Joined: Jun 2011
Posts: 1,180
Likes: 0
From: Sunnyvale, California
Bikes: Bridgestone RB-1, 600, T700, MB-6 w/ Dirt Drops, MB-Zip, Bianchi Limited, Nashbar Hounder
1. Tension adjuster barrel (cf. Google the terms "derailleur tension adjuster barrel" and first link is to Park Tool website with video....)
2. Cog - synonym for gear or sprocket.
3. RD cable slack - != rd cable slack. RD in caps is an acronym for Rear Derailleur.
Good luck.