Originally Posted by box opener

There is no problem on chain downshifting for the rear derailer, it works fine ever since, which means shifting towards the smaller cog for my bike, and which means the tension on the chain is further relieved, the problem is that when I am going up hill, I hope the rear derailer can shift the chain to larger cog that could make pedaling easier for me, and this is where the failure of derailer most take place. Do you have any idea on improving that, how do you think of replacing the indexed rear derailer to friction derailer? does that help evidently?