A few weeks ago, a friend asked me whether I could help him sort out a problem with his bicycle, as it wasn’t able to go into either the top or bottom gear; in other words, the rear mech (derailleur) would not shift into the smallest cog or the biggest cog.
This reminded me of the first time I tried to sort out my own rear mech when it wouldn’t shift into the biggest cog. I made a total arse up of it because I did not know the hierarchy of things you should run through, in other words you need to go through a set of instructions in a specific order to sort something like this out. I ended up twiddling with pretty much every screw, including the b-screw, because I was reading a book that described what each set of screws did (limit screws, H/L screws, b-screw etc), but didn’t tell me the order that you should do things in.
Today, I was sorting out the V-brake on someone else’s bike, which is something I rarely do as I don’t tend to do MTB stuff, so needed teh interwebs to come to my aid, and came across a page with the correct hierarchy. Job done nice and easily. I could repeat it all here, but hey, that would be both a waste of my time and stealing from someone else, so I shall go no further and merely re-direct you to this page which should have you up and running in no time: