The thing is that you lose more than just salt when you sweat, and for some people, being low in any or all electrolytes (potassium, magnesium, calcium, and sodium) can lead to cramping and/or reduced performance. So if you're a really salty sweater than maybe extra sodium is good for you, but you also should look into consuming something with all the electrolytes. A lot of us get plenty of dietary sodium, so maybe that's why some people do better with cramps if they pay more attention to consuming foods rich in potassium, for example. You might not need straight salt or the margarita bloks, just a general electrolyte supplement with some calories and then a salty snack after the ride, or at least not a low salt diet.