Might be wrong but I think it's more than 20g. Food companies are no different than any other type of companies. They play tricky games & take advantage of the loopholes in the food regulations.
So for instance, correct me if I am wrong, they would use many types of sweetners in stead of sugar so that they'd get away with the "sugar free" label, or to reduce the amount of sugar listed in the nutritional facts.
In the case of Clif bars, how come it contains 44 carbohydrates while only having 20g sugar? Where are 40 carbs coming from?
Even if actually only contain 20g sugar, that's still equivalent to FIVE teaspoons of sugar in one bar.
May I suggest a cheaper & better alternative? One banana + one boiled egg before workout & you're good to go. Lots of other easy healthier alternatives & they cost a fraction of what these bars offer.