My pizza crust is very hard and tough and not light and crispy, why? I'm having trouble getting my pizza crust light , airy and crispy. I'm not sure if it's the mixing of the dough because I'm using a smaller mixer 20qt as opposed to my old 60qt. The bowl is not smooth and shiny and the dough hook doesn't appear to get close enough to the bottom of the bowl. It looks like the bowl was used to for everything except for making dough. 

Do these sound like conditions that would cause my crust to be tough? The dough is stiff and is difficult to work with when I remove it from the refrigerated proofing box. It's elastic like.

This is frustrating because I owned a pizza shop a year ago; I had a recipe from New Haven and my crust was perfect: light, airy and crispy. I now reopened in a new location with a different oven and I'm still using my old recipe and the pizza crust is awful and I can't figure out why.

The recipe is as follows:

4-gal water
4oz yeast cake
12oz salt
50 lbs flour-gold medal bromated bleached flour full strength


The recipe is fine since I had a perfect new haven style thin crust using it for a year at my old location.
Your 60 qt mixer is going to mix dough at a much different rate than your 20 qt, even if their rotation speeds are the same. Your hook to bowl clearance shouldn't be an issue unless you're getting an excessive amount of crusty dough on the bottom of the bowl. The condition of the bowl is negligible too. Most likely your issue will be over/under development of your dough. 

Does the dough from your other location pass a windowpane test? How about your new dough? Assuming your relative humidity, proofing box temperature, and oven temperatures are the same, its going to be dough development. Experiment with different mixing times until you find the sweet spot. Also, if you are scaling a recipe down, occasionally you'll need to adjust hydration levels just a touch.