You're about to get "ripped" here as well, heh.

Is it just your shoulder? Can you do some leg work? Something like this: http://my.menshealth.com/challenges/leg-matrix

What do you normally do for your shoulder work? Any cable rotator work before any pressing?

I just added these to my leg routine and I'm loving them. I've got my wife doing them, too, so that's pretty awesome.

I have recently changed my routine from strength training to a volume routine (less weight, more sets, more reps). Since making that change, I have noticed that my sets on the bench press end when my triceps fail (not the case when I was strength training).

What is the most likely cause:
1. form is bad; working triceps more than chest
2. form is good; chest fails first; able to do a few more reps using triceps; then triceps fail, which ends the set
3. form is good; triceps are weak; triceps fail before chest
4. some other explanation

5. Aids fire?

Good question though. I'm interested in the answer. I do a volume routine and usually my triceps are what fail. I do dumbbell bench though.

Did you change your grip width?

Don't believe so.

I have never seen someones chest 'fail' on bench, unless they tear a pec. Usually the weakness is either in the tricep (second half to lockout) or off the chest (front delt). We need a video to really be able to diagnose. We need to see grip width (as Lew mentioned), how your elbows are tucking (or flaring) as well as overall bench setup. I think it would be cool if guys started throwing up some videos on PR's, etc. Tuck e-peens away and be able to help each other with form, setup, etc.

Is there more info regarding cable work for shoulder warm ups?