Riding a modern lightweight mtb in a cross race is rarely a significant disadvantage. Especially if its a 29er. The upsides counteract the downsides on most courses.
Weight on the hills and obstacles and squishy suspension on the fast flats would definitely be a disadvantage for me on that Supercross course - that said the steep descents through the trees would be a breeze.
Weight on the hills and obstacles and squishy suspension on the fast flats would definitely be a disadvantage for me on that Supercross course - that said the steep descents through the trees would be a breeze.