Looking at the pics .... can someone tell me:

1. What are those black triangular things below the brake pad called and what's their purpose?

2. The brake pads are original and seem pretty hard. I'd like to replace them. Do I replace the assembly (pad, hex nut and holder) or can I just replace the pad? Recommendations as to pad type (i.e. Shimano, KoolStop, etc. welcome)

3. What is the purpose of that nub on the inside of the seat stay approximately 4 inches above the derailleur?


[ATTACH]SSC_1430.jpg[/ATTACH]