What are those metal bits on the end of cables. I just replaced my derailleur and I had to take it off the cable. I know it only keeps the end of the cable together but then I don't want mine falling apart. I'm assuming it can't be put back on but could somebody tell me what they are called so I can look like an intellectual when I go to my local bike shop. I'm assuming that I will just have to clamp them on with plyers.