Not sure this is the right section but,
I replaced my rear v-brake pads today and ran into a real and potential problem.
The new Koolstop Salmon pads turned out to be thicker than the original Shimanos, I had to loosen some cable out of the end clamp to get the brake back together.
I went out for a ride, but the new pads felt useless, however hard I pulled on the rear brake lever.
Eventually I worked out what was happening - I have an S&S coupled frame and the rear brake cable uncouples at an SJS cable joiner between the arms of the rear brake i.e. between the rear noodle and the end of the cable. I had set the cable up so that the joiner was too near the noodle.
Pulling on the brake was bringing the joiner up against the noodle before the brake pads hit the rim hard enough to stop me.
Thinking about it I could have got the same problem later, needing to pull more cable, as the rear pads wore down...
So beware all you S&S coupled frame owners.
If you adjust the rear brake cable and have a cable joiner in between the rear brake arms, watch for it hitting the noodle as you put the brake on.
Don't repeat my mistake!