Yes. The Park Tool is about a $35 wrench. You will need drive bits to fit the allen sizes you need. I would not worry about it if you are just concerned about over tightening cables. (IMO) You just need to get a feel for that ( I am not a real mechanic ). But if you are going to get into bigger bike maintenace I would get one. The high end stuff is all spec'd. For instance if you install a Campy Record crankset and you tighten it it Shimano specs you may ruin it. I tend to tighten things to tight. What taught me to torque stuff is when I about crashed cause I tightened my headset bearing too tight. It is not like working on my old Western Flyer anymore.