Originally Posted by
TrojanHorse
I'm going to go a little in the opposite direction and say - good for you and definitely do your own work on your bike. You totally screwed up your shifting but you learned that you can work on your bike and the world won't end.
I did not tell the OP not to work on his bike, merely to do so in an informed manner. I reject the idea that a random action that one then finds out was ill advised is productive "learning." The lesson is not that you can do things to a bike without knowing the impact and the world won't end, but rather that doing so can cause problems, and it's best to proceed armed with at least some info and guidance.