Maxing out on squats (because the bar hurts me)

JoRocka

The picture below is about the best I could find for bar position (high vs. low bar). Not only will the pad mess with stability, it also will change angles of the lift. You wouldn't think a 1/2 an inch would make a difference but it does.

You also may simply need to build up your traps a bit also.

this.

Sounds like bad bar placement- and odds are you don't have any back mass. Ladies- WORK YOUR BACKS!!!!!

And FYI- neither of those pictures are wrong- it's high vs low bar- not that one is right one is wrong.
The ultimate goal is to have the bar path travel straight up and straight down- doing high vs low makes a difference on torso angle. But if you not the high bar (left) it's still not on the shoulders and neck itself.

I also wouldn't' use anything more than a thing towel/t-shirt between the bar if I had to use anything.

Because at 120- you aren't anywhere near a place where you should be uncomfortable.