Bring a large pot of salted water to a boil. Cook the corn for 3 minutes, then drain and immerse the corn in ice water to stop the cooking and set the color. Once corn is cool, slice the kernels off of the cob and place them in a large bowl.
Mix the avocados in lemon juice and add to the corn. Add the tomatoes, red peppers, onion, jalapeno, black beans, and lime zest into the bowl.
Whisk the lime juice, olive oil, 2 teaspoons kosher salt, black pepper, garlic, and cayenne pepper together in a small bowl. Using a rubber spatula mix the dressing with the vegetables. Keep in the refrigerator until ready to serve.