible I'd like to learn how to fix it myself, as it seems to be the only thing that I can't find out how to do in some book or on the internet. So two questions:
1. How do you fix a jammed sora shifter?
2. Where would I be able to find info on how the thing actually works/how to fix it?
Thanks!